The Application of Produced Water Treatment and Water Blending in Shale Resource Development

Transcription

1 The Application of Produced Water Treatment and Water Blending in Shale Resource Development Authors: J. D. Arthur, P.E., SPEC; and David Alleman New York Water Environment Association 2013 Spring Technical Conference and Exhibition Syracuse, New York June 3 6, 2013

2 The Future of Shale Horizontal Drilling and HVHF have revolutionized U.S. oil and gas production. Natural gas production has increased 15% in 5 years Several sources suggest that US oil production could rise 50-75% over the next 10 years, causing imports to drop to 5%. As the pace of drilling continues to rise, we can expect: Increased use of brackish/saline water Increased use of treatment technologies Increased reliance on re-use of produced water and much more... Another study suggests the shale gas boom will account for ~1.5 million new jobs by 2015 (June 2012) even with the current downturn in gas prices. Some economists expect cumulative investments of ~$3.2 trillion from 2012 through June

3 Technology: The Game Changer Horizontal drilling & HF 3-D seismic analysis Multi-well drilling pads Water Characterization Water sourcing, staging, conditioning and transport Ample disposal options Impact mitigation Logistics & waste mgmt Cost reductions Source: June 2013 Copyright (c) 2012 ALL Consulting 3

4 HYDRAULIC FRACTURING Horizontal wells completed in the Marcellus use about t45m 4.5 million gallons of water for hydraulic fracturing Water is obtained from various sources and delivered by truck or pipeline Water is stored in tanks or centralized impoundments 10 to 30 % (or more) of the fracture fluid is recovered June

5 Lifecycle Water Management Planning Pre-Development Assessment Water Sourcing Availability & Issues Well Site Construction & Drilling Water Conditioning/Pre-Treatment Well Completion/Fracturing Flowback/Produced Water Reuse/Disposal/Beneficial Use A lifecycle approach is needed to address the many issues important to industry: Regulatory timing & vulnerabilities Legislative changes Public opposition Historical Activities Competition for resources Flowback recovery Third-party options and risks Environmental risks Cumulative Impacts Etc June

6 WATER NEEDS / AVAILABIILTY June

7 Water: An Array of Considerations Logistics: Methods for transporting water and resultant wastes can carry wide variations in costs, liabilities, resource production, manpower, community relations, and environmental implications. Sourcing: Choosing options for sourcing that is best suited to a particular play or region is critical. Storage: A key aspect to the feasibility of many options, especially for groundwater, reuse/recycling, blending, etc. Treatment: Treatment adds costs and creates waste. To use treatment, economic thresholds must be achieved. Disposal/Reuse: Options are generally driven by the character of a play or region. Compliance/Monitoring: Critical aspect of managing water! June

8 WATER USE FOR SELECT PLAYS (2011) Minimum Reported Water Usage (gal.) Maximum Reported Water Usage (gal.) Average Reported Water Use (gal.) Well Sample Shale Basin/Play Barnett 1,004,556 11,970,504 3,961,550 1,247 Bakken 1,005,064 9,597,540 2,101, Eagle Ford 1,098,846 13,659,790 4,295,282 1,523 Fayetteville 1,730,415 11,282,621 5,294,829, 456 Haynesville 1,023,414 14,850,612 5,824, Marcellus/Utica 1,006,004 10,781,652 4,423,310 1,514 Woodford 1,017,828 11,782,600 4,181,

9 WATER USE VARIES SPATIALLY

10 Higher water volumes are more common in the western portion of the Eagle Ford play Variations Within a Single Play Some Shale plays can be rather expansive, covering large portions of a state or even multiple states. This means practices specific to any number of issues may vary greatly even within a single development area. Lesser volumes of water are more predominant in the eastern portion of the play Data Source: FracFocus & ALL Consulting (2012) June

11 Fresh Water Facts Relative Use: Most discussion of water includes little in the way of relative use or actual cumulative impacts relative to availability. Comparative Use: Most unconventional plays will amount to a fraction of one (1) percent of overall uses in a region. Availability: Access to fresh water (surface or groundwater) is generally preferred as it is most desired by landowners (in general), offers adequate capacity, is the least expensive option, and offers the best results for drilling & fracturing. Alternatives: Other options often do not provide the same results and are more expensive - thus decreasing economic viability. June

12 WATER SOURCING June

13 Water Sourcing Choosing options for sourcing that are best suited to a particular play or region is critical. Traditional water sources include fresh water from: Surface waters such as rivers, lakes, and ponds Groundwater To reduce demands on fresh water, some operators are turning to alternate sources of water such as: Re-use of produced water Saline aquifers POTWs Acid mine drainage June

14 Use of Alternate Water Sources Use of alternate water sources can have significant benefits Reduce demands on fresh water resources Reduce disposal volumes Reduce truck traffic Reduce environmental risks Reduce costs Etc. Two key considerations Blending: need to understand what happens to water quality when multiple sources are mixed Treatment: Some level of treatment is typically required June

15 Produced Water Quality and Volume Shale Play Produced Water TDS Concentration (mg/l) Percent of Fracture Fluid Volume Typically Recovered During Flowback Barnett 40, , % Eagle Ford 10, , % Fayetteville 8,000 30, % Haynesville 150, , % Marcellus 50, , % Utica 40, , % December 2012 Copyright (c), ALL Consulting

16 Reuse of Produced Water Reuse: In several areas, water reuse "may" be critical to acquiring ample water for drilling and fracturing (although justification can vary). Challenges: Water produced after fracturing often contains high levels of bacteria, metals, and salt compounds that present challenges for reuse. Blending: Prior efforts were generally limited to settling, fresh water blending, and filtration (as early as ~2001). However, this approach requires greater quantities of chemical additives. Treatment: Treating high levels of bacteria as well as corrosion and scale inducing constituents has been employed to facilitate reuse of produced water starting from about 2008 in the Woodford and Fayetteville Shale areas. June

17 Characteristics of Fracturing Fluid TDS can vary to 100,000+ ppm Scaling compounds Iron: remove suspended iron, reduce soluble iron to < 500 ppm Barium: reduce to <20 ppm or control scaling Other - Multivalent cations and anions reduce to < calculated scaling index Oil carryover (O & G) < 50 ppm, prefer < 30 ppm. Bacteria to <1000 cells/ml, spikes to 10,000 acceptable. TSS less than 500 ppm of 105 micron and larger solids Effective fracturing fluid; chemical and/or physical treatment to deactivate or remove deleterious substances

18 Groundwater (Source A) Produced Water Groundwater (Source B) Engineered (Blended) Water Surface Water WATER BLENDING & SCALE AFFINITY June

19 Blending Water with a Purpose! Water Sourcing may originate from multiple sources and include produced water Storage and blending may be done in tanks or multi-well fluid management pits Transportation via trucks and/or pipeline Water is used rapidly for activities like fracturing Reuse and disposal is a key aspect of the water management lifecycle Water Storage & Conditioning Water Sourcing Rapid Use for Drilling and/or Fracturing June

20 The Water Blending Model Uses an established and verified aqueous geochemical model developed by the US Geological Survey (PHREEQC). Allows user to input multiple source water compositions The program predicts speciation formation through the calculation of saturation-indices. Model reacts mixed water solutions by allowing water chemistry to come to equilibrium on select species and then allows user to use that reacted water in subsequent modeling. Model outputs: Reports on water quality changes from mixing prognosis Provides both simple mix and reacted water qualities Graphs on changes in Water Quality due to mixing Reports on precipitating and/or dissolving minerals due to mixing Results of mixing model are transferred to the Scale Affinity Model June

21 Scale Affinity Indices Calculated Skillman Index Analysis for CaSO 4 Scale Model Limited to Temp of 25 o C Larson-Skold Index Addresses Chlorides, Sulfates, and Alkalinity Developed for Great Lakes quality cooling water Ryznar Stability Index Analysis for CaCO 3 Scale Multiple interpretation regimes Ryznar Interpretation(1942), Carrier Interpretation (1965) Puckorius Scaling Index Analysis for CaCO 3 Scale Langelier Saturation Index Analysis for CaCO 3 Scale TDS Limit <10,000 ppm Total Hardness <4,000 ppm Stiff-Davis Stability Index Analysis for CaCO 3 Scale Works for TDS >10,000 ppm Temp Limit <90 o C Oddo-Tomson Scale Index Analysis for CaCO 3 Scale Corrects for multiple phases (water, gas, and oil) Model limits Temp to 25 o C Aggressive Index Analysis for CaCO 3 Scale Driving Force Index Analysis for CaCO 3 Scale June

22 Mixed Water Composition Output Example Mixed Water Quality Outputs Scale Model Output Example Mineral Saturation Indices Example Outputs June

23 WATER TREATMENT June

24 Reasons to Treat Produced Water Discharge Beneficial Use Reuse Reduce disposal volume June

25 Treatment of Produced Water for Reuse Regardless of the source of water, operators need to ensure that the hydraulic fracturing fluid is effective Water quality requirements for hydraulic fracturing can vary and may depend on factors such as: Composition of the target formation The specific chemicals being used (especially friction reducers) Selection of treatment technologies depends on: Characteristics of water being treated Treatment goals Common treatment goals Remove suspended solids Prevent scale formation and bio-fouling Reduce dissolved solids (desalination) Reduce disposal volumes June

26 Solids Removal Suspended Solids Removal Settling: Oxidation and precipitation Chemical flocculation, precipitation Electro coagulation enhanced Desanders and hydrocyclones Auto flush sand filters Membrane filtration: micro, ultra, nano pores Applications Precipitates iron, removes scale, polymers, bacteria Remove dispersed solids including scale Remove suspended solids and some ions Remove particles to 50 microns Remove particles to about 50 microns Remove particulates to 1 micron June

27 Scale and Micro-Organism Control Scale removal / imbibition Scale control with chemical addition Oxidation ozone, chloro-oxidants Settling and filtering Adsorption IX resins, activated carbon Bacteria removal / destruction Biocides addition UV light treatment Oxidation - Ozone, chloro compounds June

28 Desalination and Relative Cost Desalination Reverse / forward osmosis Thermal vaporization Vapor recompression & crystallization Applications Low salinities to 40,000 ppm, removes TDS, and is sensitive to operate High salinities (50, ,000 ppm), yields nearly distilled water and sensitive to operate June

29 Key Considerations Oil and Gas from shale is an important source of energy for the U.S. Large volumes of water are necessary for production UIC disposal options are limited in some areas Treatment can conserve source water and reduce waste stream Treatment is more than desalination Reuse is an increasingly important option Treatment technologies are advancing and changing

30 Contact Information David Alleman Senior Environmental Manager ALL Consulting 1718 S. Cheyenne Ave. Tulsa, OK Citation Information: Arthur, J.D., and D. Alleman (ALL Consulting). The Application of Produced Water Treatment and Water Blending in Shale Resource Development Presented at the New York Water Environment Association 2013 Spring Technical Conference and Exhibition, Syracuse, New York, June 3-6, June