Environmental Impact Assessment of Hindustan Oil Exploration Company s Drilling Project-Dirok and N.Ledo

Transcription

1 Environmental Impact Assessment of Hindustan Oil Exploration Company s Drilling Project-Dirok and N.Ledo EIA Executive Summary Prepared for Hindustan Oil Exploration Company Ltd Prepared by SENES Consultants India Pvt. Ltd K December, 2006 i

2 EXECUTIVE SUMMARY INTRODUCTION: Oil and gas constitute the important segment of energy consumption in the country. Nearly 30% of India s energy needs are met by oil, and more than 60% of that oil is imported. Keeping the required growth rate of GDP and rising energy demand for hydrocarbons in view, the Government of India has come out with plans to encourage national, private and foreign companies to explore and develop the hydrocarbon prospects. Hindustan Oil Exploration Company (along with its Joint Venture Partners) has been awarded blocks in various parts of India under Production Sharing Contract with the Govt. of India. AAP-ON-94/1 Block has been awarded to the Joint Venture Consortia comprising of Hindustan Oil Exploration Company (HOEC) with participating interest of %), Indian Oil Coporation (43.54%) & Oil India Ltd (16.12%) for exploring the hydrocarbon prospects within the block boundaries, under a Production Sharing Contract (PSC) by the Governm ent of India. Presently HOEC is the operator of the block. Previously, Premier Oil North East India BV was designated as the operators vide Government of India (GoI) Letter No. O-19024/5/1/2001-ONGDV dated 14 January However, with effect from January 2006, HOEC has enhanced its participating interest from the existing 25% to % and assumed Operator-ship following the withdrawal of Premier Oil. Indian Oil Corporation (IOCL) and Oil India Limited continue as the consortium partners in the block. During the first half of 2006, HOEC as Operator has acquired and processed 68 lkm of 2D seismic data and HOEC is now planning to drill the exploration wells to determine the presence of hydrocarbons in the identified geological formations. The proposed drilling campaign at Dirok and N.Ledo area aims at prospecting of oil and gas in the Block (AAP-ON-94/1) of Assam by drilling two exploratory wells. The drill site at Dirok is located within the premises of Dirok Tea Garden of Williamson Magor Group while the drill site at N.Ledo is located in the vicinity settlement of Lalpahar near Lekhapani. Both the drill sites lie within the Tinsukia district of Assam.Compliance with various national and state level environmental regulations, standards as well as international laws and best practices are required for the project. SENES India has carried out an Environmental Impact Assessment (EIA) for this project using a scientific methodology of assessing environmental and social impacts for the project and then arrived at a site specific Environment Management Plan (EMP). K December

3 MAJOR ACTIVITIES INVOLVED IN THE PROJECT The wells will be drilled to determine the presence of hydrocarbons in geological formations some 2500 metres below the mean sea level. The objectives of the exploration wells are as given bleow :? To drill and evaluate the hydrocarbons prospects safely? To drill and evaluate the prospects without impact to the environment? To determine the hydrocarbon potential of the designated prospects Drilling is planned to commence during May 2007 with an estimated drilling period of 30 days, testing period of 15 days and a possible additional contingency period of 15 days per well. The exploration wells will be drilled using a Land Rig. HOEC will hire the services of a recognised drilling contractor to drill these wells. Drilling: Wells are drilled in sections, with the diameter of each section decreasing with increasing depth. Before commencing the actual drilling large diameter pipe (Conductor) is lowered into a hole and cemented/ grouted. Conductor pipes provide a conduit for the return fluid during drilling next section and also prevent unconsolidated material falling into hole and potential washout problems. Drilling Fluids; During drilling operations a fluid known as drilling fluid (or mud ) is pumped through the drill string down to the drilling bit and returns between the drill pipe casing annulus up to surface back into the circulation system after separation of drill cuttings /solids through solids control equipment. An environment-friendly water-based mud system will be used for drilling the wells. Unlike an oil-based mud system, the use of water-based mud will not pose any risk of contamination to subsurface formations, and the disposal of the fluid and the cuttings will also be less problematic. Well Testing: Normally, in the event that hydrocarbons are encountered in sufficient quantities, as determined by wire-line logging, a temporary drill stem test string may be run and the well fluids flowed to surface and processed using a surface well testing package, involving the oil being stored and trucked off site and associated gas being flared to atmosphere. This flaring will be a short term activity. Completion of Drilling: On completion of activities, the well will be either plugged and suspended (if the well evaluations indicate commercial quantities of hydrocarbons) or will be killed and permanently abandoned. If the well is abandoned, it will be sealed with a series of cement plugs, all the wellhead equipment will be removed, leaving the surface clear of any debris and the site will be restored to its original or near original state. Restoration and Rehabilitation: If no indications of a commercial quantity of gas are encountered either before or after tes ting, K December

4 the well will be declared dry, accordingly plugged and abandoned, and the site restored in line with local regulations and good industry practice. The drilling operations, which are temporary in nature, will generate noise, air emissions and drilling waste. It will also involve transportation of drilling rig and machineries, raw materials, fuel, and manpower and therefore lead to increase of traffic density in the selected routes. The wastes from the drilling operations will be tested and disposed on-site in a lined pit built and operated by HOEC and the treated waste water will be discharged into natural drains, complying with stipulated standards and in conformity to industry best practices. BASELINE ENVIRONMENTAL STUDIES An understanding of physical, biological, socioeconomic environment was gathered through various studies and stakeholder consultations in the area. The studies reveal that the noise and air quality in the project vicinity and water quality in the Burhi-Dehing River are similar to a typical undisturbed rural setting. The general and average soil character of cultivable land in this district is mainly alluvial and composed of mixture of sand (coarse to fine) and clay in varying proportions. The general geochemical characteristic of the soil is moderate to slightly acidic. The new alluvial soils formed due to inundation of land by river at intervals contain more percentages of fine sand fine silt and are less acidic. Such soils are often neutral and even alkaline. Large expanse of low - lying land characterized by heavy clayish soil with a high percentage of nitrogen is good for rice cultivation. The study area falls in the catchment of the Burhi-Dehing River which is also the main river of the district. In Tinsukia, Burhi-Dehing is the major river originating in the Naga-Patkai Range, flowing in westerly direction. It serves as main drainage to the district and is joined by some major rivers such as Tirap & the Dirok River on it s westwardly course to Brahmaputra River. The project site (Dirok) falls within the overall watershed of the Burhi-Dehing River, with the drainage in the site surroundings being controlled by numerous small nallas, including Ongchap Jang Nalla. The general slope of the Dirok site is towards north-north east. The drill site at N.Ledo falls within the watershed of the Tirap River, with the drainage being controlled by a seasonal nalla flowing along the NW boundary of the site to meet with the Ghuma Mandir Nalla. The general slope of the N.Ledo site is towards the north-north west. The turbidity in all the surface water bodies during the monsson season was monitored to be quite high due to the surface runoff from the surrounding areas. The Dissolved Oxygen level in the water courses indicates a moderate to good water quality of all the water courses. The ground water quality of the area meets the permissible limits of the potable drinking water standard IS Though the region falls under the Indo-Burma Ecological Hotspot, the area in the vicinity of the project does not include any sensitive ecological habitats except the presence of Dehing-Patkai Wild Life Sanctuary located about 1 kms from the Dirok site. The Sanctuary is considered to be K December

5 important from the viewpoint of biodiversity and nature conservation and has been given due importance in the present study. The socioeconomic profile of the area matched with general data of the district and the common problems identified were lack of drinking water, power supplies and sanitation facilities and the non-existence of good access roads to the villages. ENVIRONMENTAL IMPACTS ASSESSMENT The potential impacts of the project on different components of the environment was systematically identified and evaluated for significance. The principal concerns that emerged are: 1 Temporary loss of top soil and land fertility; 2 Noise disturbance and air quality impacts to sensitive receptors located close-by; 3 Increased vulnerability of local inhabitants to road accidents. 4 Some of the anticipated benefits from the proposed project are as follows:? Potential improvement of some basic facilities for the local communities;? Job and business opportunities for the local people. ENVIRONMENT MANAGEMENT PLAN Site-specific Environment Management Plans (EMPs) to prevent and mitigate signif icant adverse impacts and accentuate beneficial impacts are proposed. The key mitigation measures will include: 1. Use of appropriate engineering controls and rehabilitation of sensitive receptors to minimize impacts of air emissions and noise disturbances to the receptors; 2. Reinstatement of the site area before being handed over to the land owners; 3. Manage drill cuttings, wastewater, hazardous and other wastes in accordance with regulatory standards and guidance documents, thereby reducing risk of pollution / contamination in receiving water-bodies and other environmental media; 4. Optimal utilization of natural resources, raw materials; 5. Employment, training of local people considering the local skill availability; 6. Measures and controls to manage transportation impacts on local people and environment. The EMP has been designed with flexibility, so that it can be monitored and adapted to future changes in project design, scope, or the environment. ENVIRONMENTAL MEASURES TO BE ADOPTED BY HOEC Every industrial activity interacts with the environment and leaves some environmental impacts. Some environmental impacts associated with the current project are also available. As per good industry practices, such environmental impacts arising out of the project are identifie d well in K December

6 advance and the consequences are assessed for incorporating the preventive / mitigative measures through a precautionary approach. HOEC s approach to environmental protection broadly includes:? Understanding the baseline environmental status of the area where the new project is proposed;? Assessing the environmental impacts associated with the project through reputed environmental agencies;? Incorporating the state-of-art technologies and best industry practices in the project for minimising adverse environmental impacts, if any, in various stages of the project;? Adhering to the regulatory standards and guidelines and regular monitoring in the implementation HOEC s COMMITMENT HOEC is committed to the prevention of pollution and protection of environment through a precautionary approach. In line with this objective, HOEC will embark on adherence to best industry practices in its operations and committed to use the state of art technologies for waste minimization. Careful consideration will be given to minimizing the amount of waste generated and controlling its eventual disposal. All waste material will be segregated by type; garbage will be stored in a designated area and disposed as per norms. Where possible, wastes will be recycled and re-used. The environmental management measures suggested in the Environmental Management Plan (EMP) will be integrated into the drilling operations. PROJECT INVESTMENTS The overall cost involved in the exploratory drilling campaign would be around Rs. 66 Crores, i.e. about INR 33 Crores / Well. In the event of discovery of commercially viable hydrocarbon reserves, HOEC will propose further developmental strategies agreed by the Government under the PSC, considering the reservoir potential and market demand for hydrocarbons. K December