Environment Impact Assessment Report for Exploratory Drilling of Shale Gas and Oil Wells In KG Basin West Godavari District, Andhra Pradesh 2016

Transcription

1 Environment Impact Assessment Report for Exploratory Drilling of Shale Gas and Oil Wells In KG Basin West Godavari District, Andhra Pradesh 2016 Oil and Natural Gas Corporation Ltd., (A Govt. of India Enterprise) Corporate Health Safety and Environment ONGC, Delhi

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3 TOR and point wise response for the project Exploratory Drilling of two Shale gas and oil wells in KG Basin, West Godavari District, Andhra Pradesh ToR No.J-11011/37/2016-IA II(I) dated 19 th April 2016 Sl.No. Point Compliance 1. Executive summary of a project Provided in page no Project description, project objectives and project benefits Cost of project and period of completion Site details within 1 km of the each proposed well, any habitation, any other installation/activity, flora and fauna, approachability to site, other activities including agriculture/land, satellite imagery for 10 km area. All the geological details shall be mentioned in the Topo sheet of 1:40000 scale, superimposing the well locations and other structures of the projects. Topography of the project site. Details of sensitive areas such as National Park, Wildlife sanctuary and any other eco-sensitive area along with map indicating distance. Approval for the forest land from the State/Central Govt under Forest (Conservation) Act, 1980 as project involves forest land. Distance from nearby critically/severely polluted area as per Notification, if applicable Status of moratorium imposed on the area. Doses proposal involve rehabilitation and resettlement? if yes details thereof. Environmental considerations in the selection of the drilling locations for which environmental clearance is being sought. Present any analysis suggested for minimizing the foot print giving details of drilling and development options considered. Baseline data collection for air, water and soil for one season leaving the monsoon season in an area of 10 km radius with center of Oil Field as its center covering the area of all proposed drilling wells. Climatology and Meteorology including wind speed, wind direction, temperature rainfall, relative humidity etc. Details of Ambient Air Quality Monitoring at 5 locations for PM 2.5, PM 10, SO 2, NOx, CO, VOCs, Methane and non-methane HC. Soil sample analysis (physical and chemical properties) at the areas located at 5 locations. Provided in page no.6-11 Rs. 93 Cr. Site details provided in page nos. 25. Proposed sites are in agricultural lands. No habitation within 1km of the proposed sites. No national park/wild life sanctuary/reserve forest /eco sensitive area near the locations. Topo sheets with 1:30000 are given at Fig no. 3.1 in page no. 24. No national park/wild life sanctuary/reserve forest /eco sensitive area near the location. The proposed location is not falling in the forest area NA No Drilling locations are selected on the basis of interpretation of G&G data Air : Page nos: Water : Page nos: Soil : Page nos: Page nos:30-33 Page nos: Page nos: 38-40

4 Ground and Surface water quality in the vicinity of the proposed wells site. Measurement of Noise levels within 1 km radius of the proposed wells. Vegetation and land use flora/fauna in the block area with details of endangered species if any. Incremental GLC as a result of DG set operation, flaring etc. Potential environmental impacts envisaged during various stages of project activities such as site activation, development, operation/ maintenance and de-commissioning. Actual source of water and Permission for the drawl of water from the Competent Authority. Detailed water balance, waste water generation and discharge. Noise abatement measures and measures to minimize disturbance due to light and visual intrusions. Details of waste water generation, treatment and utilization/discharge for produced water/formation water, cooling waters, other waste waters, etc. during all project phases. Details of solid waste management for drill cuttings, drilling mud and oil sludge, produced sand, radioactive material other hazardous materials, etc. including its disposal options during all project phases. Page nos:35-38 Page nos: Page nos: Page nos:51-55 Page nos:55-60 Page nos: 17 & 78 Page no: 79 Page no:78 Page no: Disposal of spent oil and lube. Page no: Storage of chemicals and diesel at site. Hazardous material usage, storage and accounting. Commitment for the use of water based mud (WBM) only. Oil spill emergency plans for recovery /reclamation Page no:18 Page no:78 Page no: H 2S emission Control Page nos: Produced oil/gas handling, processing and storage/transportation Details of control of air, water and noise pollution during production phase 30. Measures to protect ground water and shallow aquifers from contamination Whether any burn pits being used for well test operations Risk assessment and disaster management plan for independent reviews of well-designed construction etc. for prevention of blow out. Blowout preventer installation. Exploratory Drilling. No production at this stage NA Page no: 19, Waste pit is covered with impervious HDPE sheet. Flare stack is used for production testing, Page no. 22 Page nos: Environmental Management Plan Page nos: 74-84

5 34. Total capital and recurring cost for environmental control measures Rs. 40 lakhs. 35. Emergency Preparedness Plan Page nos: Decommissioning restoration plans Page nos: Documentary proof of membership of common disposal facility, if any 38. Details of environmental and safety related documentation within the company including documentation and proposed occupational health and safety Surveillance Safety Programme for all personnel at site. This shall also include monitoring programme for the environmental A copy of the Corporate Environment Policy of the company as per the Ministry s O.M. No. J /41/2006-IAII(I) dated 26 th April, 2011 available on the Ministry s website. Any litigation pending against the project and or any direction/order passed by any court of law against the project. If so details thereof. NA All drilling rigs are certified for ISO-9001, OHSAS & ISO Documentation on safety, occupational health etc has been covered in the Management and procedure manuals available at drilling site. Corporate environment policy placed at Annexure -2 No

6 Table of Contents Sl.No. Contents Page No. EXECUTIVE SUMMARY INTRODUCTION 1.1 Present Exploration Scenario in Krishna-Godavari Basin Shale gas Drilling of shale gas/ oil well vis-a-vis normal exploratory wells Project details Objective and scope of study Project Benefits DRILLING TECHNOLOGY AND PROCESS DESCRIPTION 2.1 Drilling Process Drilling Facilities Drill site Drilling Mud Power Requirement Water Requirement Solids Removal Equipment Chemical and other storage facilities Manpower Logistics Drill cuttings and waste residual mud Domestic Waste water Hydro Fracturing An over view Production Testing Site Restoration BASELINE ENVIRONMENTAL QUALITY STATUS 3.1 Topography Baseline Environmental Quality Ambient Air Quality Meteorological scenario of the study area Regional Meteorological Scenario Noise Environment Water Environment Soil Environment Biological Environment Socio economic environment and Land use and land cover of the 43 study area Baseline Socio Economic Status ANTICIPATED ENVIRONMENTAL IMPACTS, EVALUATION & MITIGATION MEASURES 4.1 Introduction Impact assessment and mitigation measures Potential impacts on air quality 50 i

7 4.2.2 Mitigation measures Noise Environment Noise from the drilling rig Noise emanated by Machineries and equipment Noise from vehicular traffic Noise control measures Water Environment Land Environment Biological Environment Terrestrial Environment Aquatic environment Socio Economic Environment Environmental Impact Evaluation Ecology Environmental Pollution Socio economics Environmental Impact Statement Air Environment Noise Environment Water Environment Land Environment Biological Environment Socio Economic environment Positive Impacts Negative impacts Mitigation measures Post Project Monitoring Occupational Health Surveillance Program ENVIRONMENTAL MANAGEMENT PLAN (EMP) 5.1 Introduction Site preparation Rig mobilization & de-mobilization Emissions and discharges from actual drilling operations Solid Waste Management Disposal of spent and Lube oil De commissioning and Restoration of site Noise Management Biological Environment Socio Economic Environment Hydrogen sulfide Drilling Program safety guidelines Plans for post drilling well site operation and/ or abandonment Occupational Health Surveillance Program General Environmental Protection Measures RISK ASSESSMENT, EMERGENCY & DISASTER MANAGEMENT PLAN 6.1 Risk Assessment Methodology 86 ii

8 6.2 Risk Assessment Risk Associated with Design & Planning Risk Associated with approach road to drilling site Risk Associated with Rig Transportation and Building/ Dismantling Risk Associated with Drilling & Testing Disaster Management Plan Objective of Disaster Management Plan Disaster Management Plan: Key Elements Type of anticipated hazards Contingency Plan for Oil Spill Maximum Credible Accident and Consequence Analysis (MCAC) Dropped objects HSD release and fires Collisions Blow outs Modes of failure Identification of accident scenarios for consequence analysis Consequence Analysis: Pool fire due to rupture of diesel storage tank Methane gas release from Blowout Failure of Acetylene Gas Cylinder 110 List of Tables Table-1.1 Table-1.2 Table-1.3 Table-2.1 Table-2.2 Table-2.3 Table-3.1 Table-3.2 Table-3.3 Table-3.4 Table-3.5 Table-3.6 Table-3.7 Table-3.8 Table-3.9 Table-3.10 Table-3.11 Table-3.12 Table-3.13 Table-3.14 Table-3.15 Co-ordinates of the proposed PML blocks for shale gas/oil drilling Details of the proposed shale gas/oil exploratory locations Project Details Special additives and their functions in the mud Quantity of drill cuttings generated Typical composition of fracturing fluids Ambient Air Quality data at location: SU-SG-A Ambient Air Quality data at location: MA-SG-A Summary of the Air Quality parameters Micro meteorological Conditions at Location: SU-SG-A Micro meteorological Conditions at Location: MA-SG-A Monthly average weather parameters at Narsapuram IMD station Noise level survey at proposed location: MA-SG-A Noise level survey at proposed location: SU-SG-A Summary of the noise levels in the villages near the proposed locations Baseline Water Quality at the proposed location: MA-SG-A Baseline Water Quality at the proposed location: SU-SG-A Summary of the water quality parameters Baseline Soil quality at the proposed location: SU-SG-A Baseline Soil quality at the proposed location: MA-SG-A Summary of soil quality parameters iii

9 Table-3.16 Table-4.1 Table-4.2 Table-4.3 Table-4.4 Table-4.5 Table-4.6 Table-4.7 Table-4.8 Table-6.1 Table-6.2 Table-6.3 Table-6.4 Table-6.5 Table-6.6 Table-6.7 Table-6.8 List of Fauna Key Potential Impacts of Exploration Activities Impact Significance Criteria Activities Impacts/Risks Interaction Details of DG set & flaring emissions Resultant SPM, SO2, NOx, & CO in Ambient Air Noise Exposure Levels of drilling Rig Analysis of the drill cuttings Prediction of Qualitative Impacts on socio-economic environment Consequence Factor Probability of Occurrence (likelihood) Risk Assessment Criteria Risk Assessment Matrix Exploratory Drilling Standard Operating Practices for Blowout Event Classification Effect of Thermal Radiation Heat Radiation Effects due to Blowout of well List of Figures Fig-1.1 Map showing proposed locations for shale gas/oil exploratory drilling Fig-2.1 Typical on-land Drilling Rig Fig-2.2 Schematic Drilling Fluid Circulation Fig-2.3 Typical Drill Site Layout Plan Fig-2.4 Power Generator Set at Drilling Rig Fig-2.5 Solids Removal Equipment Fig-2.6 HDPE lined waste pit Fig:2.7 Hydro fracturing activity Fig-3.1 Topographic maps of the five proposed locations Fig-3.2 Map showing sampling stations along with proposed drilling locations in PML blocks Fig-3.3 Wind rose Diagrams of the proposed locations Fig-3.4 Wind rose diagram for the period to (source; Envitrans) Fig-3.5 Forest Distribution in Krishna district Fig-3.6 Forest Distribution in West Godavari district Fig-3.7 Forest Distribution in East Godavari district Fig-3.8 Land Use Land Cover map of Krishna district Fig-3.9 Land use Land cover Map of West Godavari district Fig-3.10 Land use Land cover Map of East Godavari district Fig-4.1 Output of Model- Suspended Particulate Matter (PM) Fig-4.2 Output of Model- Sulfur-di-Oxide (SO2) Fig-4.3 Output of Model- Nitrogen Oxides (NOx) Fig-4.4 Output of Model- Carbon Monoxide (CO) Fig-4.5 Impact Network for Air Environment Fig-4.6 Impact Network for Noise Environment iv

10 Fig-4.7 Fig-4.8 Fig-4.9 Fig-4.10 Fig-6.1 Fig-6.2 Fig-6.3 Fig-6.4 Fig-6.5 Impact Network for Water Environment Impact Network for Land Environment Impact Network for Socio-economic Environment Comprehensive Impact Network Identification of hazards in the process Organogram for On-Site Emergency Organogram for Off-Site Emergency Threat Zone for Diesel Tank Rupture Threat Zone for Failure of Acetylene Gas Cylinder v

11 Executive Summary India ranks as the world s 7 th largest primary energy producer and the 5 th largest energy consumer. The per capita consumption of energy in India is one of the lowest in the world (around 0.5 tonnes of O+OEG compared to world average of 1.8). With a population of 1.3 billion, the country s energy needs are expected to grow about four fold from 524 Million Tonnes of Oil Equivalent (MTOE) by Hydrocarbon sector plays pivotal role in India s energy sector with a 45% share in the commercial energy basket. Today, ONGC has been the largest producer of the oil and gas in the country, contributing 72.4% of the crude oil and 48.5% of the natural gas production. At present, over 78% of India s oil requirements are being met by imports. India s known oil and gas reserves form mere 0.8% of the world reserves of petroleum. Given the limited reserves and growing demand, India is heavily dependent on import of crude oil and petroleum products. Current demand and supply projections indicate that the level of self-sufficiency is likely to decline below 22% over the next few years. Substantial efforts are therefore necessary to boost the exploration activity in the country. Alongside, we also need to focus on unconventional hydrocarbon assets of the country namely CBM, Shale Gas, Gas Hydrates, etc. Presence of natural gas in the shale which are source to hydrocarbon found in conventional sand stone and carbonate reservoirs has been well known for a long time in number of sedimentary basins. However, it is only in the past few years that shale as significant source of oil and gas has drawn the attention of explorers. Recent success in USA and Canada in commercially producing oil and natural gas from otherwise tight and ultra-low permeable shale formations have led to spurt in exploration activities across the world. As shales are the most abundant lithology in the sedimentary basins, it is natural that exploration should focus on this one of the most important unconventional resource expected to be available over vast areas unlike the conventional hydrocarbons which are found in the relatively smaller and limited areas. This will enable to discover new hydrocarbon fields and the level of 1

12 crude oil and gas production can then be significantly increased in the years to come. It has always been a challenge to maintain a good balance between sustainable development and environmental conservation. The hydrocarbon exploration and development activities are not any exception to this challenge. To mitigate the adverse impacts if any due to the proposed project activity, an impact assessment is carried out in line with the MoEFCC, EIA-2006 notification guidelines. The present report is being submitted for grant of Environmental Clearance for drilling of two shale gas and oil exploratory wells in the on-land Suryaraopeta and Mahadevapatnam PML blocks in the West Godavari district of Andhra Pradesh. The drilling of these wells will provide leads to the further exploration and development of shale gas in the region which is essentially driven by the need for greater energy security of India. This report comprises of baseline data on ambient air quality status, noise levels, surface and ground water quality, soil quality studies with a brief on biological & socio economic status. In addition, methodology followed for preparation of this report and process descriptions of exploratory drilling have also been discussed. The report also documents anticipated environmental impacts, evaluation and mitigation measures based on baseline data collected during study period. The environmental management plan of exploratory drilling activities has also been delineated in the report based on impact evaluation and regulatory requirements. In Krishna-Godavari basin the natural processes in fluvio-marine environments carve out landforms, which are dynamic but always keep attaining equilibrium. These landforms of the basin are modified unless buried by continued fluvial processes. Such paleo-beach ridges can be seen near Amalapuram of Godavari delta. The fluvial plains are a composite of many landforms like natural levees, point bars, channel bars, abandoned channels, meander cutoffs and flood pains. The fluvial plain is constructed by three major rivers of Gautami, Vasistha and Vainatyam. The fluvial plain of Krishna river system showed south westward migration of the drainage through Hamsala Deevi. Presently, this form is a distributary of Krishna River with major drainage to the south of Avanigadda. The 2

13 overall slope of the Godavari delta is gentle towards coast. The Inter deltaic plain occupies the area between two river systems. ONGC s exploration activities are confined 39 on land PML blocks in the Krishna Godavari Basin. These blocks spread across East Godavari, West Godavari and Krishna Districts of Andhra Pradesh. Under the present proposal, Environment Clearance is sought for drilling two shale gas and oil exploratory wells in Suryaraopeta and Mahadevapatnam PML blocks in West Godavari District, Andhra Pradesh. The estimated cost for drilling of these two wells will be Rs. 93 Crores. The baseline data provide the foundation for Environment Impact Assessment (EIA) studies as these will help to identify site-specific impacts on various components of environment. The baseline status also helps relate the effects of the project activities on the environmental components and allows the identification of the parameters that need to be monitored. The baseline information regarding ambient air quality, noise, micro meteorology, characteristics of surface and ground waters and soil quality has been collected directly through field measurements from the villages: Unikili, Andaluru, Kalla and Kolanapalli situated proximity to the proposed exploratory drilling locations. The biological and socio-economic information has been obtained from the secondary sources such as published reports/papers. The regional meteorological data is obtained from the IMD Centre, Hyderabad. Ambient air quality is monitored in the villages of upwind and downwind directions of the proposed locations. The samples were analyzed for SO2, NOx, PM10, PM2.5, CO, hydrocarbons, Ozone, Lead, Ammonia, Benzene and Benzo-pyrene etc. The 24hr average value of ambient air quality in respect of the above parameters were monitored. The values of the critical ambient air quality parameters are as given below PM10: µg/m 3,PM2.5: µg/m 3, SO2: µg/m 3, NOX: µg/m 3,Ozone: µg/m 3,CO: mg/m 3, Ammonia: µg/m 3 and Benzene: µg/m 3. It is observed that all the quality parameters are within the prescribed CPCB limits at the proposed locations. Portable meteorological stations were set up to monitor site specific weather data. Wind roses were drawn on the basis of the collected data for 24 hrs. The winds recorded were predominantly from SW closely followed by SE and calm conditions prevailed for 8-3

14 10 % of the total time. At locations SU-SG-A, MA-SG-A the maximum wind speed is 3.58 m/s and dominant wind direction is S-W. Ambient noise levels were also monitored near the villages of the proposed locations are in the range of db(a) and db(a) during day time and night time respectively. Ground water and surface water samples were collected from the nearby villages close to the proposed locations for the baseline quality assessment. The important parameters tested include ph: , TDS: mg/l, TSS:5-30 mg/l, Chlorides: mg/l, Total hardness: mg/l, Suphates: mg/l. Most of the heavy metals are below detectable levels. Physico-Chemical characteristics of the soils analysed are as follows: ph; , Organic carbon: %, Nitrogen: kg/ha, Phosporous:58-80 kg/ha, Potassium: mg/kg, SAR: The air emissions are mainly from operating DG sets. The air impact prediction has been carried out for DG set stack emissions using standard models. The predicted maximum GLC values of common pollutants like PM, SO2, NOX, CO are well within the regulatory standards. Approximately MT of drill cuttings are generated for each well during the drilling. The water based mud system (WBM) drill cuttings are non-toxic and non-hazardous, will be collected in HDPE impervious lined pits at the site. After completion of drilling these pits will be covered with native top soil. The waste water generated during the operations is also collected in lined waste pits and recycled/reused after treatment with mobile ETP. There is no discharge of any waste water outside from the drill site. Approximately 0.5 MT of spent oil is generated during drilling of each well is collected in drums. The spent oil and used batteries will be sent to base stores for further disposal through authorized recyclers. This report examines environmental and socio-economic impacts of the proposed activity. The impact on community health due to the proposed drilling activities will be negligible but at the same time social status will improve due to increase in employment opportunities etc. There will be positive impact on transportation, communication in the region. 4

15 All the environmental parameters of air, noise, waste water, drill cuttings will be monitored during the drilling at the project site. Surface and ground waters quality will also be monitored at the nearby villages to assess any adverse impacts of the activity. The analysis reports will be regularly submitted to the regulatory authorities: MoEFCC and APPCB along with six monthly EC compliance reports. All the inherent risks associated with the drilling activity have been assessed in detail in the present report by using risk assessment criteria. Existing risk control measures have been studied and additional measures have been proposed in the report for all the risks having high risk. The Environmental Management Plan of ONGC provides a delivery mechanism to address potential adverse impacts if any. ONGC adopts international best practices in its operations. The EMP has been developed into a stand-alone system covering each stage of the drilling activity viz. site preparation, emissions from DG sets, disposal of unused mud, cuttings, recycling and re-use of waste water, site restoration etc. These shale gas assessment wells will provide leads for initiating further exploration programs for the exploitation of huge potential of shale gas resources for ensuring energy security of the country. Every step we take to increase domestic production is an equal step away from dependence on hydrocarbon imports. Conducting shale gas exploration is enlightening us more about our natural resources where they re located and potential ease or difficulty associated with retrieving those resources. Shale gas is transformative and can play a major role towards achieving energy security, economic prosperity and a cleaner environment. Because natural gas has the lowest carbon content of all fossil fuels and not a mixture of other carbon containing compounds with other inorganic impurities, it is the cleanest burning fossil fuel, including lower emissions of sulphur, metal compounds, and carbon dioxide. According to a study conducted by IHS Global Insight, shale gas exploration and production are already providing broad economic benefits. And those benefits are expected to increase dramatically over the next 20 years. 5

16 Chapter-1 Introduction 1.1 Present Exploration Scenario in Krishna-Godavari Basin ONGC has been operating in Krishna-Godavari Basin for the past more than 35 years. The operational areas in KG On-land cover sq.km. This is a unique Basin where the hydrocarbons are discovered in the geologically oldest (250 Million years) to the youngest (5 Million years) sedimentary sequences. The overall success ratio is 1:2.5. These exploratory efforts led to the discovery of 65 small-tomedium sized hydrocarbon fields with about 356 MMT (Oil & Oil Equivalent Gas) of initial in-place on-land reserves as on The current production of Oil and Gas is TPD & MMSCMD respectively, from various facilities located in this area. The KG basin holds ample promise for additional reserve accretion and the Petroleum Ministry is keen on continuing the exploratory activity. 1.2 Shale gas Presence of natural gas in the shale which are source to hydrocarbon found in conventional sand stone and carbonate reservoirs has been well known for a long time in number of sedimentary basins. However, it is only in the past few years that shale as significant source of oil and gas has drawn the attention of explorers. Recent success in USA and Canada in commercially producing oil and natural gas from otherwise tight and ultra-low permeable shale formations have led to spurt in exploration activities across the world. As shales are the most abundant lithology in the sedimentary basins, it is natural that exploration should focus on this one of the most important unconventional resource expected to be available over vast areas unlike the conventional hydrocarbons which are found in the relatively smaller and limited areas. 6

17 Realizing the importance of shale gas and also shale oil for meeting the energy demands of the country and the need to expedite exploration and assessment of Indian shales, Government of India announced policy guidelines on 14 th, October, 2013 allowing national oil companies, ONGC and OIL to take up shale gas and oil exploration activities in their nomination blocks. ONGC was mandated to identify a minimum of 50 nomination blocks where it will take up shale gas and oil exploration in Phase-I. As per the policy, ONGC will have to drill at least one well (two in blocks having an area of more than 200 sq. km.) for assessment of shale gas and oil in each of these blocks in next three years. The policy also stipulates guidelines regarding the environmental clearance, water sourcing and management for shale gas & oil activities. It is outlined in the policy document that the existing guidelines issued from MoEFCC are to be followed for carrying out base line EIA studies. ONGC has a commitment to collect data and drill at least one well in each of the identified blocks in Phase-I, which will expire in March, It is important at this point to mention that an assessment well for shale gas and oil is not different from a typical conventional exploratory well in the sense that initial shale gas wells are primarily vertical like any other conventional exploratory well. In terms of the target depth, casing policy, water consumption, drilling, testing and completion plan, the two types of wells are nearly identical. The shale cores collected from these wells are used to assess the potential of the shale gas and oil in the sedimentary formations. Table-1.1 Co-ordinates of the proposed PML blocks for shale gas drilling: Name of the PML Block Suryaraopeta Mahadevapatnam Latitude Longitude Remarks

18 1.3 Drilling of shale gas/ oil well vis-a-vis normal exploratory wells In contrast to typical shale gas and oil production wells being drilled in North America and other parts of world which require long horizontal sections and multistage hydro-fracturing, the proposed shale gas and oil assessment wells are primarily vertical wells and testing / completion will be subject to positive results from the analysis and evaluation of data collected in individual wells. In all the aspects related to well depth, construction, casing policy, drilling mud chemistry, cementation, testing and completion plan, the proposed assessment wells for shale gas /oil wells are exactly similar to conventional exploratory wells. The main objective of present shale gas / oil wells is to collect conventional cores from the shale formations and record some advanced log suits for proper evaluation of various properties (geochemical, geological, petro physical, mineralogical and geomechanical etc.). Based on these parameters, an estimate of the shale gas and oil in-place will be made. Based on the evaluation of core / cutting samples and log data collected in these assessment wells, prospective zones in the source rock shale formation will be identified and a decision on the testing of such identified zones will be taken. Shale being relatively tight in comparison to conventional sand/ carbonate reservoirs, in general, have very low permeability and are not likely to flow hydrocarbon without hydro-fracturing. However, it is very important to note that at this stage only single zone will be taken for hydro-fracturing unlike complex and extensive multistage hydro-fracturing operation in a typical shale gas well which require excessively large quantity of fresh water and chemicals. The water requirement for hydro-fracturing in the proposed assessment wells will be M 3 per zone per well. This water will be collected in the HDPE lined pit and recycled and reused after treating through mobile ETP. 1.4 Project details ONGC has identified two prospective PML blocks: Suryaraopeta and Mahadevapatnam based on geochemical characteristics of shales for the drilling of two shale gas/oil exploratory wells in West Godavari district, Krishna-Godavari Basin, Andhra Pradesh. Coordinates of these blocks are given in the Table no: 1.1. Details of these two proposed locations for shale gas/oil exploratory drilling are 8

19 given in Table No: 1.2 and map is shown in Fig: 1.1. Gist of the project details are given in Table No Table-1.2: Details of the proposed shale gas/oil exploratory locations Sl. No Name of the PML Block Proposed location Mandal/Village Location coordinates TD (m) Estimat ed cost (Rs.Cr ) 1 Suryaraopeta SU-SG-A Kalla /Kolanapalli Mahadevapatn am MA-SG-A Veeravasaram/ Andaluru Table-1.3: Project details Sl No. Elements Details 1 No. of wells proposed Two 2 Target depths (m) Cost of the project Rs crores) 93 4 Land required/well 5-6 acres 5 Time requred for drilling 3-4 months (Normal conditions) 6 Sensitive areas No sensitive/forest areas near the blocks. Fig-1.1: Map showing proposed locations for shale gas/oil exploratory drilling 9

20 1.5 Objective and scope of the study The purpose of the EIA report is to address the information on the nature and extent of potential environmental impacts during drilling of well and related activities taking place concurrently. The Environment Impact Assessment (EIA) report is prepared on the basis of the existing background pollution levels and address some of the basic factors mentioned below: To assess the existing status of air, noise, water, land, biological and socioeconomic components of environment. To identify and quantify significant impacts of proposed exploratory drilling on various environmental components. To evaluate the proposed pollution prevention and control measures. To prepare an Environmental Management Plan (EMP) outlining control technologies and or practices to be adopted for mitigation of adverse impacts. To delineate post-project environmental quality monitoring program to be pursued. In order to assess the possible impacts of shale gas exploratory drilling and to generate baseline data on the air, water, land, biological and socio-economic environments. Present report has been prepared based on data collected from ONGC s respective operational areas from Krishna Godavari basin and also based on studies conducted by following resource agencies. Care Labs, Hyderabad, recognized by Ministry of Environment, Forests and Climate change, Govt. of India. Indian Meteorological Department, Govt. of India, Hyderabad The data related to flora-fauna and social economic have been taken from secondary resources and published literature. In this report the data have been presented along with the anticipated likely impacts, and mitigation measures. Accordingly environmental management plan has been prepared and documented. Risks of the project have been identified and ERP and DMP has been detailed in the chapter Risk identification and risk control measures. 1.6 Project Benefits: These shale gas assessment wells will provide leads for initiating further exploration programs for the exploitation of huge potential of shale gas resources for ensuring 10

21 energy security of the country. Every step we take to increase domestic production is an equal step away from dependence on hydrocarbon imports. Conducting shale gas exploration is enlightening us more about our natural resources where they re located and potential ease or difficulty associated with retrieving those resources. Shale gas is transformative and can play a major role towards achieving energy security, economic prosperity and a cleaner environment. This will also buy time while renewable energy develops into an economically reliable source of energy. Because natural gas has the lowest carbon content of all fossil fuels and not a mixture of other carbon containing compounds with other inorganic impurities, it is the cleanest burning fossil fuel, including lower emissions of sulphur, metal compounds, and carbon dioxide. According to a study conducted by IHS Global Insight, shale gas exploration and production are already providing broad economic benefits. And those benefits are expected to increase dramatically over the next 20 years. 11

22 Chapter-2 Drilling Technology and Process Description 2.1 Drilling process Drilling operation is carried out using an electrically operated rig. A sketch of typical oil & gas drilling Rig is shown in Fig Drilling unit for drilling of oil and gas wells consists of a derrick at the top of which is mounted a crown block and a hoisting block with a hook. From the swivel is suspended a Kelly stem which passes through a square or hexagonal Kelly Bush which fits into the rotary table. The rotary Table receives the power to drive it from an electric motor. The electric motor rotates the rotary table, through which passes the Kelly bush, and the rotations are transmitted to the bit as the drilling progresses, the drill pipes in singles are added to continue the drilling process. At the end of the bit life, the drill pipes are pulled out in stands and stacked on the derrick platform. A stand normally has three single drill pipes. After changing the bit, the drill string is run back into the hole and further drilling is continued. This process continues till the target depth is reached. During the course of drilling, cuttings are generated due to crushing action of the bit. These cuttings are removed by flushing the well with mud pumps. The mud from the pump discharge through the rotary hose connected to stationary part of the swivel, drill string and bit nozzles. The mud coming out of the bit nozzles pushes the cuttings up the hole and transports them to the surface through the annular space between the drill string and the hole. The mud not only carries away crushed rock from the bottom of the hole but it also cools the bit as it gets heated due to friction with formation while rotating. The hydrostatic head of the mud helps in balancing subsurface formation pressures thereby preventing uncontrolled flow of formation fluids into the well bore in extreme cases this phenomenon is termed blow-out, a rare occurrence. 12

23 At the surface, the mud coming out from well along with the cuttings falls in a trough, passes through the solids control equipment i.e. shale shaker, de-sander/ de-silter and mud cleaner. These equipment remove the solids of different sizes, which get mixed with the mud during the course of drilling. The cleaned mud flows back to the suction tanks to be pumped again into the well. The drilling mud/fluid circulation is thus a continuous cyclic operation. A schematic diagram of the drilling mud circulatory system is shown in Fig.2.2. Fig-2.1: Typical on-land Drilling Rig 13

24 Fig- 2.2: Schematic Drilling Fluid Circulation The most suitable clay for mud preparation is Bentonite, which is capable of forming highly dispersed colloidal suspensions. Various other chemicals are also used in mud preparation as per requirements dictated by the temperature/pressure conditions of the wells. The mud is continuously tested for its properties such as density, viscosity, yield point, water loss, ph value etc. to ensure that the drilling operations can be sustained without any down-hole complications. 2.2 Drilling Facilities 14

25 Drilling is a temporary activity, which will continue from 3 to 4 months for each well drilled in the block under normal conditions. However, this depends upon depth of well to be drilled. The rigs are self-contained for all routine jobs. Once the drilling operations are completed, based on the evaluation of core/ cutting samples and log data collected in these assessment wells, prospective zones in the source rock shale formation will be identified for hydro-fracturing and production testing Drill site Approximately 130mx130m area of land is acquired for placing rig and associated facilities such as mud tanks, diesel tanks, water tank, generators, PCR, mud pumps and material storage facilities as shown in Fig 2.3. Fig -2.3: Typical Drill Site Layout Plan Drilling Mud Drilling of wells requires specially formulated muds (drilling fluid) which basically comprise in earth materials like bentonite, barite in water with several additives to 15

26 give mud weight, fluidity and filter cake characteristics while drilling. The drilling muds have several functions like lubrication and cooling of the drill bit, balancing subsurface formation, bringing out the drill cuttings from the well bore, thixotropic property to hold cuttings during non-operations, formation of thin cake to prevent liquid loss along well bore etc. Several additives are mixed into the mud system to give the required properties. Water based mud will be used to the possible extent in exploratory drilling but use of synthetic oil based mud (SOBM) may require due to complexities associated with the geological formation and associated hole stability problems. The constituents of water based mud (WBM) are as follows: Barite Carboxyl Methyl Cellulose Bentonite Mud Thinner/Conditioner Resinated Lignite Non-Weighted Spotting Fluid Weighted Spotting Fluid EP Lube Drilling Detergent Caustic Soda Potassium Chloride Soda Ash The special additives and their functions in WBM are shown Table-2.1 below: Table-2.1: Special additives and their functions in the mud Sr. No Additives Functions 1 Sodium bicarbonate Eliminate excess calcium ions due to cement contamination 2 Sodium Chloride Minimize borehole washout in salt zones 3 Groundnut shells, & mica Minimize loss of drilling mud to flakes formation 4 Cellulose polymers or starch To decrease filter loss and to form thin filter cake 5 Aluminum stearate Minimize foaming 6 Vegetable Oil lubricant Reduce torque and drag on drill string. 7 Counter differential pressure sticking of Pill of oil-based mud spotting drilling string. Pill is placed down hole fluid opposite contact zone to free pipe. 16

27 2.2.3 Power requirement The drilling process requires movement of drill bit through the draw works, which require power. The power requirement of the drilling rig is met by using the Diesel Generator sets in the drill site. The drilling rig requires from 3-4nos. of 8 KVA D.G sets (AC-SCR Type.) with a peak diesel consumption of about 3-4 KLD, whereas during testing and other operations, the diesel consumption is about KLD. The exhaust stacks of the DG sets of land based rigs vent the emissions at an approximate height of 4-5 m from the ground level. Fig -2.4: Power Generator Set at the Drilling Rig Water Requirement The water requirement in a drilling rig is mainly meant for preparation of drilling mud apart from washings and domestic use. While the former consumes the majority of water requirement, the water requirement for domestic and wash use is very less. The daily water consumption will be 25 m 3 /d of which 15 m 3 /d will be used for mud preparation and 10 m 3 /d will be used for domestic purposes including drinking. The total quantity of water requirement is about m 3 which shall be transported 17

28 from nearby sources through a tanker after due approvals. Effluent water is recycled after treatment using mobile ETP and reused for cleaning of derrick floor etc Solids Removal Equipment The rock cuttings and fragments of shale, sand and silt associated with the return drilling fluid during drilling are separated using linear motion shale shakers and other solids removal equipment like de-sanders and de-silters (Fig- 2.5). The recovered mud is reused while the rejected solids are collected and disposed of in a HDPE lined waste pit in the drill site. Shale shaker Fig-2.5:Solids Removal Equipment Chemical and other storage facilities The drilling rigs have well maintained storage facilities for fuel oil, required chemicals and the necessary tubular & equipment. The storage places are clearly marked with safe handling instructions Manpower The drilling rig is manned by about 30 persons at any time. The manpower operates in two 12-hour shifts with continuous operations on the rig. DSA is provided near the drill site for living accommodation of the crew Logistics Crew transfers to and from the drilling rig, materials, diesel and chemicals is done using light vehicles, trucks and trailers Drill cuttings and waste residual mud 18

29 During drilling operations, approx T/day of wet drill cuttings are expected to be generated from the well depending on the type of formation, hole size and rate of drilling. Quantity of wet drill cuttings expected to be generated for various hole sizes is given in Table no In addition to the drill cuttings, about m 3 /day of wastewater is likely to be generated during well drilling. The waste residual mud, washed drill cuttings (components of clay, sand etc.) and waste water are collected in the HDPE lined waste pit as shown in Fig-2.6. Table-2.2: Quantity of drill cuttings generated Sl. No Hole diameter (Inches) Drilled depth (M) Qty. of cuttings (M 3 ) Figure 2.3 Fig-2.6: HDPE lined waste pit 2.4 Domestic Wastewater The operating personnel in onshore drilling site accommodation (DSA) in the vicinity of the location consume fresh water for drinking and sanitation purpose. Septic tanks and soak pits are normally provided to dispose off the domestic wastewater in the base camps. 19

30 2.5 Hydro Fracturing An over view Shale unlike conventional sandstone/ carbonate reservoirs are very tight in nature with ultra-low permeability and will need to be stimulated (normally through hydrofracturing) for getting the production of hydrocarbons from them. Hydraulic fracturing has been, and will remain, one of the primary engineering tools for improving well productivity. This is achieved by Creating a conductive channel through near wellbore Extending the channel to a significant depth into the reservoir to further increase productivity Placing the channel such that fluid flow in the reservoir is altered. Initially, fracture penetration is limited, and hence fluid loss is high near the wellbore. For that reason, the first part of a hydraulic fracture treatment consists of fluid only (no proppant); this is termed as pad. The purpose of a pad is to break down the wellbore and initiate the fracture. Also, the pad provides fluid to produce sufficient penetration and width to allow proppant-laden fluid stages to later enter the fracture and thus avoid high fluid loss near the fracture tip. After the pad, proppant-laden stages are pumped to transport propping agent into the fracture. However, because fluid loss to the formation is still occurring, even near the well, the first proppant is added to the fluid at low concentrations. The proppant-laden slurry enters the fracture at the well and flows toward the fracture tip. At this point, two phenomena begin. First, because of the higher fluid loss at the fracture tip, slurry flows through the fracture faster than the tip propagates, and the proppant-laden slurry eventually overtakes the fracture tip. Next, because of fluid loss, the proppant-laden slurry stages lose fluid (but not proppant) to the formation. Thus, proppant concentration (i.e., volume fraction of solid proppant) increases as the slurry stages dehydrate. As the proppant slurry stages move down the fracture, they dehydrate and concentrate. Slurry stages pumped later in the treatment are pumped at a higher concentration. 20

31 The preceding description might be termed a normal design, where the entire fracture is filled with a uniform, preselected, and design proppant concentration just as the treatment ends. If pumping continues past that point, there would be little additional fracture extension because the pad is 100% depleted. Continued pumping forces the fracture to become wider (and forces the pressure to increase) because the increased volume simply acts like blowing up a balloon. In some cases the additional propped width that results may be desirable, and this procedure is used purposely. This is termed tip-screen out (TSO) fracturing. At the conclusion of the treatment, the final flush stage is pumped. This segment of a treatment consists of one wellbore volume of fluid only and is intended to sweep the wellbore clean of proppant. The well is generally then shut-in for some period to allow fluid to leak off such that the fracture closes on and stresses the proppant pack. Shut-in also allows temperature (and chemical breakers added to the fluid while pumping) to reduce the viscosity of the fracturing fluid. After the job is complete, the flow back is taken immediately (forced closure) or after a few hours (4-6 hours) depending on the reservoir characteristics, temperature, fracturing fluid formulations, gel breaking time etc. The typical fracturing fluid composition and activity of Hydro Fracturing (HF) job are given in the Table-2.3 and Fig- 2.7 respectively: Table-2.3: Typical composition of fracturing fluids Sl.No. Name of Chemical Concentration (%v/v) 1 Potassium Chloride 2 2 Biocide Acetic acid Sodium thiosulphate Gelling Agent-II (Guar APS Non Emulsifiers Surfactant Soda Ash Borax

32 Fig-2.7: Hydro fracturing activity Water treatment & disposal of the flow back water: The flow back from the well after hydro-fracturing job, will be regularly monitored and due care/ treatment will be carried out for safe disposal as per the MoEFCC and Pollution Control Board guidelines in this regard. 2.6 Production testing Production testing for the exploratory drilling of the well is only for short duration (2-3 days). Flare pit is constructed near the site for flaring of gases during production testing. Discharge of gaseous emissions during production testing is only for short period. The residual oily wastes if any after completion of testing phase are completely removed and sent to the authorized waste disposal site or oil handling installations for resource conservation. 2.7 Site Restoration After completion of drilling and dismantling of the rig all the equipment and waste materials from the site are removed and transported. The waste residual mud and drill cuttings collected in the HDPE lined waste pit are allowed to dry and covered with native top soil. The site is restored as near as possible to the original state as per the approved restoration procedure of ONGC. 22

33 Chapter-3 Baseline Environmental Quality Status Baseline environmental status in and around proposed locations depicts the existing environmental conditions of air, noise, water, soil, biological and socio-economic environments. It serves as the basis for identification, prediction and evaluation of impacts. The baseline environmental quality for the proposed exploratory drilling locations have been assessed for the following environmental components, which are most likely to be influenced by the drilling activity: Ambient Air Quality Meteorological conditions Noise levels Water quality (Surface +Ground water) Soil quality Biological and Socio-economic studies. The primary baseline environmental quality for the rapid EIA is assessed through field studies within the impact zone for various components of the environment, viz. air, noise, water, Soil and socio-economic. Meteorological data has been obtained from Indian Meteorological Department, Govt. of India, Hyderabad. Other data has been collected from various published reports and papers. 3.1 Topography: The topographic maps (1:30000) of the proposed locations are given in Fig-3.1. All the sites of the proposed locations are mostly in agricultural fields having main crops like paddy and coconut with substantial activity of aquaculture. There are no wild life sanctuaries or eco-sensitive zones within 10 km radius of the proposed locations. 23

34 Fig-3.1: Topographic maps of the proposed locations 24

35 3.2 Baseline Environmental Quality: Sampling stations: Baseline environmental quality in the nearby villages: Unnikili, Andaluru, Kalla and Kolanupalli proximity to the proposed locations were monitored during the period from to by establishing the sampling network as per the standard guidelines. Air monitoring stations were set up at each location at the upwind and downwind directions of the nearest villages adjoining the proposed locations. Samples of 24 hourly averages were collected for air pollutants. Surface and sub-surface water samples were collected from the fresh water ponds and bore wells of the nearby villages. The ponds were mostly fed by the river canals. Noise level measurements were carried out in the nearby villages using the portable noise level recorder. Soil samples were also collected and analyzed for the characterization of soils near the proposed locations. The sampling stations and the proposed locations are shown in the Fig-3.2. Fig.3.2: Map showing sampling stations along with proposed drilling locations in PML blocks 25

36 3.2.1 Ambient Air Quality: High volume air samplers (Ecotech PM2.5/PM10 sampler Models: AAS-127/11-I-110 and AAS-127/11-J-07) were used for the sampling of suspended particulate matter and common air pollutants, viz. NOx and SO2 using Whatman glass fiber filters. Standard spectrophotometric methods of analysis were employed for determination of NOx and SO2. Air quality data at all the sampling stations are given in the Table nos: 3.1 to 3.2. At each location, sampling was carried for the parameters: PM2.5, PM10, SO2, NOx, Benzene, Benzo pyrene (VOC), Methane, Ammonia and nonmethane hydrocarbons. Summary of the critical parameters observed are given in the Table no Meteorological scenario of the study area: The study of meteorological conditions forms an intrinsic part of the Environment Impact Assessment study. The meteorological conditions of an area and the industrial process are both intertwined and each has a definite influence over the other. Dispersion of different air pollutants released into the atmosphere has significant impacts on neighborhood air environment. The dispersion/dilution of the released pollutant over a large area will result in considerable reduction of the concentration of a pollutant. The dispersion in turn depends on the weather conditions like the wind speed, direction, temperature, relative humidity, mixing height, cloud cover and also the rainfall in the area. It also helps in determining the sampling stations in predicting the post project environmental scenario. The micrometeorological data has been obtained by installing a portable wind monitoring instrument (Rainwiseinc WS-2000/MK111 Edition) at each air monitoring station. Sensors were fixed on roof top of the buildings in the villages for measuring the wind direction, speed, air temperature and relative humidity. The data were recorded using data logger. The monitored weather data at the proposed locations is given in the table nos: Based on the meteorological data, wind roses diagrams for the specific site-that is the pictorial representation of wind speed and wind direction along with their persistence for a fractional period of occurrence at a given location is constructed. The winds recorded were predominantly from SW 26

37 closely followed by SE and calm conditions prevailed for 8-10 % of the total time. At locations SU-SG-A, MA-SG-A the maximum wind speed is 3.58 m/s and dominant wind direction is S-W. Climatology: The climate of the study area is moderate both in winter and summer seasons in the delta area. In the non-delta area, the heat in the summer is severe especially in the tracts of upland and agency areas. The climate of the area of the proposed locations is classified as warm, humid and tropical. Temperature: The maximum temperature recorded is 98.0 o F (36.6 o C) and minimum is 75 o F (23.8 o C). The maximum temperature is usually recorded in the months of April and May. Humidity: Humidity is very high and rises to about 100% during south west monsoon minimum recorded is 49%. Rainfall: The rain fall during the study period is 0%. South-West and North-East monsoons are the two important periodic winds, which are the important sources of the rain. Fig-3.3: Wind rose diagrams of the proposed locations 27

38 Sl. No. Table-3.1: Ambient Air Quality data at location: SU-SG-A Parameters/ Name of the Habitat Kalla Up-Wind Results Kalanapalli Down- Wind Table-3.2: Ambient Air Quality data at location: MA-SG-A Kalla (S Side) CPCB s NAAQ Standards Value is (<) 1. Particulate Matter (PM2.5), µg/m Particulate Matter (PM10), µg/m Sulphur Dioxide (SO2), µg/m Oxides Of Nitrogen (NOx), µg/m Ozone (O3), µg/m 3 (8hrs) Lead (Pb), µg/m Carbon Monoxide, mg/m 3 (8hrs) Ammonia (NH3), µg/m Benzene (C6H6), µg/m Benzo(a)Pyrene, ng/m 3, DL(<0.1) BDL BDL BDL Hydrocarbons, ppm, DL(0.05) BDL BDL BDL Non Methane HC, ppm, DL(0.01) BDL BDL BDL Hydrogen Sulphide, ppm, DL(<5) BDL BDL BDL Mercury (Hg),ng/m 3, DL(<2) BDL BDL BDL Arsenic (As), ng/m 3, DL(<2) BDL BDL BDL Nickel (Ni), ng/m 3, DL(<2) BDL BDL BDL 20 Sl. No. Parameters/ Name of the Habitat Andaluru Up-Wind (South Side) Results Unikili Down-Wind (North Side) CPCB s NAAQ Standards Value is (<) 1. Particulate Matter (PM2.5), µg/m Particulate Matter (PM10), µg/m Sulphur Dioxide (SO2), µg/m Oxides Of Nitrogen (NOx), µg/m Ozone (O3), µg/m 3 (8hrs) Lead (Pb), µg/m 3 DL(0.01) BDL BDL Carbon Monoxide (CO), mg/m 3 (8hrs) Ammonia (NH3), µg/m Benzene (C6H6), µg/m Benzo Pyrene, ng/m 3, DL(<0.1) BDL BDL Hydrocarbons, ppm, DL(0.05) BDL BDL Non Methane HC, ppm, DL(0.01) BDL BDL Hydrogen Sulphide, ppm, DL(<5) BDL BDL Mercury (Hg),ng/m 3, DL(<2) BDL BDL Arsenic (As), ng/m 3, DL(<2) BDL BDL Nickel (Ni), ng/m 3, DL(<2) BDL BDL 20 28

39 Table-3.3: Summary of the Air Quality parameters Sl.No. Parameters Value range CPCB s NAAQ Standards Value is (less than) 1. Particulate Matter (PM2.5), µg/m Particulate Matter (PM10), µg/m Sulphur Dioxide (SO2), µg/m Oxides Of Nitrogen (NOx), µg/m Ozone (O3), µg/m 3 (8hrs) Lead (Pb), µg/m 3, DL(0.01) BDL Carbon Monoxide (CO), mg/m 3 (8hrs) Ammonia (NH3), µg/m Benzene (C6H6), µg/m

40 Table-3.4: Micro meteorological Conditions at Location: SU-SG-A Time 0 Tem F chill F Dew F Heat F 0 Hum % RH Press InHg Rain In Dir 0 Speed mph 00Pm : : : : : : : :00Am : : :30AM : ; : : : : : ; : : : : : : : : : : : ; : : : : : ; : : ; : : : ; ; : : Maximum Minimum

41 Table-3.5 Micro meteorological Conditions at Location: MA-SG-A Time 0 Tem F Chill F Dew F Heat F 0 Hum % RH Press InHg Rain In Dir 0 Speed mph 17:30PM : : : : : : : : : : :00AM : ; : : : : : ; : : : : : : : : : : : ; : : : : : ; : : ; : : : ; ; : : Maximum Minimum

42 Regional Meteorological Scenario Andhra Pradesh state being in tropical climate region, there are three climatic seasons: based on the general weather conditions: Summer season : March to May Rainy season : June to September Winter season : October to February The rainfall in Andhra Pradesh is influenced by both South-West and North-East Monsoons. The normal annual average rainfall of the State is 940 mm. Major portion (68.5%) of rainfall is contributed by South-West Monsoon (June-Sept) followed by (22.3%) North-East Monsoon (Oct-Dec). The rest 9.2% of the rainfall is received during the remaining part of the year. Weather data obtained for the period April 2015 to March 2016 from the Indian Meteorological Department (IMD) regional weather station located at Narsapuram in West Godavari district of Andhra Pradesh is shown in the Table-3.6. The data collected at these stations indicate the annual rainfall fall is 1528 mm at Narsapuram. Temperatures: The maximum/minimum temperatures recorded are 36.7/20.6 Narasapuram. Wind data: The monthly maximum/minimum average wind speeds recorded are 0.56/0.28 m/s at Narasapuram. Humidity: The monthly average humidity values recorded during morning and evening times at Narasapuram are 64 to 88%. 32

43 Table-3.6: Monthly average weather parameters at Narasapuram IMD station NARSAPURAM-WEST GODAVARI DISTRICT Temperature Total Rain RH AWS Month Max ( o C) mm mm (%) (%) (m/s) Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Noise Environment Noise can be defined as unwanted sound or any sound that is undesirable because it interferes with speech and hearing, is intense enough to damage hearing or is otherwise annoying. From the noise source, natural or man-made barriers between the source and the impacted population, weather conditions which could potentially absorb, reflect, or focus sound (such as wind speed, direction, temperature inversions), and the scale of industrial activity. The environmental impact of noise can vary from noise induced hearing loss (NIHL) to annoyance depending on the loudness of noise levels and tolerance levels of individual. The objective of noise monitoring survey in and around the proposed project site is to identify the existing noise sources so as to measure background noise levels and to suggest mitigation measures to alleviate adverse impact of noise. Noise monitoring was carried out by Lutron noise recorder, Model: SL-4001/ to identify and quantify the ambient condition to predict the increase in noise levels and causes of variability of noise levels as a result of the proposed project. The noise levels recorded in the villages: Unnikili, Andaluru, Kalla and Kolanupalli near the proposed locations (baseline data) have been collected and given in Table Nos: The summary of noise levels recorded are also given in the table no

44 Table- 3.7 Noise level survey at proposed location: MA-SG-A Sl.N Time UNIKILI ANDALURU o. db (A) db(a) 1. 13: : : : : : : : : : : : : : : : : : : : : :

45 Table-3.8: Noise level survey at proposed location: SU-SG-A Sl.No. Time Kalla Kolanapalli db (A) db (A) 1. 13: : : : : : : : : : : : : : : : : : : : : : : : Table-3.9: Summary of the noise levels in the villages near the proposed locations Sl.No. Location Day time ( ) Night Time ( ) db (A) db(a) 1 MA-SG-A SU-SG-A Water Environment Surface water and ground water samples were collected from nearby villages of the proposed locations. Ground water samples are collected from the bore wells (hand pumps) which are normally at a depth of more than 30 ft. Surface waters are collected from nearby ponds or irrigation canals. Physico-chemical parameters have been determined to ascertain the baseline status of the existing groundwater 35

46 and surface water resources. The results are given in Table nos: Summary of the water quality parameters are shown in Table no.3.12 Table-3.10: Baseline Water Quality at the proposed location: MA-SG-A Sl. No Test Parameters Units Andaluru (Ground water) Unikili (Bore well water) 1. ph Turbidity NTU Total Dissolved Solids mg/l Total Suspended Solids mg/l Total Hardness mg/l Calcium as Ca mg/l Magnesium as Mg mg/l Alkalinity to Phenolphthalein as CaCO3 9 Alkalinity to Methyl orange as mg/l NIL NIL mg/l CaCO3 10 Sulphates as SO4 2- mg/l Chlorides as Cl - mg/l Chemical oxygen demand mg/l Biochemical oxygen demand mg/l Sulphide as S 2- mg/l < 0.05 < Phenols mg/l < < Cyanide as CN - mg/l < 0.01 < Iron as Fe mg/l Total Chromium as Cr mg/l < 0.01 < Copper as Cu mg/l Lead as Pb mg/l < 0.01 < Nickel as Ni mg/l < 0.01 < Zinc as Zn mg/l < 0.01 < Mercury as Hg mg/l < < Cadmium as Cd mg/l < 0.01 < Sodium as Na + mg/l Potassium as K mg/l Cobalt as Co mg/l < 0.01 < Barium as Ba mg/l < 0.01 < Manganese as Mn mg/l

47 Table-3.11: Baseline Water Quality at the proposed location: SU-SG-A Sl. No. Test Parameters Units Kalla (Ground water) Kalanapalli (Surface Water) 1. ph Turbidity NTU Total Dissolved Solids mg/l Total Suspended Solids mg/l Total Hardness mg/l Calcium as Ca mg/l Magnesium as Mg mg/l Alkalinity to Phenolphthalein as CaCO3 mg/l NIL NIL 9 Alkalinity to Methyl orange as CaCO3 mg/l Sulphates as SO4 2- mg/l Chlorides as Cl - mg/l Chemical oxygen demand mg/l < 5.0 < Biochemical oxygen demand mg/l < 3.0 < Sulphide as S 2- mg/l < 0.05 < Phenols mg/l < < Cyanide as CN - mg/l < 0.01 < Iron as Fe mg/l Total Chromium as Cr mg/l < 0.01 < Copper as Cu mg/l < 0.01 < Lead as Pb mg/l < 0.01 < Nickel as Ni mg/l < 0.01 < Zinc as Zn mg/l < 0.01 < Mercury as Hg mg/l < < Cadmium as Cd mg/l < 0.01 < Sodium as Na + mg/l Potassium as K mg/l Cobalt as Co mg/l < 0.01 < Barium as Ba mg/l < 0.01 < Manganese as Mn mg/l < 0.01 <

48 Table-3.12: Summary of the water quality parameters Sl.No. Test Parameters Units Ground Surface 1. ph Turbidity NTU Total Dissolved Solids mg/l Total Suspended Solids mg/l Total Hardness mg/l Calcium as Ca mg/l Magnesium as Mg mg/l Sulphates as SO4 2- mg/l Chlorides as Cl - mg/l Chemical oxygen demand mg/l < <5 11 Biochemical oxygen demand mg/l < <3 12 Iron as Fe mg/l Total Chromium as Cr mg/l < 0.01 < Copper as Cu mg/l < 0.01 < Lead as Pb mg/l < 0.01 < Nickel as Ni mg/l < 0.01 < Zinc as Zn mg/l < 0.01 < Mercury as Hg mg/l < < Cadmium as Cd mg/l < 0.01 < Sodium as Na + mg/l Potassium as K mg/l Cobalt as Co mg/l < 0.01 < Barium as Ba mg/l < 0.01 < Manganese as Mn mg/l < < Soil Environment Soil samples were collected at proposed locations during the period from to Sample analysis results are given in the Table nos: and summary is given in Table no

49 Table-3.13: Baseline Soil quality at the proposed location: SU-SG-A RESULTS S.No TEST PARAMETERS UNITS Kalla Kalanapalli 1. ph (1:5 Extraction) Electrical Conductivity µs/cm (1:5 Extraction ) 3. Moisture Content % Organic Carbon % Nitrogen kg/ha Phosphorus as P kg/ha Potassium as K mg/kg Sodium as Na mg/kg Calcium as Ca mg/kg Magnesium as Mg mg/kg Chlorides as Cl mg/kg Sulphates as SO4 mg/kg Organic Matter % Sodium Absorbing Ratio Method of Testing: As per M.L.Jockson and Food & Agriculture Organization Table-3.14: Baseline Soil quality at the proposed location: MA-SG-A RESULTS Sl.No TEST PARAMETERS UNITS Andaluru Unikili 1. ph (1:5 Extraction) Electrical Conductivity µs/cm (1:5 Extraction ) 3. Moisture Content % Organic Carbon % Nitrogen kg/ha Phosphorus as P kg/ha Potassium as K mg/kg Sodium as Na mg/kg Calcium as Ca mg/kg Magnesium as Mg mg/kg Chlorides as Cl mg/kg Sulphates as SO4 mg/kg Organic Matter % Sodium Absorbing Ratio

50 Table-3.15: Summary of soil quality parameters S.No TEST PARAMETERS UNITS Range of Values 1. ph (1:5 Extraction) Electrical Conductivity (1:5 Extraction ) µs/cm Moisture Content % Organic Carbon % Nitrogen kg/ha Phosphorus as P kg/ha Potassium as K mg/kg Sodium as Na mg/kg Calcium as Ca mg/kg Magnesium as Mg mg/kg Chlorides as Cl mg/kg Sulphates as SO4 mg/kg Organic Matter % Sodium Absorbing Ratio Biological Environment Natural flora and fauna are important features of the environment. They are organized into natural communities and are sensitive to outside influences. Integrating ecological thinking into the planning process is an urgent need in the context of deterioration of natural environments, which is unwanted but direct consequence of development. Biological communities, being dependent on the condition and resources of its location may change if there is change in the environment. Hence changes in the status of flora and fauna are an elementary requirement of Environmental Impact Assessment studies. Information on flora and fauna were collected within the study area.(from published secondary data reference state government reports.) Description of Study Area The proposed project of exploratory drilling in on-land blocks are located in West Godavari district of Andhra Pradesh. Study areas mostly comprises of rural villages:, Unikili, Andaluru, Kalla and Kolanupalli, with agricultural land, aqua culture, wasteland and barren land where most of the vegetation is aggregated on agricultural bunds & canals. The study around the proposed site comprises of terrestrial ecosystem which is covered mainly with tropical deciduous vegetation 40

51 characterized by dominance of Terminalia tomentosa, Pterocarpus marsupium, Cassia fistula, Artocarpus integrifolia, Mangifera indica, Dendrocalamus strictus, Albizia lebbeck, Tamarindus indica, Pongamia orientalis, Madhuca indica, Bauhinia racemosa, Bambusa arundinacea etc. Biodiversity of the Study Area The study area consists of dominantly soil system where the irrigation is supported by network of river canals. Consistent with the variety of soils, climate and the past management the study area bears a variety with different species and composition. Essentially all are tropical vegetation identified into various ecological formations. Trees, shrubs and herbs were recorded for measuring plant s importance. Qualitatively, flora can be assessed by delineating the type, its habitat, unique vegetation features and interrelations with other community members. A sizable number of animal species were found to be recorded by the forest department of the area. Apart from barren lands, open grassland, herbs, shrubs, bushes and aquatic impoundments are favorable habitats for the wild animals. Quite apart from their general alertness and quickness of movement, characters in which they are equaled only by birds, mammals possess a varied armory of weapons of offence and defense. Vegetative Composition of the West Godavari district Forest types in West Godavari district include moist deciduous forests confined mostly to Paapi hills, dry deciduous forests in agency tract and thorny forests in upland region. The forest area is more in Polavaram Buttaygudem, Jediugumilli. Shrub type forest appears in Pedavegi, Chintalapudi mandals. The forests in Eluru division are spread over the land mass in Krishna and West Godavari districts that lies between Godavari and Krishna river. The southern half of the land area in this division is coastal plain with vast delta formed by rivers Godavari & Krishna where almost whole area is under agriculture. The forest areas of this division are confined to northern half of the land areas where they generally clothed the hills & hill slopes. Total growing stock is 5.27 million M 3. Of this, 4.81 million M 3 is in Dense Forest, 0.42 million M 3 in Open and 0.04 million M 3 in the Scrub Forest. 41

52 Average growing stock of the division is M 3 /Ha. Canopy class-wise average growing stocks are M 3 /Ha in Dense, M 3 /Ha in Open and M 3 /Ha in Scrub Forest. The 5 species Xylia xylocarpa (1.46), Anogeissus latifolia (0.49), Lannea coromandelica (0.24), Terminalia tomentosa (0.18) and Dalbergia paniculata (0.17) contributing maximum to the Growing Stock in the division. The total number of stems in the division is million. Of these, million fall in Dense, 3.21 million in the Open and 0.20 million in Scrub Forest. Average number of stems per Ha in division is 278. They are in Dense Forest /Ha, in Open Forest /Ha and in Scrub Forest /Ha. Top 5 prominent species in terms of number of stems in the division are Xylia xylocarpa, Anogeisus latifolia, Cleistanthus collinus, Eucalyptus tereticornis and Wrightia tomentosa. Forest types in West Godavari district include moist deciduous forests confined mostly to Paapi hills, dry deciduous forests in agency tract and thorny forests in upland region. The forest area is more in Polavaram Buttaygudem, Jedugumilli. Shrub type forest appears in Pedavegi, Chintalapudi mandals. The forests in Eluru division are spread over the land mass in Krishna and West Godavari districts that lies between Godavari and Krishna river. The southern half of the land area in this division is coastal plain with vast delta formed by rivers Godavari & Krishna where almost whole area is under agriculture. The forest areas of this division are confined to northern half of the land areas where they generally clothed the hills & hill slopes. Major trees and shrubs found in the West Godavari district are Boerhavia diffusa, Evolvulus nummularis, Gomphrina ceosioide, Zizipus mauritiana, Achyranthus aspera, Amaranthus viridis, Tribulus zygophylaceae, Altrnanthera sessilis, Cyanodon species, Manselia minuta, Tamarix species, Cida chordata, Vironia species, Asparagus species, Cleome gynandra, Lantata camera, Adathoda vasica, Heliotropium species, Convolvulus species, Abutilon indicum, Cardiospurmum halicalrum, Cassia species, Cestrum species, Murraya exotica, Commelina benghalensis, Tridex proumbens, Phyllanthus. Palmera plan, Moringa, Mimosops elengi, Grecia hirsute, Typha elephantia, Lotus, Marsilea quadrifolia, Salvinia 42

53 motesta, Pistia stratiotes, Nelumbo nucifera, Trapa natans, Eichhornia crassipis, Calotropis species, Emblica officinalis, Acacia and Delonix regia. Fig-3.4: Forest Distribution in West Godavari District Socio-economic environment and Land use Land cover of the study Area. Reconnaissance The study of socio-economic component of environment is incorporating various facets viz. demographic structure, availability of basic amenities such as housing, education, health and medical services, occupation, water supply, sanitation, communication and power supply, prevailing diseases in the region as well as features such as places at tourist attraction and monuments of archaeological 43

54 importance. The study of these parameters helps in identifying, predicting and evaluating the likely impacts due to project activity in that region. West Godavari: West Godavari district is one of the 13 districts in the Indian state of Andhra Pradesh. The district is situated in Coastal Andhra region of the state. Eluru is the administrative headquarters of the district. As of 2011 census of India, it has an area of 7,742 km 2 (2,989 sq miles) and a population of 3,936,966. It is bounded by Krishna district on the west, East Godavari district on the east, Bay of Bengal on the south and the state of Telangana on the north. Eluru is the biggest city in West Godavari District. It is famous for its thriving woolen pile carpet industry. The district is in the delta region of the Krishna and Godavari rivers. West Godavari is popularly known as the Granary of Andhra Pradesh since about 50 per cent of the state's rice production comes from this district. The district s literacy rate is as per 2011 census which is grown from percent to per cent over the years The district has a progressive sex ratio of Agriculture is one of the main occupation in the district with the main produce being paddy. Sugar cane, cashew nut, mango and coconut. Apart from agriculture the farmers also indulge in aquaculture such as pisiculture and shrimp farming. Wooden pile carpet industry in Eluru produces ecofriendly carpets from wool and are exported to foreign countries as well. 44

55 Fig-3.5: Land use Land cover Map of West Godavari district Base line Socio Economic Status The socio-economic information has been gathered from the nearby villages of the proposed locations in the West Godavari district of Andhra Pradesh. The salient observations recorded during survey are: Economy of the region is mainly dependent on agricultural and its allied activities as their main occupation is rice cultivation in the region including the other crops i.e. tobacco, sugarcane etc. Canals and bore wells are the main source of irrigation in the study area Education facilities are available in the form of primary and middle schools. In some villages, it is extended up to high school. For higher studies people avail the facility from the nearest town. Wood and LPG are mainly used as fuel. Quality of houses is good and mostly people are having well-constructed houses. 45

56 Average family size is between 3 to 6 members in the study area. Sanitation facility is quite satisfactory in the region. Government also constructed the toilets for the poor people As regard to the drinking water facility people expressed satisfactory opinion with respect to quality and quantity Roads in the surveyed villages are in good condition, people are satisfied with the transportation facility. Power supply facility is used by the people for domestic as well as irrigation purpose. 46

57 Chapter-4 Anticipated Environmental Impacts, Evaluation and Mitigation Measures 4.1 Introduction: The objective of the impact identification is to formulate Environmental Management Plan (EMP) to mitigate the probable negative impact that might arise during the project activities to the maximum possible extent. Therefore, in order to come to a strategic EMP it is imperative to identify the possibilities at various project stages, impact type and affected environmental component, extent and severity. EIA is an activity designed to identify and predict the impact on the environment, on human health and ecology, taking into account the requirements of legislative proposals, policies, programs, operational procedures and to communicate information about the impact. The identification of the potential impacts during the exploratory drilling activity on various environmental components namely Air, Water, Soil etc., are discussed below: Tale-4.1: Key Potential Impacts of Exploration Activities Potential impacts Potential Physical Environmental Impacts Potential Biological Environmental Impacts Potential Environment Impacts for onshore activities Sedimentation Erosion Disturbance of sensitive areas Soil compaction and disturbance Groundwater disturbance Drainage alteration, surface seepage, drainage lines and creek disturbance Hydrocarbon contamination Fire Disturbance to fauna including breeding seasons or migration paths Noise and light disturbance Disturbance of rare and endangered flora and fauna and threatened ecological communities 47

58 Potential Social Environmental Impacts Introduction of noxious weeds and vermin, exotic species, flora and animal diseases Encroachment into quarantine areas Disturbance to habitats and vegetation communities Disturbance to heritage sites Disturbance to archaeological sites Disturbance to scientific study sites Disturbance to tourism Public disruption Disturbance to pastoral or farming activities Disturbance to horticultural activities Disturbance to aesthetics (visual impact) Disturbance to ethnographic sites Third party access denial or creation The major element involved in the process of environmental impact assessment is identification as it leads to other elements such as quantification and evaluation of impacts. Although in general, a number of impacts can be identified while describing the project, all the impacts may not be considered significant. Hence, it is necessary to identify the critical impacts that are likely to cause significant impact on various components of environment due to proposed drilling activity. Impact significance criteria is given in the Table-4.2 Table-4.2: Impact Significance Criteria Impact Significance Major Adverse Moderate Adverse Minor Adverse Insignificant Adverse Beneficial Criteria When the impact is of: high intensity high spread (regional) or moderate spread high or moderate duration When the impact is of moderate intensity high or moderate or low spread high or moderate or low duration When the impact is of: moderate or low intensity low spread moderate or low duration When the impact is of low intensity low spread low duration When the impact are positive 48

59 A number of techniques are available for identification of impacts. In the present case Network Method has been adopted for understanding the cause-condition-effect relationship between an activity and environmental parameters. Various activities and their likely impacts due to exploratory drilling have been identified and shown in the Table-4.3. Table-4.3: Activities Impacts/Risks Interaction Impacts/ Risks Activities Environmental Sensitivities Physical Biological Socio-economic Soil & Sediments Water resource & Quality Air Quality Flora Fauna Reserve Forest/ Protected Forests Living condition Local Economy Existing Oil & Gas Business Traffic Hazards Onsite Risks (Occupational Exposure) Culture/ Archeological Places Tourism/ Leisure Drilling Site Preparation Physical Presence including Land acquisition/lease Site Clearance Site Preparation Equipment Transportation Campsite Drilling Operation Atmospheric emissions Noise & Vibrations Waste generation Storage of Flammables Well kick Land Use (Mudflats/ Agriculture) The detailed list of activities and actions described earlier in this report has been taken into consideration for generation of cause-condition-effect network (i.e. chain of events). The idea was to account for the project activity and identify the types of 49

60 impacts, which would initially occur. The next was to select each impact and identify the secondary and tertiary impacts, which induced as a result. This process was repeated until all possible impacts were identified. While identifying the impact networks for drilling operations in the study area all significant activities such as land acquisition, road/site clearance, drill site preparation and diesel generation set operation have been considered The availability of energy resource (oil/gas) the end product has been considered for the purpose of economic benefits. The identified impacts for various components of environment viz. air, noise, water, land and socio-economic are presented in Figs. 4.5 to 4.9 respectively. The comprehensive environmental impact network for proposed exploratory drilling in typical case is presented in Fig Impact assessment and mitigation measures This section discusses the possible impacts of the project activities on the existing environmental receptors, particularly on the environmental sensitivities of the area which get effected by the project. It discusses probable impacts during various phases of the project life cycle to the environmental receptors. Identification of impacts would help in delineating appropriate mitigation measures to reduce the adverse impacts Potential Impacts on Air Quality: A number of sources are there to cause potential impacts on air quality, which are as follows a. Emission from DG sets b. Other emissions a. Emission from DG sets: The power requirements for the operation of the drilling is met by using diesel generator sets. Four generators of each 840 KVA are installed at the site. The cumulative power generating capacity of the four units is 3360 KVA. of power at peak periods. The DG sets are primary contributor to air pollution at the drill site. The pollutants emitted by a DG set consists of Particulate Matter (PM), Sulphur-dioxide (SO2), Nitrogen Oxides (NOx) and Carbon Monoxide (CO). To assess the quantitative impact of generation of these gases, air quality modelling has been 50

61 carried out using approved FLUIDYN-India software. Fluidyn-PANEIA models the atmospheric dispersion of continuous emissions from industrial sites. To stimulate and atmospheric dispersion uses 3D deterministic solutions of fluid mechanics of Euler equations. DG sets used for the purpose of impact predictions on air environment and emission sources can be classified into point and area sources. This model is used to predict the ground level concentrations of PM, NOx, SO2 & CO due to the proposed drilling activity. The Ground Level Concentrations (GLC) were predicted on 24 hourly average basis and the concentrations are shown in the form of isopleths, super imposed at the proposed drilling location at SU-SG-A. The concentration of SO2 in the emitted gas will depend on the fuel source i.e HSD. Since diesel contains very low Sulphur,(125 ppm produced from the own refinery at Tatipaka) will lead to very low SO2 emissions. Table-4.4: Details of DG set & flaring emissions Sl. Parameters Unit Quantity Test Flaring No. 1. Capacity 840 KVA (840X 4 DG Test Flaring # sets)= Number of Stack Nos 4 1(Occasional) 3. Fuel type* HSD (Sulfur-120 ppm) Gas consumption* (Kg/hr) 125 M 3 /hr 4. Density of Diesel gm/cc Stack Height m Stack Diameter m Temperature C Velocity m/s Gas exit flow rate m3/sec PM mg/nm SO 2 mg/nm NO x mg/nm CO mg/nm Predicted Ground Level Con. GLC) Max. GLC at 0.5 km NE direction 14. PM µg/m SO 2 µg/m NOx µg/m CO mg/m #The test flaring will be temporary in nature and will be for about 24 to 48 hours period depending upon the gas encountered in the well. It is expected that about 3000 m3/day of gas will be test flared with an hourly average quantity of 125 m3/hour. Usually production testing after completion of drilling last only for few hours in case of exploratory wells. 51

62 The details of Air modelling for DG sets using HSD fuel from Tatipaka refinery (BS- III fuel) is given in Table: 4.4. The various GLC contours for PM, SO2, NOx and CO are superimposed on the study area map and shown in figures: The maximum predicted concentrations for PM, SO2, NOx and CO due to DG set operation is estimated to be 15.0 ug/m 3, 12.5 ug/m 3, 13.0 ug/m 3 and 0.3 mg/m 3 respectively. 52

63 ( E I A/EMP for Exploratory drilling of shale gas/oil wells in KG Basin, West Godavari District, AP, Fig-4.1: Output Model- Particulate Matter (PM) PM Fig-4.2: Output Model- Sulfur-di-Oxide (SO 2) 53

64 Fig-4.3: Output Model- Nitrogen Oxides (NOx) Fig-4.4: Output Model- Carbon Monoxide (CO) 54

65 The baseline ambient air quality has been added to the maximum incremental concentration to get resultant air quality parameters during different stages of drilling activities Table-4.5 Resultant PM, SO2, NOx, & CO in Ambient Air (μg/m 3 ) S. No Parameters Maximum Incremental Concentration Baseline AAQ Resultant Max. GLC DG sets 1 PM SO NOx CO (mg/m3) AAQ Standard(CPCB) The above air quality data reveals that even after considering incremental concentration in to baseline air quality from various operations, Ground Level Concentration (GLC) does not exceeds limits as prescribed by National Ambient Air Quality Standards (NAAQS) It may be concluded that impact of proposed activities will be insignificant. b. Other Emissions: Other types of atmospheric pollutants principally associated with the project activity is of emission of dust during initial site preparation, transportation of material and equipment and dismantling of rig during closure phases. This dust emissions will settle down at nearby residential areas and agricultural fields. The potential dust to be emitted during site preparation is strongly dependent on the different type of activities taking place such as movement of vehicles along approach and connecting roads, their speed, soil stripping and soil refilling during site restoration. The prevailing wind speed and direction may carry these dust particles towards sensitive receptors and can act as a key factor in determining the frequencies and durations with such impacts might occur Mitigation Measures Measures proposed to mitigate the effects of air emissions are as follows: 55

66 The exhaust of the DG sets will be at sufficient height to allow dispersions of the pollutants and periodical maintenance of DG sets so that emissions will be under limits. Low sulfur diesel (Sulfur: 125 ppm) to reduce emissions of pollutant SO2. Most of the equipment, machinery and vehicles have inbuilt pollution control devices. The storage and handling of top soils and materials will be carefully managed to minimize the windblown material and dust. Minimization of flaring and emissions from any production tests as far as possible and test flaring will be done by elevated flaring (stack) system without cold venting Noise Environment The proposed drilling operations and related activities will lead to considerable emission of noise that may have significant impact on the surrounding communities in terms of increase in noise levels and associated disturbances. The potential impacts on noise level may arise out of the following Noise from the drilling rig: The expected exposure levels of noise at different places of the drilling rig is shown in the Tble-4.6. The estimated background noise levels in the villages near the drilling site varied between 35.1 and 63.5 db(a). It is estimated that the general noise levels near the drill site will vary from 45 to 80 db(a). On the basis of expected noise levels calculated through standard attenuation model, it is observed that the noise levels in the region would be within the standard limits (IS: 4954). The increase will only be marginal in comparison to the existing noise levels. The impact of the noise on general population is therefore expected to be insignificant. 56

67 Table-4.6: Noise Exposure Levels of drilling Rig: Noise levels in Electrical Rig db(a) Occupational Exposure Human Settlement Exposure 71 Leq (12 hrs) on the -- derrick floor 60 Leq (12hrs) within the -- premises of drill site Leq (24 hrs) villages 1 km away Ldn villages 1 km away during night (9 pm to 6 am) It has been observed that generally all the noise sources in a rig are scattered in an area of about 100 m x 100 m. As the proposed drilling operations are carried out at 0.5 to 1.0 km away from the human habitation, the first approximation one can assume that for general population in the village, every drilling site is a point source of noise. When a drilling rig is in operation at its maximum efficiency, the drilling platform (derrick) can be assumed as the location of the hypothetical source of noise at the drill site where maximum noise levels are recorded 71 db(a). Further the noise levels recorded in various directions at a radial distance 50 m can be used for estimation of magnitude of the average noise equivalent source. Noise level due to such a source works out to be 44 dba at a distance of 1 km. As environmental attenuation, particularly due to air absorption and crops/grass/shrubs cannot be neglected the levels will work out to be less by 7 to 10 dba depending on the nature of vegetation, relative humidity and frequency of the noise. Therefore, average noise levels at about 1 km from the drilling rigs would be around dba. The overall background noise levels would increase by 3-4 dba and 2-3 dba during day and night time respectively due to drilling operations. Day night sound level, Ldn is often used to describe community noise exposure which includes 10 dba night time penalty. As per WHO recommendations there is no identified risk in damage of hearing due to noise levels less than 75 dba (Leq 8 hrs). Most of the international damage risk criteria for hearing loss permit Leq (12 hrs) up to 87 dba. Further, WHO recommendations for community noise 57

68 annoyance, permits day time outdoor noise levels of 55 dba Leq, and night time outdoor noise level of 45 dba Leq. The damage risk criteria for hearing, as enforced by OSHA (Occupational Safety & Health Administration) to reduce hearing loss, stipulate that noise level up to 90 dba are acceptable for eight hours exposure per day. At places except the drilling platform, continuous attendance of workers is not required. Hence, the noise levels only at the drilling platform are of concern for occupational consideration. The drilling rig and associated machinery including the high power DG sets is likely to emit noise in the range of db (A) and can be experienced at a distance of 15 m from the drill sites Noise emanated by Machineries and equipment In addition to the drilling activity, site preparation/closure related activities will also involve the operation of heavy equipment like pile drivers, loaders, tippers and bulldozers etc. Such heavy equipment are noted to emit considerable noise emissions which will get dispersed in the nearby communities thus resulting in a decrease in noise quality in the immediately adjacent settlement area. Most equipment and machinery will have noise control devices to reduce the emission levels Noise from vehicular traffic Vehicles used for procuring goods, and manpower to the drill site and the subsequent transportation of rig/equipment and debris during decommissioning will use the site approach road and village roads. This will result in increase in traffic density to the site access road which will cause increase in noise levels in the nearby settlement and other sensitive receptors like schools, hospitals etc. located near the drill site. This may cause considerable noise disturbances to few residents living in the nearby areas as they were not very used to with such noise exposure. However this is a temporary in nature hence the impact may be considered insignificant Noise Control Measures Typical mitigation measures for noise will include the following: 58

69 Sufficient engineering control during installation of equipment and machineries is ensured Acoustic enclosures for the DG sets All noise generating operations except drilling is restricted to daytime to the extent possible Personnel Protective Equipment like ear plugs/muffs will be provided to the workers at the site Undertake preventive maintenance of vehicles and machinery to reduce noise levels Water Environment: Water Requirement & Utilization The daily water consumption at the proposed exploratory drilling will be 25 KLD. Out of this 15 M 3 will be consumed for mud preparation and 10 M 3 for domestic consumption (Personnel & Kitchen). The waste water from the cuttings washings, derrick floor cleaning and from de-silter and de-sander will be collected in the HDPE lined waste pits and recycled and re-used after treatment with mobile ETP. No waste water is discharged to the outside water bodies. It is estimated that approximately 700 m 3 of drilling fluid will be formulated during the course of each exploratory well drilled. Drilling fluid or mud is basically a mixture of water, clay, polymers and weighting material with all individual components being environmental friendly. The mud circulation is a closed loop with the return mud going back to the mud tanks. At the end of drilling operations, the residual (unusable) water based mud is discharged in to the waste pit. Since, lined pits will be used for solar evaporation of the unusable mud, the chances of run off or leaching is very low. Therefore, no significant impacts on surface water quality is envisaged due to the proposed drilling activity Land Environment During the drilling operation, two major sources of solid wastes are envisaged: (i) drill cuttings, separated on a shaker (vibrating screen) which is a part of solids handling system attached to rig and (ii) rejected drilling mud with sand and silt separated in de-sander and de-silter. 59

70 Drill cuttings from the wells are allowed to collect in the sump below the shale shaker and removed periodically whereas filtered mud is flowed to circulating tanks. Around 5 to 10 T/day of drill cutting are expected to be generated depending on type of formation and rate of drilling. Mud portion, which is recovered in shale shaker, passes through de-sander and desilter where sand & silt are removed by centrifugal action. The sand silt generated at this unit is contaminated with mud particle and is allowed to flow to waste pit by washing it down. These solids contain mainly dispersed drill solids along with bentonite, barite. It is anticipated that approximately m 3 of drill cuttings will be generated over a period of days from each well. All the drill cuttings after washing collected in the HDPE lined waste pit. These cuttings are inorganic and non-toxic and non-hazardous. All the solids are non-toxic and non-hazardous. Therefore there is no significant impact on the land environment. Further, the concentration of heavy metals like Cadmium and Mercury will be less than 3 ppm and 1 ppm respectively as stipulated by the MoEFCC Biological Environment Terrestrial Environment Prediction of Impact on Biological Environment due to any exploratory activity is practically difficult because: Living subjects has a natural variation in numbers, changes in numbers cannot always be directly attributed to changes in the environment Most of the impacts on the living system or ecosystem takes long time period to become fully visible externally As such, the forests are getting vanished and the growing industrialization will affect the plant life due to industrial pollution load and influx of population. Therefore, to minimize the adverse effect of drilling activity, it is proposed to take adequate management measures as prescribed in the EMP. The nearby natural vegetation will be disturbed for short duration till the drilling activity continues due to increase in pollution load. However, it will improve due to follow up of Environmental Management Plan (EMP). Mangrove vegetation does not exist in the area hence no changes are anticipated. 60

71 There are no rare and endangered plant and animal species in the study area and hence no changes are anticipated. As regards soil microbiology, no oil bearing waste will be discharged to the ground and adequate emergency control measures in place to take care of any accidental spills Aquatic Environment Waste mud and effluents from drilling activity will be contained in HDPE lined waste pit within the drill site premises and there will be no discharge to any aquatic environment. No disturbance or damage will be expected to the aquatic environment Socio-economic Environment Critically analyzing the existing status of socio-economic profile vis-à-vis its scenario with proposed project, the impacts of the project would be of varying nature. The predicted impacts are as follows: The proposed activities would generate indirect employment in the region; labour force will be required in site preparation and drilling activities, supply of raw material, auxiliary and ancillary works which will improve the economic status of the local unemployed persons. The commissioning of project would lead to improvement in transport facilities as loose or soft surface rural roads and trails will be upgraded to facilitate movement of the drilling rig and supply vehicles In the event of commercial quantities of hydrocarbons are discovered, more long term employment opportunities would be created and the enhance the availability of fuel to various industries in this region Environmental Impact Evaluation Ecology Agricultural and fishing activities form the source of livelihood for residents living in proximity to the identified drilling areas. Paddy & coconut fields cover most of the area. The impacts on ecology of this area will be insignificant because of short term nature of the activity. There will be no disturbance on surrounding ecology except marginal increase in the pollution levels due to air emissions. However, these 61

72 effects will be negligible and short term, hence diluted fast and regained to the normal levels Environmental Pollution All the drill cuttings and wash water contained in the lined pits within drill site premises, there will be negligible adverse impact on aquatic environment. The air quality of area under reference will not be altered. However, control measures are proposed in environment management plan to mitigate any adverse impact. The noise levels are likely to increase (5-10) db(a) slightly near the drill site during operations. But outside drill site at 200m the ambient noise will be normal. Hence there will be no disturbance to the nearby habitants Socio-economics The impact on community health due to the proposed drilling activities is negligible but the social status will improve due to increase in employment opportunities. There will be positive impact on sanitation, transportation, communication and community health in the region. There will be some occupational hazards due to proposed activities but these hazards will reduce through implementation of precautionary measures suggested in EMP Environmental Impact Statement The impact statement focuses on the study area within block boundary of the proposed drilling sites. The five basic environmental components of concern are: Air Environment Noise Environment Water Environment Land Environment Socio-economic Environment For each of the above components of environment, the impacts are identified through cause-condition network predicted through appropriate mathematical models and valuated through environmental evaluation system. 62

73 4.9.1 Air Environment The impacts on air emissions arising out of proposed activity are mainly due to emissions from DG sets, temporary flaring during well testing. There will be only marginal increase in SPM, NOx, SO2 & CO. The impact of these parameters will be negligible from the proposed activity since the terrain is plain and sufficient amount of atmospheric mixing is available in that region Noise Environment The impact of noise generated by the drilling on the general population is expected to be insignificant. Table-4.4 shows the expected noise levels due to drilling. On the basis of expected noise levels calculated through standard attenuation model, it is observed that the noise levels in the region would be within the standard limits (IS: 4954). The increase will only be marginal in comparison to the existing noise levels. The impact of the noise on general public is therefore expected to be insignificant Water Environment No significant impacts on water quality are envisaged due to the drilling activity as there is no discharge of waste water to the outside water bodies. All the waste water is contained in the lined waste pit and used for recycling. Garland drain is provided at the site to contain excess water during rains Land Environment The proposed drilling activity will lead to temporary loss of agricultural land for site preparation. The drill cuttings generated are non-toxic and contained in the lined waste pit. The analysis of drill cuttings shows the very less concentration of heavy metals as shown in the table-4.7 Table-4.7: Analysis of the drill cuttings Sl.No. Parameter Unit Value 1. ph Oil & Grease mg/l 6 3. Cadmium as Cd mg/l Mercury as Hg mg/l BDL (0.001) 5. Hexavalent Chromium(Cr+6) mg/l BDL(0.01) 6. Total Chromium mg/l BDL (0.01) 7. Arsenic as As mg/l Copper as Cu mg/l

74 9. Cobalt as Co mg/l Nickel as Ni mg/l Lead as Pb mg/l Vanadium as V mg/l Iron as Fe mg/l Manganese as Mn mg/l Biological Environment Vegetation in the vicinity of the drilling sites will not get affected by proposed drilling because of marginal change in ambient air quality. Short term disturbances on fauna will be there during actual drilling activity. They will be re-oriented once the drilling activity is completed Socio-economic Environment The proposed exploratory drilling in KG Basin, Andhra Pradesh would create certain impacts which are beneficial as well as adverse effects on the socio economic environment. The Prediction of Qualitative Impacts on Socio-economic Environment is described in Table-4.8. Table-4.8: Prediction of Qualitative Impacts on socio-economic environment Parameter Local Regional Direct Indirect Reversible Irreversible Employment Income Transport Education Medical facilities Communication Sanitation Housing Health Recreation Agriculture Cost of living Business Per Capita Income Pollution : Positive Impact, - : Negative Impact, : Insignificant Positive Impacts 64

75 The Positive impacts identified from proposed project are described below: Increase in employment opportunities during the exploratory drilling may have distinctive impact on the socio-economic development of the region Fulfilment of the energy demand in the industrial sector of the region which will ultimately improve the economy of the region Quality of life will improve by proposed project through development of infrastructure resources such as roads, water supply, electricity etc. Many auxiliary and ancillary industries may develop due to the proposed exploratory project activity Negative Impacts Exploratory drilling of oil & gas wells activities have the potential to affect the native communities temporarily. During rig movement and rig building period there will be short-term socioeconomic impacts in the study area that may include increase in floating population (contractual) and there will be marginal strain on the civic amenities like drinking water, sanitation, road transport and other facilities. Occupational hazards in terms of injuries & accidents may occur during movement of rig & drilling of the wells Vehicle and drilling equipment can create noise pollution. Temporary impact on quality of air and land Mitigation Measures All equipment is operated within specified design parameters during drilling. Impact on air quality will be minimized by reducing the duration of testing through careful planning and using high combustion efficiency, smokeless flare/ burners Acoustic enclosures and mufflers will be provided to DG sets to reduce noise levels. Ear muffs/plugs and other protective devices will be provided to the workforce in noise prone areas. Wherever generator noise occurs in proximity to human settlements, sound deadening barriers will be provided 65

76 The effluents (wastewater) and cuttings generated during drilling operations are collected only in lined waste pits and no waste water is discharged outside. 66

77 An Illustrative case of Typical Exploratory Drilling Activity Drilling Primary Impacts Release of Air Pollutants Change in Air Quality Deposition of Particulates on Soil, Water and Vegetation Impact on Visibility Secondary Impacts Impact on Human Health Impact on Flora & Fauna Impact on Soil Quality Impact on Aesthetics Impact on Agricultural Production Tertiary Impacts Impact on Economic Output Fig-4.5: Impact Network for Air Environment Impact on Socio-Cultural Environment 67

78 An Illustrative case of Typical Exploratory Drilling Activity Drilling Primary Impacts Emission of Sound Change in Ambient Noise Level Secondary Impacts Health Risks Impact on Work Output (Quantity and Quality) Migration of Population Tertiary Impacts Impact on Economic Output Impact on Socio-Cultural Environment Fig-4.6 Impact Network for Noise Environment 68

79 An Illustrative case of Typical Exploratory Drilling Activity Drilling Primary Impacts Change.in Surface Morphology Abstraction of Water Release of Wastewater Impact on Runoff/Seepage Impact on Hydraulics of Water course Impact on Water Quality Environmental Health and Aesthetic Risk Secondary Impacts Impact on Agricultural Production Impact on Aquatic Life Cost of Water Treatment Impact on Amenity Tertiary Impacts Impact on Economic Output Impact on Socio-Cultural Environment Fig-4.7: Impact Network for Water Environment 69

80 An Illustrative case of Typical Exploratory Drilling Activity Drilling Primary Impacts Abstraction of Water Disturbance of Soil Disposal of wastewater and sludge Change in Groundwater Regime : Soil Moisture/ Water Level/Flow Pattern/Salt Water Intrusion Change in Structure of Soil : Texture/ Permeability/Soil Aeration Addition/Removal of Substances or Heat To/From the soil Secondary Impacts Impact on Soil Biota Impact on Flora and Fauna Impact on Landscape Impact on Agricultural Production Impact on Livestock Tertiary Impacts Impact on Economic Output Fig-4.8: Impact Network for Land Environment Impact on Socio- Cultural Environment 70

81 An Illustrative case of Typical Exploratory Drilling Activity Drilling Primary Impacts Deployment of Work Force Consumption of Materials/Chemicals and Energy Product Output Change in Employment Pattern Demand for Infrastructural Facilities Environmental Pollution Change in Resource Base Change in Economy Trade and Commerce Secondary Impacts Change in Income Distribution Change in Land use Pattern Impact on Landscape Impact on Amenity/ Recreation Environmental Health and Aesthetics Tertiary Impacts Change in Economic Base and Cultural Values Fig-4.9: Impact Network for Socio-economic Environment 71

82 Exploratory An Drilling Illustrative in PG_ONN_2001/1 case of Typical Exploratory Block District) Drilling Land Aquisition Road Site Clearance Site Preparation Diesel Generators Waste Pit Well Development Workover Operations Drilling Air pollution Noise Pollution Water Pollution Land Pollution Air Quality Impairment Increase in Temp and Odour Increase in Particulate Matter Increase in Noise Levels Surface Water Pollution Ground Water Pollution Estuarine Water Impairment Aquatic Biota Natural Vegetation Leachate Effects Soil Quality Increase in Salinity Effect on Fisheries and Salt Planning Health Effects Economic Benefits Increased Employment Facilities IMPACT ON AIR & NOISE IMPACT ON WATER IMPACT ON LAND IMPACT ON SOCIO-ECONOMIC ENVIRONMENT Fig. 4.10: Comprehensive Impact Network 72

83 4.11 Post Project monitoring Program Monitoring is one of the most important components of a management system. Continuous monitoring needs to be carried out for regulatory requirements, environmental effects and performance of EMP implementation. Exploratory drilling is for short duration 3-4 months. During drilling and after completion of the drilling, analysis of ambient air quality, waste water quality, surface and ground water quality, noise levels in the drilling site, surface and ground water quality at the nearby villages will be carried out to find out the changes in baseline quality of the parameters Occupational Health Surveillance Program: All the employees working will undergo PME (Periodical Medical Examination) by approved medical doctor / Hospital at fixed interval as per the company policy: Up to 45 yrs - Once in a 5 Yrs 45 to 55 yrs - 3 yrs & > 55 yrs - 2 yrs As per plan 10 % employees are being medically examined every year and records are being kept in track for future reference. There are ONGC Panel hospitals / Laboratories / Doctors with necessary medical facilities for PME like X-Rays, ECG, Sonography, PFT, Audiometry, Eye / ENT Surgeon / Blood / urine test etc. ONGC KG Basin has its own dispensaries and empanelled hospitals for employees and their family members for day to day medical problems. Ambulance is available 24 hrs. All the work centers have First Aid Box, Stretcher and 24 Hrs. emergency vehicles. Free medical camps (medical checkup / eye checkup) are also organized by ONGC in villages around the operational area, and accordingly patients are treated and free medicines are given. If required free operations are also done by ONGC under CSR. 73

84 Chapter 5 Environmental Management Plan 5.1 Introduction : Environment Management Plan (EMP) is an important tool to mitigate and reduce the impacts to acceptable level during drilling of exploratory wells. The integration of mitigation measures in drilling activity is supported by environmental requirements with an Environmental Management Plan (EMP). EMP is site specific plan developed to ensure that the drilling activity is carried out in an environmentally sustainable manner where all the stake holders of the activity understand the potential environmental risks arising from the proposed drilling activity and take appropriate actions to properly reduce the probable impact. It also ensures the drilling activity is to be carried out in accordance with the approved design so as to mitigate adverse environmental impacts. The EMP is prepared keeping in view all possible adverse effects resulting from drilling operation in the localized area. The EMP further detail out the mitigation measures to be taken for the drilling activity. Objectives of EMP: To reduce /limit the degree, extent magnitude or duration of adverse impacts. To treat wastages i.e. effluent / waste water, sewage, hazardous waste by adapting efficient technology. To comply with all the regulatory norms and standards stipulated To reduce occupational hazards by creating good working conditions. Continuous development and search for innovative technologies for cleaner and better environment To confirm proper drilling through approved design, supervision and monitoring. 74

85 The Environmental Impact Assessment (EIA) for the proposed exploratory drilling has identified a number of impacts that are likely to arise during the site preparation, drilling, well testing and de-mobilisation. On evaluation of environmental impacts it is observed that the real benefit of the proposed activity can result only if the risks of pollution are minimized. This can be accomplished through implementation of adequate preventive and control measures. The EMP describes both generic and site specific measures, the implementation of which is aimed at mitigating potential impacts associated with the exploratory drilling activity. The EMP comprises series of components covering direct mitigation and environmental monitoring, an outline waste management plan and restoration plan. The exploratory drilling program has been designed to avoid or minimize impacts on the environment. Where residual impact remain, which may have moderate or significant impacts on the environment, mitigation measures have been prescribed in this EIA which will either reduce the impact to an acceptable level or adequately offset it. Based on the impacts identified a conceptual EMP is recommended below. This Environmental Management Plan (EMP) is a site specific document for the proposed shale gas & oil exploratory drilling in Suryaraopeta and Mahadevapatnam PML blocks of Krishna Godavari Basin., Andhra Pradesh. EMP will ensure that ONGC can implement the project in an environmentally sustainable manner. This EMP is developed based on baseline data to mitigate the likely adverse impact on the environment. EMP ensures that the best available technology (BAT) is used for drilling and environmental protection. Effluent waste generated is collected, handled, and disposed as per the standard practice to minimize potential impacts. Resources like water and chemicals are used in a way to reduce overall burden on the environment. The Environmental Management Plan details the strategies for all the stages of the proposed project. The EMPs cover the likely impact from drilling of exploratory wells in the proposed area. The plan has both generic good practices and activity specific control measures. ONGC will work together with Directorate General of Mines Safety (DGMS), Oil Industry Safety Directorate (OISD), Andhra Pradesh Pollution Control Board (APPCB) etc. to manage any potential major impact on the local environment and people in addition to meeting the necessary compliance, ONGC is also committed to strive beyond and will adopt all the 75

86 necessary measures and will carry out ongoing monitoring to ensure their implementation and effectiveness. To develop EMP, the operations of exploratory drilling may be broadly divided in following categories 1. Drill site preparation 2. Mobilization & De-mobilization of drilling rig 3. Emissions and discharges from actual drilling operations 4. Solid waste management 5. De-commissioning and Restoration of site. Mitigation measures to avoid these impacts are described below; Site Preparation For site preparation purposes, padding and fill materials will have to be brought in and laid over the site area to heighten it to above ground level or parallel to ground level. While carrying on the fill operation, the slope of the padded area and the storm water drainage system will be maintained so that the runoff from the site drains out. A garland drain will be built all around the padded area to collect runoff in to waste water pit. At the commencement of site preparation activities, the topsoil of the land acquired for the project will be carefully stripped to its full depth and stored separately. Top soil will be stored where it will not be compacted by vehicles or contaminated and will be stored in a manner that will minimize its loss or degradation. Top soil will not be mixed with sub soil or any other inert material during the entire drilling activity Rig mobilization & de-mobilization The Drilling Project would include trucking loads of rig and related equipment to and from site during the site preparation and closure activities. Transportation would also involve bringing in soil / stone from quarries, raw material and supplies for drilling and movement of personnel. This will require up-gradation of an approach road. All transportation work undertaken will be conducted in compliance with relevant regulations and best practices generally prevailing in India. 76

87 Measures for mitigating the impacts due to transportation are as follows: The route of access roads, other infrastructure, refueling stations, service stations, etc. to be used for transportation will be selected such that they take into account socio-economic considerations. Access routes to be used by traffic will be properly signposted to prevent vehicles from leaving the designated routes and ensure that the appropriate speed limits are enforced particularly through the residential areas. Measures to prevent damage to public roads is taken, to the extent possible. At least a day of advance notice is given to nearby residents for any proposed road diversions and closures, especially associated with ONGC s activities. Traffic flows will be timed, wherever practicable, to avoid periods of heavy traffic flow along main roads. Movement of project related traffic during night-time will be restricted to the extent possible. Clear signs and signals will be set up wherever necessary. Access to adjacent commercial and residential properties are maintained and speed limits are established and enforced for vehicles being used for project related transportation all over the traffic routes. An efforts will be made to minimize vehicle traffic during hours that children are traveling to and from school. Speed breakers are installed on the roads, to control the speed of vehicles Emissions and discharges from drilling operations Air emissions: The main atmospheric pollutants emanated are from emissions from DG sets, gas flaring during production testing, fugitive emissions from the diesel tanks and handling of dry and dusty powders. The adverse impacts of these will be mitigated by adopting following measures: All equipment will be maintained at optimum operating condition. Effect of emissions from DG sets are mitigated by ensuring adequate stack height and using low Sulphur diesel. 77

88 Dry and dusty powders will be stored in sealed containers. Gas flaring will be restricted to the shortest possible testing phase. Fugitive emissions of VOC s from diesel fuel to be reduced by appropriate Storage and handling Wastewater: Approximately M 3 of waste water from the drilling operations and associated cleaning activities at the drill site and M 3 domestic wastewater will be generated per well. The wastewater is collected in a HDPE lined pit recycled and reused after treatment with mobile ETP installed at the site. No waste water is discharged outside. Domestic waste water including grey water will be discharged into soak pit provided at the site Solid Waste Management Drill cuttings: Water Based Muds (WBM) system will be used for exploratory drilling in these blocks. WBM is non- toxic (LC50 >30,000 ppm). The drill cuttings generated while drilling with WBM will be non-hazardous and disposed as per GSR 546(E) dated 30 th August Approximately M 3 wet drill cuttings generated per well. These drill cuttings are collected in an impervious HDPE lined pit. In addition to the drill cuttings, domestic waste generated at drill site will be segregated into bio-degradable and non-biodegradable components. Bio-degradable waste will be disposed in a pit and non-biodegradable waste will be sent to base for further safe disposal Disposal of spent/lube oil: Approximately 500 kg of spent oil and waste lube oil is expected to be generated during the drilling of one exploratory well. This oil is collected and in the barrels and sent to the base stores for further disposal to authorized recyclers De-commissioning and Restoration of site The contemplated steps for immediate decommissioning of the rig will take place only at the abandoned/unviable drilled exploratory wells is as follows: 78

89 a. Removal of Equipment and Materials If the drilled well is found dry/unviable, the rig equipment and associated materials will be removed from the site keeping the well head in place. All empty drums, wastes, used and unused drilling fluids, fuel and lubricants will be removed from the drilling site. Water supply and effluent discharge hoses and associated equipment will be removed. The access road(s) would be reinstated. b. Restoration of well site After the completion of drilling the rig will be dismantled and all the equipment will be shifted to next location. The site will be restored to pre-existing condition by covering with top soil which was removed during site preparation after excavating the filled material in order to allow the affected area to be returned to its pre-project use and productivity. Drilled cuttings and waste mud collected in the HDPE lined pit is allowed to dry completely and covered with the native top soil. 5.2 Noise Management Drilling activities will have short term impacts on surroundings and ONGC adopts a systematic approach to manage these impacts to the extent possible. ONGC will make sure that the machineries and equipment being used comply with the noise emission standards stipulated by the standards. It shall be ensured that sufficient engineering controls (e.g.mufflers) are installed to reduce noise levels at source for vehicle and machinery. In addition to the measures taken during the design and planning phase, further mitigation of these impacts can be achieved through management practices and some of the key measures that can be taken up during the drilling phase are laid down below: Acoustic enclosures will be provided for DG sets to reduce noise levels. Preventive maintenance of vehicles and machinery to be undertaken as and when required. Provide Personnel Protective Equipment (PPEs) like ear plugs / ear muffs to all workers working in high noise areas. 5.3 Biological Environment 79

90 The proposed drilling sites are located in the agricultural fields having low vegetation cover and there is no demarcated forest patch. The economic important herb, shrub and trees are very much distributed no rare or threatened or endangered flora and fauna are recorded in this area. Hence the impact on the vegetation are negligible. The impacts on terrestrial biological Environment (flora & fauna) can be only from atmospheric emissions. However, it was found that the levels are within the standard limits. In conclusion, it is imperative that ONGC as a premier oil producer of the nation voluntarily accepts the responsibility of ensuring the protection of the environment around its operational areas so as to ensure the sustainable development of the area. Further, ONGC shall adopt best available technology to reduce the impact on environment due to oil exploitation activities. 5.4 Socio-economic environment The social management plan has been designed to take proactive steps and adopt best practices, which are sensitive to the socio-cultural setting of the region. This section outlines appropriate mitigation measures to the potential socio-economic impacts identified. The following mitigation measures will be included; During site construction most of the people employed would be semi-skilled. People from adjoining areas especially land losers would be given preference according to the skill sets possessed. Since the project involves the movement of heavy vehicles and machineries in the area, the issue of public safety of the villagers, especially children, is an important concern. During the drilling phase and for the rest of the project activities proper safety measures will be undertaken by fencing the drill site. Communication with local community will be institutionalized and done on regular basis to provide as opportunity for mutual discussion. Create various awareness campaigns in the community, specially related to basic health, hygiene and sanitation. Health awareness campaigns such as free medical camps in the operational areas will be organized. 80

91 Vocational training programs will be organized for the local people that may develop their capacity and skills and will be helpful for them in getting more employment opportunities. Environmental Awareness programs will be organized to bring forth the environmental management measures being undertaken and the beneficial aspects of the proposed project for improving their quality of life. 5.5 Hydrogen Sulfide (H2S) During exploratory drilling there is the possibility of encountering of Hydrogen sulfide (H2S) which is a colour less, flammable and extremely hazardous gas with rotten egg smell. The gas will be detected by installing H2S gas detectors at the rig floor and flow channels. At low concentrations, it causes irritation of the eyes, nose, throat and respiratory system at high concentration leads to the fatality if unprotected. The effect of this gas entered during drilling will be mitigated by taking appropriate measures such as increasing the alkalinity of the drilling fluid and addition of the H2S scavenger. 5.6 Drilling Program Safety Guidelines All API, Indian Petroleum Act and Indian Mines Act (OMR) shall be strictly adhered to. All the drilling safety guidelines shall be strictly followed. The well site supervisor shall carry out regular safety checks. All crew members would be frequently reminded of working in a safe manner through regular mock drills. If unsafe equipment or procedures are observed, operations would cease immediately and the hazard duly corrected. The well site supervisor would ensure that the driller and above will have a valid Well Control Certification and have sound knowledge of the API specification relevant to Well Control Practices (API RP53 and those prescribed in it) and practice the same in all aspects of the job. 5.7 Plans for post drilling well site operation and/ or abandonment 81

92 The site will be fenced in the event the well is successful. The well site will be reduced to approximately 30 m x 30 m for the production phase and all non-essential areas will be fully reclaimed. In the event the well is unsuccessful the well bore will be cement plugged. Any contaminated soils (e.g. b y accidental spills of fuel, lubricants, hydraulic fluids, saline produced water) be removed from the site to an appropriate landfill for further bioremediation. On abandonment, In the event the well is un-successful the well bore will be cemented plugged, the casing will be cut-off below the ground, all other facilities will be removed and any non native fill material will be removed. During site reclamation subsoil compaction will be relieved by scarifying and, all topsoil will be evenly replaced. Newly constructed access will be fully reclaimed unless specifically requested to do otherwise by the landowner. Any irrigation ditches diverted to accommodate a well site will be realigned to their pre-well site configuration in consultation with the landowner. 5.8 Occupational Health Surveillance Program Occupational health hazards identified during drilling operation are given below: Chemical Hazards Noise Hazards Radiation Hazards Illumination Hazards Vibration Hazards Temperature Extremes Ergonomic Hazards Stress related Hazards ONGC will provide their employees with working conditions that are free of known dangers. The following steps will be taken as part of the occupational health surveillance programme: Regular health checkup of all the employees as per the PME Job rotation of the workers and labour force will be ensured for twice a day (12 hrs) shift. Health Hazard Control is done by adopting following measures: Prioritize the hazards based on their risk potential. 82

93 Identify specific work groups affected by each hazard. Determine the controls required to manage these identified hazards. The cost of each identified control versus benefits of its implementation may be evaluated. The health and hygiene of the personnel working at the Drilling Rig will be monitored through periodic health checks of the persons. All employees undergo a periodic medical examination (PME). The record of the health checkup will be maintained centrally by medical section. The medical officer at base recommends appropriate treatment for the persons found to be having any health problems requiring attention. During the proposed drilling operations, inspections of cleanliness will be carried out. First aid boxes will be provided at different strategic locations on the drilling rig. The medical officer posted at drill site will regularly inspect the first aid boxes and ensures that their contents are in order. Majority of the employees on the drilling rig will be trained in first aid. Regular drills and lectures on first aid will be carried out at the rig. Occupational Health Surveillance program is summarized below: Summary of Proposed Occupational Health Surveillance Program Cause of health hazard Risk Recommendations Noise (Draw works, DG sets, Cranes, Fire, Water pump etc.) Hearing loss Noise survey is conducted to identify high noise areas and PPE recommended for working in these areas. Manual handling of Back problem Avoid manual handling of equipment and material heavy equipment and material as far as possible Handling of chemicals Eye problems, MSDS of all hazardous (Chemical stores, chemical ingestion, chemicals available at site. Chemical dosing areas, Chemical labs) and dermal effect of chemicals 83

94 Periodic Medical Examination Policy Periodic Medical Examination (PME) shall be applicable to all regular employees. PME shall be carried out at regular intervals depending on the nature and extent of the risk involved, after the initial pre-employment health examination is as given below: Type of PME Employees to be covered Periodicity General Employees up to 45 years age Five years Employees in age group of 46 to 55 years. Employees in age group of 56 years and above. Three years Two years Specific Employees having hazard based profiles As per requirement Random On need basis-up to 10 % of employees will be examined. Every year PME is conducted at accredited laboratories. 5.9 General Environment Protection Measures Construction activities will be coordinated in consultation with landowners to reduce interference with agricultural activities. Top soil will be stripped to color change or to plough depth and will be stored on the site. The depth of stripping will be on the basis of site specific soil survey. If required for rig stabilization the well site will be temporarily padded with granular fill. The drill site would be provided with sufficient sanitary facilities. Hazardous materials such as petroleum, spirit, diesel lubrication oil and paint materials required at the site during construction activities would be stored as per safety norms. To ensure that the local inhabitants are not exposed to the hazards of construction the site would be secured with manned entry posts. It would be ensured that all vehicles are properly maintained. The vehicle maintenance area would be so located that the contamination of surface/soil/water by accidental spillage of oil/diesel will not take place and dumping of waste oil will be strictly prohibited. 84

95 All irrigation canals and ditches encountered by the proposed well site access and well site will be maintained in a fully functional state after completion of the drilling. 85

96 Chapter-6 Risk Assessment, Emergency & Disaster Management Plan Risk arises out of hazards and hazard is potential condition awaiting to be converted into an unwanted event i.e. accident. Thus risk assessment is concerned with identification of hazards associated in drilling operations along with the aim of reducing, controlling and eliminating hazards from the operations. Once the hazards are identified, safeguards can be recommended, which can either prevent an event from occurring or reduce the consequences, if at all the event occurs. 6.1 Risk Assessment Methodology. The basic steps adopted for risk assessments are mentioned below:- Classifying the work activities into different sub-activities. Identifying all hazards relating to each work activity / process. Making a subjective estimate of risk associated with each hazard assuming that planned or existing control are in place. Rating the risk. Preparing a plan to deal with the issues found by the assessment. Reviewing adequacy of action plan. Hazards associated with each activity or process are depicted in the Fig-6.1 given below: 86

97 Working at Height Lighting Levels Noise Start Up Utilities Raw Materials Activity / Process Slip and falls Moving Equipmen t Shutdown Storage Harmful substance Fire and explosion Manual Handling Emergency Fig-6.1: Identification of hazards in the process Once hazard associated with drilling activities are identified, the level of impact has been assessed based on subjective criteria. For doing this three key elements are considered based on risk assessment methodology. Consequence Probability of occurrence (likelihood) Legislative compliance The consequences of various risks have been ranked into 4 levels ranging from incidental, minor, major and fatality and are shown in Table- 6.1 below. Subsequently, to assign a level of consequence to each risk, criteria were defined for environmental consequences. Legal issues have been taken into account in the criteria sets and in many instances have been given high weightage to make an impact significant. 87

98 Table-6.1: Consequence Factor Consequence Category Criteria Definition Ranking Fatality 4 Fatality Major 3 1. Permanent loss of body part 2. Permanent disability 3. Loss of property > Rs. 5 lakhs 4. Shut down of plant / facility 5. Blow out / explosion 6. Loss of more than 500 man-hours 7. Fire of more than 15 minutes duration 8. Failure of rig critical equipment like draw works, casing line etc. 9. Serious ill health resulting in loss of more than 500 man-hrs. Minor 2 1. Any accident not falling under any of the categories of major incident. 2. Minor ill health Incidental 1 Near-miss Predictions based on observation of previous similar activities have been used in the risk assessment process. All risks associated with the activities have been assessed and it will be included as and when new hazards are identified To assign probability of occurrence to each activity, four criteria were ranked and defined. The criteria for probability of occurrence are shown in Table-6.2 Table-6.2: Probability of Occurrence (likelihood) Likelihood Ranking Criteria Definition Category Frequent 4 Incident is likely to occur at this facility within the next 3 months Occasional 3 Incident is likely to occur at this facility within the next 6 months. Seldom 2 Incident is likely to occur at this facility within the next 1 year. Unlikely 1 Given current practices and procedures, incident is likely to occur at this facility within the next 5 years. 88

99 Legislative Compliance Requirement for any activity risk ranking is given in table below Under legislation Not under legislation 10 1 The evaluation of risk has been expressed as the product of the consequence, probability of occurrence and legislation of the risk, and is given below as follows: Evaluation of Risk = Consequence X probability of occurrence X legislation The Table below shows risk assessment criteria in the scale of and will be used for delineation of preventive actions, if any, and management plans for mitigation of the risk. Table-6.3: Risk Assessment Criteria Ranking (Consequence X probability of occurrence X legislation) Significance Extreme risk must implement additional control measures High risk may require additional control Moderate risk-existing controls are sufficient Low risk 6.2 Risk Assessment This section discusses the risks of the project activities on the human that get affected by the project. The rankings for consequence, probability of occurrence and legislation on criteria set earlier and the resulting risk has been recorded below for each set of risk and the same has been represented in the matrix and documented in Table Risk Associated with Design & Planning If site is selected on natural drainage it will create water logging and germs, mosquito etc will develop that will further spread malaria, chikun-gonia etc to nearby communities. Selection and procurement of improper machinery and equipment may create noise, emission etc that will disturb the habitants. Mitigation Measures: 89

100 Data will be analysed properly for proper site selection. Machinery and equipment that comply national standard and statutory regulation will be selected for procurement Risk Associated with approach road to drilling site Dust, smoke, emission, noise will be generated during road transportation and may disturb surrounding communities by allergic diseases. There may be possibility of road accident during transportation of material. Free movement of children and animal will disturb due to new vehicular traffic. Mitigation Measures: Adequate measure will be taken to avoid accident Watering will be done to reduce dust Machinery and equipment that will be used will comply statutory regulation. Provide safety equipment for worker and create safety awareness among villagers Risk Associated with Rig Transportation and Building/ Dismantling During these process, there may be road accident, electrocution due to large machinery comes in contact with overhead lines, human, animal etc being struck by crane, trailer, truck etc. Sometimes object may fall from truck / trailer due to overload or improper handling. Loaded vehicle may topple due to wet soil or moving on un-compacted soil. Risks associated with these accidents are mainly physical injury, loss of life, damage of equipment. Mitigation Measures Adopting safe operating practice Create awareness among workers involved in the operation. Use appropriate vehicle for transporting machinery Risk Associated with Drilling & Testing Drilling activities will affect the surrounding noise, air quality and consequently receptors residing in the villages is likely to be significant, if not properly managed. Uncontrolled flow from well bore or leakage from fuel storage may create fire, explosion exposing surrounding communities to serious danger. 90

101 Mitigation Measure Adopting Safe operating practices Proper maintenance of equipment Providing safety equipment Job specific training to employees Table-6.4: Risk Assessment Matrix Exploratory Drilling Sl No Activity Sub-Activity Risk Conse quenc e A Probab ility B Legality C Risk Level with existing controls A*B*C A DESIGN & PLANNING STAGE A.1 Physical Presence of well site and associated infrastructure A.2 Procurement of machinery and equipment A.3 Natural Hazards (Flood/ Earthquake) B Site selection/ Physical Presence/ Land on Lease Procurement of Machinery/ Equipment Natural Hazards (Flood/ Earthquake) Illness from Diseases Illness from disturbance APPROACH ROAD TO EXPLORATORY SITE B.1 Road to Exploratory site & Cross Drainage Works B.2 Land filling including Padding B.3 Transport of Material, Spoil & Machinery C Operation of Machineries Transport of Material/ Spoil/ Machinery Operation of Machineries Transport of Materials Construction of Site Transport of Material/ Spoil / Machinery DRILLING & TESTING ACTIVITY Illness from disturbance Injury/ fatality from road accident Illness from disturbance Injury/ fatality from road accident Illness from disturbance Injury/ fatality from road accident

102 Sl No Activity Sub-Activity Risk Conse quenc e A Probab ility B Legality C Risk Level with existing controls A*B*C C.1 Operation & Maintenance of rig and associated machinery C.2 Testing & Flaring of Natural Gas C.3 Workforce accommodation & sanitation C.4 Discharge of Process Waste Water C.5 Sourcing & Transportation Work force, Material (Equipment, chemical, fuel, water) C.6 Technical Emergencies D Power/ Energy generation & consumption Testing / Flaring of Natural Gas Discharge of domestic waste water Storage/ disposal domestic food waste Discharge of Process Waste Water Sourcing / Transportation Work force/ Material Accidental release of gas / liquid hydrocarbon DECOMMISSIONING / CLOSURE Illness from disturbance Illness from disturbance Illness from Diseases Illness from Diseases Illness from Diseases Injury/ fatality from road accident Injury/ fatality from fire, explosion D.1 Transportation of drilling facilities D.2 Reclamation of land Transportation of drilling facilities Transport of spoil/ debris Injury/ fatality from road accident Injury/ fatality from road accident Disaster Management Plan 92

103 In view of the hazardous nature of products / process handled by the ONGC, Disaster Management Plans (DMPs) has been prepared. These plans are based on various probable scenarios like Well Blow Out, Fire, Explosion, Natural Calamities etc. The consequence arising out of such incidents are accurately predicted with the help of latest technique available by various Risk Analysis Studies. To minimize the extent of damage consequent to any disaster and restoration of normalcy is the main purpose of DMP. There are on site Emergency Plans that deal with handling of the emergency within boundary of the plants mainly with the help of industry s own resources. Also when the damage extends to the neighboring areas, affecting local population beyond boundaries of plant, Off-site Emergency plans is put into action in which quick response and services of many agencies are involved e.g. Government, Fire Services, Civil defense, Medical, Police, Army, Voluntary organizations etc Objective of Disaster Management Plan The following are the main objective of Disaster Management Plan: Safeguarding lives both at installations and in neighborhood. Containing the incident & bringing it under control. Minimizing damage to property & environment. Resuscitation & treatment of causalities. Evacuating people to safe area. Identifying persons and to extend necessary welfare assistance to causalities. Finally when situation is controlled, efforts are to be made to return to normal or near normal conditions Disaster Management Plan: Key Elements Following are the key elements of any DMP: Basis of the plan Accident prevention procedures / measures Accident/ emergency response planning procedures Recovery procedure A broad outline of responsibilities and duties of different team members concerning the emergency management plan are given in Figures-6.2 &

104 INSTALLATION MANAGER/ SHIFT IN-CHARGE CONCERNED LOCATION MANAGER/ AREA MANAGER I/C NEAREST FIRE STATION CENTRAL FIRE STATION NARSAPUR TATIPAKA FIRE STATION CONTROL ROOM, GODAVARI BHAWAN ASSET MANAGER TAKES THE COMMAND OF SITUATION RUSHES TO THE SITE WITH FIRE FIGHTING PERSONNEL, FIRE TENDER ETC. INFORM ASSET MANAGER & CONCERN HEADS HEAD MIS TO ED- AM INFORMS/ APPRISES HIGHER AUTHORITY SUPPORT MANAGER HEAD OF SECURITY & FIRE HEAD ENGINEERING SERVICES HEAD DRILLING SERVICES SURFACE MANAGER HEAD WELL SERVICE SUB SURFACE MANAGER SET UP CAMPS, ARRANGEMENT FOR FOOD & OTHER BASIC ARRANGEMENT AMENTIES FOR TRANSPORT OF MEN AND MATERIAL ARRANGES COMMUNICATION FACILITIES MOBILISES ADDITIONAL RESOURCES, MUTUAL AID WORKSHOP SUPPORT, LAYING OF PIPELINE ETC. ARRANGEMENT OF WATER SUPPLY AT SITE, DIGGING OF PITS ETC. HEAD LOGGING HEAD-HSE OVERSEAS SAFETY ASPECTS AT SITE ARRANGES EDICAL FACILITIES MOBILISES CRISIS MANAGEMENT TEAM MOBILISES ALL RESOURCES FOR HANDLING THE CRISIS DGMS OISD APPCB Figure-6.2: Organogram for On-Site Emergency 94

105 ON SITE ASSET MANAGER DISTRICT EMERGENCY DIRECTOR DISTRICT COLLECTOR CHAIRMAN & MANAGING DIRECTOR PA TO DISTRICT COLLECTOR 2 SP OF DISTRICT REGIONAL TRANSPORT OFFICER 1 DIVISIONAL FIRE OFFICER DISTRICT HEALTH OFFICER MEMBER SECRETARY, APPCB, HYDERABAD DISTRICT REVENUE OFFICER Figure-6.3: Organogram for Off-Site Emergency 95

106 6.3.3 Type of Anticipated Hazards The following are major disasters likely to be happened during the drilling/production activity: Well Blowout Fire / Explosion Gas Leakage (H 2S, Natural Gas etc.) Oil Spills Well Blow Out Blow-out (uncontrolled gushing of oil & gas) is the worst situation, which may arise during drilling, due to some unforeseen reasons. Blow out is often accompanied by fire and explosion, exposing workers to serious danger to their lives, burns and poisoning. Prevention of blow outs rests primarily on control of any kick in the well bore. A kick means entry of formation fluids into well bore in large enough quantity to require shutting in the well under pressure. Once a kick is detected, steps can be taken to control entry of formation fluids into the well bore by over balancing the expected bottom hole pressure with properly conditioned mud and operation of safety valves i.e. BOP, whereby the space between the drill pipes and the casings can be closed and well itself shut off completely. Several instruments are provided on a drilling rig for detection of kicks. a. Instrumentation in Mud System Continuous monitoring of condition of mud in the well provides information useful for well control. The following instruments and equipment are used in the drilling mud system for this purpose: A pit level indicator registering increase or decrease in drilling mud volume. It is connected with an audio-visual alarm near the drillers control panel. A trip with float-marking device to accurately measure the volume of mud going in to the well. This is useful to keep the well feed with required quantity of mud at all times. A gas detector or explosion meter installed at the primary shale shaker together with an audio-visual alarm at the drillers control panel to indicate the well presence of 96

107 gas-cut mud in the well. The kick in the well is prevented by keeping the hydrostatic head of the drilling fluid greater than the formation pressure. The primary control can be lost in the following situations: While tripping, if the well is not kept full with the required volume of mud. If there is reduction in hydrostatic pressure in the well due to swabbing, which may be caused if the drilling string is pulled out too fast or by a balled-up or clogged bit, which is indicated by insufficient filling of mud. If there is loss of circulation, which may be caused either due to running in too fast, thereby, causing the weak horizons of the well to break or while drilling through a formation with cracks or cavity. b. BOP Stack In a well, after the surface casing, blow-out prevention (BOP) equipment is installed and maintained before resuming drilling. Annular preventer for closing the well regardless of size / shape of the drill string in the hole or no string in the hole. The spool is Double ram preventer, blind ram for closing against open hole as well as pipe ram for closing against drill pipes. Drilling spool located below the double ram preventer provided with choke and kill lines which are connected to the choke and kill manifold. A non-return valve is provided in the kill line. 97

108 Table-6.5: Standard Operating Practices for Blowout Sl. No. Action Details of action Action to be taken by If the I/C of the operation of the Rig feels the well DIC of the Rig is out of control and could not be brought under control through normal procedure, emergency should be declared. 1. Declaration of well `Out of Control' 2. Switch-off the Power 3. Ensure personal safety Immediately after the Blowout is declared, switch off the Main power system, which can cause the ignition. Call all personnel from the Rig floor area. Ensure whether all the persons reported or not. If anybody is entrapped try to rescue. 4. First Aid If anybody is injured, carry out the first aid and send him to the nearest hospital. 5. Communicatio Report the Emergency to Base control room. n to control room. 6. Communicatio Base control room has to communicate the n to senior Emergency to all the key personnel. officers 7. Activation of SOP 8. Make water supply arrangements. Based on the information received and also after visiting the site, seeing the gravity of situation, SOP for dealing the emergency has to be activated. Make arrangement to connect water line/ spray water on the Wellhead, if the well not on fire. 9. Relief Camps People are to be evacuated from the premises of 1000 meters. If there is release of Toxic gas like H2S, relief camps are to be organized with all facility for the evacuated people till the well is controlled. 10. Crude Oil Make trenches to collect the crude and Containment subsequently transport to nearest GGS 11. Remove the Rig equipment 12. Establish communicatio Remove all the rig unwanted equipment around the wellhead to protect them from the danger of fire and also to create access to the wellhead. In-built communication room has to be mobilized and made operational. DIC of the Rig DIC of the Rig DIC of the Rig DIC of the Rig Base room control Asset Manager I/C services Head HR Fire Asset CMT Head Head RCMT of the Area Head RCMT of the Area 98

109 n center at site 13. Manning of communicatio n center 14. Establish Base control room 15. Establish First Aid Centre 16. Care of Casualties 17. Cordoning of area. 18. Mobilise the Blowout Control equipment from RCMT location. 19. Logistic support 20. Accommodatio n/ Food/ Beverages 21. Action plan for controlling blowout 22. Insurance related matters 23. Construct leveled Surface 24. Pumping arrangements and fill water. Personnel should be deployed on round the clock basis to the communication centre at the problem site. Establish communication control room in the base with the all type of communication facilities. Control room should work on round the clock basis. First aid centre & medical support has to be established. Nearest hospital / Care Centre should be alerted for receiving the emergency cases. Boundary has to be fixed all around the problem area and has to be declared as restricted area. Blow-out control equipment as directed by RCMT should be mobilised. Transport equipment for the mobilization of personnel, equipment, removal of debris etc., are to be provided as desired by Head-RCMT Accommodation for all CMT Experts at nearest possible location. Based on the condition of the well on the surface and Sub-surface & the available data, workout step-by-step detailed action plan with bar charts. Reporting of incident to the underwriters, also supplementation of required data to them, communication of other decision / advise etc., to Head CMT-Ops, claims, pursue of claims. A leveled surface with required hardening has to be provided at a place required by Head RCMT to place the office/ rest/ store room etc. Dig pits as suggested by Head RCMT. Lay the pipeline, and arrange pumps to pump the water from the main source to water pits. Head Info com Concerned services Head Head Medical Services Head Medical Services Head Security LM (Logistics) LM (Logistics) Head HR Head CMT Operations Rep. Finance LM (Works) LM (Works) of 99

110 25. Install Fire Pumps 26. Pin point the equipment /expertise /special services which is not available with RCMT 27. Directional drilling 28. Snubbing services 29. Safety during operations 30. Monitoring of the plan Install fire pumps, Monitors at required places and test them on load. As per the action plan, identify the equipment, workout expertise and services required for each operation also Find out Directional drilling services as desired by Head CMT. Operations could be provided by local team or not. Find out if snubbing unit can carry out snubbing services required or not. Safety of the personnel, equipment etc is to be taken care without compromise during control operations. Action plan has to be monitored on day-to-day basis; constraints if any. 31. Press Briefing Every day or once in three days press briefing are to be organized in consultation with Head CMT operations, Asset Manager. 32. VIP Visits VIP Visits should be planned in such a way that control operation should not be hampered and also safety of the VIPs should be taken seriously. 33. Review meeting Review meeting with regard to progress, constraints if at all should be organized every two days. All the responsible persons noted above should attend the meeting. Head-RCMT Head CMT Operations Head Drilling Services Head CMT Operations Head CMT Operations Corporate communication Asset Manager /CC Asset Manager Asset Manager Fire and Explosion Fire is one of the major hazards, which can result from storage tanks. Fire prevention and code enforcement is one of the major areas of responsibility for the fire service. Hence the facility should be equipped with: Water supply Fire hydrant and monitor nozzle installation 100

111 Foam system Water fog and sprinkler system of Mobile Firefighting equipment or First aid appliances Proper dyke area shall be provided for the storage of chemicals. In the event of a fire, the fire in the dyke area should be addressed first so as to minimize the heat input to the tank A wind direction pointer shall also be installed at storage site, so that in an emergency the wind direction can be directly seen and downwind population cautioned. Shut off and isolation valves shall be easily approachable in emergencies Storage areas must be adequately separate from buildings process areas and other dangerous substances These measures shall be backed up by relief systems such that the combination of vessel design, protection, quality control and relief eliminates the possibility of complete vessel failure Action Plan for Fire Fighting General: As soon as fire is noticed, shout FIRE FIRE FIRE or AAG AAG AAG. Try to eliminate the fire by using proper portable fire extinguishers. Driller-I/C: He shall ensure regularly the working status of fire equipments / its maintenance through fire section and see that they are kept in their respective places as per the need. As soon as, the fire accident is reported, rush to site and take charge of the situation. Inform Mines Manger besides Area Manager as well Fire Manager. Shift In-charge: If situation demands sound Hooter ; call on the nearest Fire Services and Hospital attending doctor. Give instructions to the assembled staff and get the best out of them. Drilling Officials: 101

112 Remove other inflammable materials to the safer distance. Remove important documents to a safer place. The first aid trained persons should be ready to give first aid to the injured persons and move them to the hospital if required. Get well acquainted with the location of the wells. Electrical Officials: No naked flame should be allowed. Generator should be stopped. Electrical lines are required to be de-energized. See that uninterrupted supply of water from tube well to the fire services. Mechanical Officials: Get the instruction from the Shift In-charge to act accordingly to stop the equipments and ready to carry out repair jobs if required like pump problems of fire services etc. Help production officials in removing inflammable materials. Transport Officials: Get vehicles parked at a safer distance. See that approach road is clear for fire services vehicle to the approach the accident site. Security at Gate: To prevent unauthorized entry of persons / vehicles inside the area of responsibility and also to ensure no abnormal activity by unauthorized persons is allowed. Fire Officials: On arrival they fight fire with the assistance of site staff in extinguishing the fire. If the situation still proves to be beyond control, then the help from the nearest agencies could be taken. Fire Control Room A fire control room will be set up for smooth functioning of firefighting/ rescue operations at the site of incident. Manager (F.S)/ one fire officer or senior most person of fire section will be I/C of that control room. Meanwhile one Fire officer will take charge of Control Room of Central Fire Station to assist/ back support for required fire equipment / man power. In-charge control room of Central fire Station will be responsible for arranging of man power and equipment if required at site. RIC/Area Manager: (In Case of Major Fire) 102

113 Pre-identified source of additional water to be used for uninterrupted supply of water. If situation demands, pits be dug to store sufficient water, pipeline be laid to carry water from the sources to water pits. Maintenance party to remain to attend any problem. Besides special maintenance team be immediately sought from the workshop. Arrangements to provide flameproof lights at a safer distance. Arrangements to provide mud and chemicals necessary to control situation. Arrangements for food, water, temporary rest rooms or tents for the officials on the round the clock duty at site. To keep ready fleet of jeeps, tractors, crane to meet demand. Hydrogen Sulfide (H2S) and Natural Gas Leakage Hydrogen sulfide is a colour less, flammable, extremely hazardous gas with rotten egg smell. Effect of Hydrogen Sulfide gas to Health: Low concentrations irritate the eyes, nose, throat and respiratory system e.g. burning / tearing of eyes, cough, shortness of breath. Repeated or prolonged exposures may cause eye inflammation, headache, fatigue, irritability, insomnia, digestive disturbances and weight loss. Measures in case of detection of H2S at the drilling rig: Check the wind direction and evacuate all personnel to safe breathing area. Put on 30 Min. breathing apparatus set Come back to that site in two (use buddy system), with portable H2S detector and monitor the H2S level in the atmosphere. Stop the source of leakage (i.e. close the well) Remove victim, if any to fresh air, if breathing, maintain victim at rest & administer oxygen, if available, if person is not breathing, start artificial respiration immediately or start mechanical/ automatic resuscitator. Call ambulance and sent victim to hospital or doctor. Avoid & extinguish all naked flames Pull out all possible equipment to safe distances. 103

114 Call for fire tender and start spraying water on the sources of leakage to dissolve H2S in water. Evacuate personnel in 500 mts area from down wind direction. Warn nearby inhabitants, if required. Keep in touch with control room for all instruction. Cordon off the area & do not allow entry of any un-authorised person. Effect of Natural gas on Human Health : Colour less, odour less, flammable gas, mainly methane. May cause flash fire. Electrostatic charge may be generated by flow, agitation etc: No occupational exposure limits established. Provide local exhaust ventilation system. Ventilation equipment should be explosion-resistant if explosive concentrations of material are present: 6.4 Contingency Plan for Oil Spill Oil spills occur despite prevention efforts during blow out of the well. They vary in size, from just a few hundred liters to the thousands of liters. Oil spill contingency plan is prepared and in place for the actions to be taken for the cleanup, recovery, storage and transport of spilled oils and bio remediate the contaminated soils. 6.5 Maximum Credible Accident and Consequence Analysis (MCAC) Maximum Credible Accident and Consequence Analysis (MCAC) defines the accident with maximum damage distance, which is believed to be probable. MCA analysis for a proposed exploratory drilling activity does not include quantification of the probability of occurrence of an accident. In practice the selection of accident scenarios for MCA analysis corresponding to a proposed exploratory drilling activity is carried out on the basis of past accident analysis at similar activities, engineering judgment and expertise in the field of risk analysis especially in accident analysis. Methodology: The MCA analysis involves ordering and ranking of various sections/units at proposed activity in terms of potential vulnerability as given below: Study the process details of proposed activity including storage and handling of hazardous materials along with the envisaged inventories 104

115 Identification of potential hazardous sections and representative failure cases Visualization of release scenarios with recourse to consequence analysis Damage distance computations for the credible accident cases. Proposed Project Hazard Event Classification Major types of accidents seen in drilling operations are as given below: Dropped Objects These accidents have at times lead to demolition of parts of the rig structure. Dropped objects may kill personnel, damage equipment or structure, fires, etc. The major reasons for dropped objects hazards are the human failures such as: Not following the rig specific operational procedures Overloading of cranes Incorrect use of slings Lack of personal safety precautions such as waiting under swinging loads Improper housekeeping HSD Release and Fires HSD is used as fuel on the rigs for operating rig engines, mud pump engines and generator sets. Transfer of HSD occurs through tankers to the rig diesel tank by explosion proof pump. Rupture of pipeline or failure of storage tank results in spillage of HSD and a liquid pool being formed. Ignition of the hydrocarbon released leads to primary and secondary effects. Primary effects may include thermal damage to rig structures, burn injuries to personnel etc. and secondary effects may include loss of structural stability of rig, failure of other storage tanks / cylinders etc. which may further aggravate the accidental event Collisions During the transportation of heavy machinery from one well to another well on the rig site there will be a chance of collision of movable materials with the stationary materials. The usage of heavy load cranes without proper operational skills and slipping of materials from the crane grip also results in collision of different materials and a possibility of injuries to the working people near the rig site. The unorganized vehicular movements within the rig site also have a potential for collisions on paved / unpaved roads. 105

116 6.5.4 Blow Outs A Blow-out is an uncontrolled flow of formation fluids caused due to non-detection of well kick. A kick can be defined as a well control problem in which the pressure found within the drilled rock is greater than the mud hydrostatic pressure acting on the bore hole or rock face. When this occurs, the greater formation pressure has a tendency to force formation fluids into the well bore. This fluid flow is called a kick. If this flow is successfully controlled (by shutting BOP stack & pumping mud of higher density / weight), the kick is killed. A blow out is the results of an uncontrolled kick. A blow out can release large volumes of potentially dangerous formation including gas & water. Blowouts can cause reservoir depletion & / or productivity impairment to a point where the zones are no longer commercial. The drilling rig equipment can be completely destroyed during a blowout. A blow out is generally accompanied by fire & explosion. The workers are exposed to serious danger to their lives, burns & poisoning due to suffocation due to smoke generated from hydrocarbon fires) and the heat destroys the derrick & installations. If the gas gushing out from the well does not catch fire, there is also a risk of explosion Modes of Failure Atmospheric Storages of Liquids HSD Storage on the rigs is in main storage tanks generally located at safe distance from the well. The main storage tanks transfer the HSD to the consumption points (engine room and near cranes, material handling equipment etc.) through HSD lines. Conditions such as overfilling, bottom nozzle failure, natural calamities, damage of tanks due to falling object etc. may result in failure of the storage tanks and spillage of their contents to the surroundings. This will result in a pool of liquid being formed, which will start evaporating and may catch fire if ignited. The quantity of diesel stored at a time at site is 40 m 3 in two storage tanks of 6m length and 2.5m diameter. One pipeline is connected to transfer diesel to the rigs and D.G.sets. Pipeline failure on the rig may occur due to accidental impact (as due to a dropped object) at flanges, welded joints and / or due to corrosion etc. The pipeline failure results in a pool of 106

117 HSD being formed which may ignite on getting a source of ignition. Hose pipe conveying HSD may leak due to wear and tear and / or at the connecting junction and / or a cut due to accident. Table-6.6: Event Classification Type of event Blow out Crane accident Explosion Falling load Fire ire Machinery failure Spill release Structural damage Well problem Other Explanation An uncontrollable flow of gas, oil or other fluids from the reservoir, i.e. loss of (1) barrier (hydrostatic head) or leak and loss of (2) barrier i.e.bop. Any event caused by or involving cranes or any other lifting equipment Explosion of HSD tank Falling load / dropped objects from crane, derrick, or any other lifting equipment. Fire Falling of mast Loss of containment. Release of fluid or gas to the surrounding from unit s own equipment/ tanks causing (potential) pollution and /or risk of explosion and /or fire. Breakage or fatigue failures (mostly failures caused by weather but not necessarily) of structural support and direct structural failures. Accident problem with the well Event other than specified above. Other events leading to accidents in exploratory drilling operations and brief descriptions of these is presented in Table-6.6. The Table-6.7 tabulates the damage effect on equipment and people due to thermal radiation intensity. 107

118 Table-6.7: Effect of Thermal Radiation S.No. Incident Radiation (kw/m 2 ) Damage to Equipment Damage to process equipment Type of Damage Intensity Minimum energy required to ignite wood at indefinitely long exposure without flame Maximum thermal radiation allowed on thermally unprotected equipment Minimum energy to ignite with a Damage to people 100% lethality in 1 min. 1% lethality in 10 sec. 50% lethality in 1 min. Significant injury in 10 sec % lethality in 1 min flame Causes pain if duration is longer than 20 Sec, however blistering is unlikely (Ist degree burns) Causes no discomfort on long exposure 6.6 Identification of accident scenarios for consequence analysis Accident such as falling objects and those involving cranes and lifting equipment can have high frequency of occurrence, but the consequences are limited (to the primary hazard)-such as direct damage to part of rig structure, injury to personnel. However, accidents such as spill / leak of liquid/gaseous hydrocarbons fuels leading to fire and/or blow out leading to fire/explosion have low frequency or occurrence but can lead to high hazards especially due to the limited space available on the rigs. Rupture of diesel storage tank due mechanical structure failure. Release of methane gas from blowout Failure of Acetylene Gas Cylinder Consequence Analysis: The major hazard scenarios for the proposed exploratory drilling activity are determined by adopting MCA analysis Pool fire due to rupture of diesel storage tank 108

119 An amount of 40 KL diesel is stored at rig site for supplying to rig system. The dimension of the storage tank is 6 m length and 2.5 m diameter. The diesel is stored at atmospheric pressure. Detailed computations for the pool fire have been carried out and the results for heat radiation effects and various damage distances are given below. Red: 20 meters kw/(sq.m)= potentially lethal within 60 sec Orange: 30 meters (5kW/(sq.m) = 2 nd degree burns within 60 sec) Yellow :48 meters---(2.0 kw/(sq.m) = pain within 60 sec The damage distance for first degree burn heat radiation effects is 20 m from edge of the pool. The maximum thermal load (kw/m2) at different distances for diesel fuel are shown in Fig: 6.4 Fig-6.4: Threat Zone for Diesel Tank Rupture Methane gas release from Blowout Blow out is an incident where formations fluid flows out the well or between formation layers after all the predefined technical well barriers or the activation of the same have failed. Oil well: A well where the formation has an estimated gas/oil ratio (GOR) less than 1000 Gas well: A well where the formation has an estimated gas/oil ratio (GOR) exceeding 1000 For onshore blowouts the Albeta Energy and Utilities Board (EUB) maintains a database of onshore drilling incidents. The database contains incident reports for individual well control 109

120 occurrences. The frequency of occurrence for blowout is 1.1x10-3. This blowout and well release frequency for onshore operations can be intend to be applied for world-wide drilling activities. Assuming gas well blow out scenario, the MCA analysis has been carried out for methane gas release from proposed exploratory drilling activity. Methane gas is released from the blowout kick of well the rig operations. Since this is exploratory drilling activity, it is difficult to predict the amount of gas release from the blowout incident. Hence four cases of methane gas capacities are considered for MCA analysis. The type of accidental release is a BLEEVE (Boiling Liquid Expanding Vapour Explosion) to atmosphere. The heat radiation effects are summarized in the table-6.8. Table-6.8: Heat Radiation Effects due to Blowout of well Scenario/Blowout Maximum damage distance (meters) of well kw/m2 kw/m2 kw/m2 kw/m2 kw/m2 kw/m2 Case-I Case-II Case-III Failure of Acetylene Gas Cylinder: The acetylene cylinders are used at the rig site for various welding purposes. There are chances of failure of acetylene cylinders while in operation due to over pressure/high thermal effects. In case of cylinder failure a jet fire scenario is expected. The safe distance is found to be 133 m from the pool. The heavy distance is found to be upto 59 m due to explosion scenario. The heat radiation/pressure wave effects due to the rupture of cylinders are shown below. Threat Modeled: Thermal radiation from jet fire: Red: 59 meters--- (10.0 kw/sq.m) = Potentially lethal within 60 sec) Orange: 85 meters---(5.0 kw/sq.m) = 2 nd degree burns within 60 sec) Yellow: 133 meters---(2.0 kw/sq.m.)= pain within 60 sec) The maximum thermal load (kw/m2) at different damage distance for Failure of acetylene gas cylinder are shown in fig

121 Fig-6.5: Threat Zone for Failure of Acetylene Gas Cylinder The quantitative estimates of the heat radiation of the flammable substances present at the drilling rig reveals the impact of any accident due to the above MCA scenarios to the drilling operations. -xxx-- 111