Water Quality, Quantity, and Management: Lessons from the Marcellus Shale Region

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Presentation by Radisav D. Vidic,
University of Pittsburgh, for a hydrofracking forum hosted by the Cary Institute of Ecosystem Studies in Millbrook, NY on May 5, 2012.

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Water Quality, Quantity, and Management: Lessons from the Marcellus Shale Region

  1. 1. Water Quality, Quantity, andManagement: Lessons from the Marcellus Shale Region Radisav D. Vidic, PhD, PE Department of Civil and Environmental Engineering University of Pittsburgh civil and environmental engineering
  2. 2. Shale Gas Basins civil and environmental engineering
  3. 3. Hydrofracturing civil and environmental engineering
  4. 4. Water Supply Issues• Need 2 to 6 Million gallons of water per well for hydraulic fracturing• Surface Water Withdrawals – Concerns about depletion of water resources, especially in drought years – Impacts to aquatic life – Ability to get withdrawals approved – Don’t really need high quality water, but consistent quality is important• Transportation of water – 1 MG = 200 trucks – Cost can be significant (up to $2/bbl)• Water storage on site civil and environmental engineering
  5. 5. Water Withdrawal in PA• Need 2 to 6 Million gallons of water per well for a multi- stage hydrofracturing Water-use category Water withdrawal Percentage (MGD) (%) Public supply 1420 15 Domestic 152 1.6 Irrigation 24.3 0.3 Livestock 61.8 0.6 Aquaculture 524 5.5 Industrial 770 8.1 Mining 95.7 1 Thermoelectric power plants 6430 67.7 Marcellus Shale exploitation in 2013 18.7 0.2 (Gaudlip et al. 2008) civil and environmental engineering
  6. 6. Water Use in PAMarcellus Shale Play is not a significant water user in PA civil and environmental engineering
  7. 7. Water Transfer Issues- Trucks- Temporary surface lines- Permanent subsurface lines civil and environmental engineering
  8. 8. Water Storage IssuesStorage options:• Centralized impoundment— now becoming more prominent• Single pad- dedicated impoundment• Frac tanksStorage based on ultimate scale of operations (long vs. short term) civil and environmental engineering
  9. 9. Volumetric Composition of Fracking Fluids civil and environmental engineering
  10. 10. Fracture Fluid CompositionAdditive type Main Compound PurposeDiluted acid (15%) Hydrochloric or Dissolve minerals and initiates Muriatic cracks in rockBiocide Glutaraldehyde, DBNPA Bacterial controlCorrosion inhibitor N,n-dimethyl Prevents corrosion formamideBreaker Ammonium persulfate Delays breakdown of gel polymersCrosslinker Borate salts Maintains fluid viscosity at high temperature Polyacrylamide Minimize friction between theFriction reducers fluid and the pipe Mineral oilGel Guar gum or Thickens water to suspend the hydroxyethyl cellulose sand civil and environmental engineering
  11. 11. Fracture Fluid CompositionAdditive type Main Compound PurposeIron control Citric acid Prevent precipitation of metal oxidesOxygen scavenger Ammonium bisulfite Remove oxygen from fluid to reduce pipe corrosionpH adjustment Potassium or sodium Maintains effectiveness of other carbonate compounds (e.g., crosslinker)Proppant Silica quartz sand Keeps fractures openScale inhibitor Ethylene glycol Reduce deposition on pipeSurfactant Isopropanol Increase viscosity of fluid civil and environmental engineering
  12. 12. Latest Fracture Fluid DesignsSand Additives5.56% 0.08% Water Additives 94.36% Anti- Friction microbial reducer 37% 50% Scale inhibitor 13% civil and environmental engineering
  13. 13. Anatomy of a Vertical WellMarcellus Shale wells are casedand grouted (using specialcements) to prevent migration ofnatural gas and fluid from theproducing zone up the well boreinto fresh-water aquifers. civil and environmental engineering
  14. 14. Wastewater Issues Flowback water Produced waterFlowrate High Low (10-50 bbl/day)Duration 1 – 2 weeks Life of the wellTDS < 200,000 mg/L > 300,000 mg/L Chemical additives Same as flowback but moreComposition Naturally occuring constituents salts Water recovery 10 – 40 % Flowrate varies with location civil and environmental engineering
  15. 15. Wastewater Storage IssuesStorage options:• Centralized impoundment• Single pad- dedicated impoundment• Frac tanks Environmental Risks - Leakage - Erosion and sediment control civil and environmental engineering
  16. 16. Flowback Water Characterization 160 flowback water analyses (BOGM, MSC, etc.) 3(1) 18(8) 14(10) 29(15) 29(15) 4(1) 2(1) 7(3) 2(2) 1(1) 26(4) 4(2) 1(1)15(3) 23(5) 8(3) 3(3) civil and environmental engineering
  17. 17. Flowback Water QualityConstituent Low Medium High Ba (mg/L) 2,300 3,310 13,500 Sr (mg/L) 1,390 2,100 8,460 Ca (mg/L) 5,140 14,100 41,000 Mg (mg/L) 438 938 2,550Hardness (mg 17,900 49,400 90,337/L as CaCO3) TDS (mg/L) 69,400 175,600 345,000 Gross Beta ND 43,415 597,000 (pCi/L)Ra226 (pCi/L) ND 623 9,280COD (mg/L) 850 12,550 36,600 civil and environmental engineering
  18. 18. Flowback Water Management• Wastewater disposal - Injection/disposal wells - Disposal to dedicated treatment facilities - Discharge to POTWs civil and environmental engineering
  19. 19. Gas Drilling Wastewater Management (Hart, P., 2011) civil and environmental engineering 19
  20. 20. Disposal Wells• Require demonstration that injected fluids remain confined and isolated from fresh water aquifers• Limited capacities (1200 to 3000 bpd)• Substantial capital investment with uncertain life span ($1M to $2M)• Probably will only play a limited role• Depleted shallower wells are currently being evaluated!?!? civil and environmental engineering
  21. 21. Microseismic Tests in Marcellus Shale civil and environmental engineering
  22. 22. Dedicated Treatment Facilities civil and environmental engineering
  23. 23. Impact on Surface Water Quality civil and environmental engineering
  24. 24. Impact on Surface Water Quality CROOKED CREEK & McKEE RUN Bromide Concentration (ppb) Oct Nov Dec Jan Feb March April May June July Aug Sept Oct Sample Site 2010 2010 2010 2011 2011 2011 2011 2011 2011 2011 2011 2011 2011McKee Upstream of Plant B 29 79 61 36 27 17 32 66 93 63 26 25 Run Donwstream of Plant B 20 X 10 X 9X 10 X 1.1 X 3X 3X 8X 8X 27 X 34 X 4X 17X Blue Spruce Bridge 57 39 64 87 37 38 13 53 83 116 114 56 25Crooked Creek Bridge St. Bridge 1130 345 639 774 42 111 44 414 640 3100 3900 214 427 Stitt Hil Rd. Bridge 280 467 396 173 74 53 112 258 578 582 426 103 (Casson, L., 2012) civil and environmental engineering
  25. 25. Disposal to POTWs• Chosen option in the past• POTWs use biological processes• Biological systems cannot handle high salinity (few case studies above 35,000 mg/L)• Require an approved pretreatment program civil and environmental engineering
  26. 26. Treatment for Reuse in Fracking Operations• Reduce O&G industry needs for surface water• Reduce overall management costs – Volume reduction – Transportation costs – Disposal costs• Reduce potential liability civil and environmental engineering
  27. 27. Water Bank Concept• Reuse difficult for smaller operators – Insufficient well count – Insufficient capital• Develop rules for water banking – Smaller operator dispose of their wastewater in regional impoundments – Larger operators get credit for water reuse and pollution elimination civil and environmental engineering
  28. 28. Recycling/Reuse • 4800 wells on 625 mi2 • 3 refractures/well • 33% water reuse - Works for 12-15 yrs - Eventually we are a net producer of water civil and environmental engineering
  29. 29. Total Water Balance Within a Gas Field (Kujivenhoven et al., 2011) civil and environmental engineering 29
  30. 30. Treatment Options 100 CrystallizersWater Recovery (%) Evaporation 75 Limited recovery at high TDS 50 25,000 50,000 100,000 300,000 Total Dissolved Solids (mg/L) civil and environmental engineering
  31. 31. Complete Treatment Process FLOWBACK WASTE WATER FRAC BRINESOURCE OPERATIONS PRODUCED STORAGE WATER RECOVERED WATER Pretreatment ROAD BRINE BRINEDEICING CRYSTALLIZER CONCENTRATOR Volume SALT Reduction Based on TDS PURGE TO 95% Volume DISPOSAL Reduction civil and environmental engineering
  32. 32. Gas Drilling Wastewater Management (Hart, P., 2011) civil and environmental engineering 32
  33. 33. Salt production in Marcellus region• 100,000 wells• 10 barrels/day/well of produced water• 300,000 mg/L salinity of produced water• 80% salt recovery• Total NaCl produced in PA = 8 million tons• Total salt use for deicing in the US = 12-15 million tons civil and environmental engineering
  34. 34. AMD in Pennsylvania• Pennsylvania’s single greatest source of water pollution – Contaminated 4,000 miles of streams• Elevated levels of iron and sulfate• Can have elevated hardness• TDS typically around 1,000 mg/L• May be suitable as fracking water make up with little or no treatment civil and environmental engineering
  35. 35. Why AMD?Permitted wells Abandoned discharge Reclaimed discharge civil and environmental engineering
  36. 36. Co-treatment of flowback water and AMD Flowback water Abandoned mine drainage (AMD) Barium, Strontium, Calcium Sulfate Hydraulic fracturingEnables the reuse of flowback water for hydraulic fracturing withlimited treatment => decreases the treatment and transport cost of flowback water civil and environmental engineering 36
  37. 37. Summary• Marcellus shale development hinges on documenting environmental impacts and developing sustainable water management• Almost no direct disposal options and limited treatment options for flowback/produced water• Flowback water reuse appears to be the most effective option• Water reuse has a finite lifetime• Salt management may become a major issue in PA• AMD is a promising/convenient water source for hydraulic fracturing civil and environmental engineering
  38. 38. Thank You forYour Attention Questions? civil and environmental engineering
  39. 39. Natural Gas Production Source: Annual Energy Outlook, EIA, 2011 civil and environmental engineering
  40. 40. History of Hydrofracturing• First test in 1903• First commercial use in 1949• More than 1,000,000 wells by 1998• Nowadays, 35,000 wells per year with new technology civil and environmental engineering
  41. 41. Well PadMadden 2H, Lycoming County civil and environmental engineering
  42. 42. Multiwell Pads civil and environmental engineering
  43. 43. Rapid Marcellus Development civil and environmental engineering
  44. 44. Typical Efficiencies of Thermoelectric Power Plants Source: Stilwell et al., 2009 civil and environmental engineering
  45. 45. Water Use in Thermoelectric Power Plants civil and environmental engineering
  46. 46. Flow scheme 1: Conventional Water Management Flowback “Fresh” Class II Well Water Disposal Well 1  Represents Maximum Water Demand (No Water Reuse)  Conventional approach in Barnett and other plays  Difficult in Marcellus (only 7 Class II wells) civil and environmental engineering
  47. 47. Flow scheme 2: On-Site Primary Treatment for Reuse On-Site Settling SS & FR Rem Well 1 High TDS Reuse Water Blend Makeup Water (Fresh Water) Well 2 civil and environmental engineering
  48. 48. Flow scheme 3: Off-Site Primary Treatment for Reuse Sedimenta- On-Site Rapid Mix tion & Hard- Rapid Sand Settling w/ Caustic Filter ness Rem SS Removal & Flocculant Well 1 Near-Field Disinfect Belt Press Primary (Ozone or Treatment Peroxide) Solids to Landfill High TDS Water For Reuse Blend Makeup Water (Fresh Water) Well 2 civil and environmental engineering
  49. 49. Flow scheme 4: Off-Site Primary Treatment and Demineralization Demineral- Concentrated On-Site Near Field Ization Brine Settling SS Removal Primary Treatment Mechanical Well 1 Vapor Recomp Disposal (Class II Well) Or By-Product Recovery Distilled Water (Crystallizer) For Reuse Blend Makeup Water (Fresh Water) Well 2 civil and environmental engineering
  50. 50. Economic Comparison of Flow SchemesBasis: 1 million gallons of flowback (23,800 barrels) Flow Scheme FS 1 FS 2 FS 3 FS4 Method Transport to “In Field” Primary “Near Field” “In-Field” Class II Well Treatment Precipitation Evaporation for Disposal for Reuse for Reuse for Reuse Treatment $ - 71 83 119 Transport $ 75 1 24 24 Brine Disposal $ 60 - - 19 Sludge Disposal $ - 2 6 6 Total Cost ($x1000) 135 74 113 168 Cost per barrel 5.67 3.10 4.75 7.05 Hardness Removal 100% 0% 97% 100% Ba removal 100% 0% 99% 100% Salt Removal 100% 0% 0% 100% Water reused 0 99% 97% 90% civil and environmental engineering
  51. 51. Geosteering civil and environmental engineering
  52. 52. Resource Development 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 1 2 3 4 5 6 7 8 910111213141516171819202122232425 civil and environmental engineering

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