Spatial and Temporal Variabilty in Produced Water in Texas: Implications for Management

Bridget Scanlon, Robert C. Reedy, Svetlana Ikonnikova, and Qian Yang Bureau of Economic Geology Jackson School of Geosciences University of Texas at Austin

Texas Groundwater Protection Committee Basic Questions

Data Types • Geology, hydrology • Reservoir data • Well completions • Production

Historical Trends Future Projections Impacts • HF water • Play lifetime HF, PW • Water scarcity • Produced water • 2018-2035 Outlook • GW depletion • PW management

Mitigation PW reuse for HF Water Use for Hydraulic Fracturing

Cumulative hydraulic Bakken 2009-2017 Billion gal fracturing volume is highest in the Permian 49 Marcellus-Utica Niobrara 28

96 Oklahoma Fayetteville 64 24 Hydraulic Fracturing Barnett 34 130 Haynesville Permian 30 Eagle Ford 110 Thickness and Drilling in Primary Producing Intervals in Permian Basin

Thickness of Wolfcamp A & B units in Midland and Delaware basins in the Permian Basin and horizontal wells by year. Total Water Use for Hydraulic Fracturing by Play

70 HF water use increased by ~ 10× in ) 250 ) yr

60 yr Permian Basin (2011 – 2017), growth phase L/ gal/ 200 9 9 50 HF water use peaked in many plays in 2014, (10 (10 reflects ↓ drilling since then, related to oil 40 150 price drop 30 100 High HF water use in Permian reflects 20 increased drilling + rising HF water intensity 50 10 Total HF water use Total HF water use 0 - 2009 2011 2013 2015 2017 Total Lateral Length Drilled HF water use/foot of lateral

30 3.5 8 40 25 m)

ft) 3.0 6 ft ) 6

20 2.5 /m)

6 30 3 2.0

15 gal/ (1000 4 1.5 20 10 2 1.0

5 10 HF water use (m Total lateral length (10 Total lateral length (10 HF water use 0.5 0 0 2009 2011 2013 2015 2017 0.0 0 2009 2014

Lateral length drilled peaked in 207 in Permian HF water use/foot of lateral in Permian and 2014 in many other plays increased by 4× 2011 – 2017; ~300% Water use for Hydraulic Fracturing as a % of Total Water Use in the Play

Fayetteville Haynesville HF Water Use as % of Total Barnett Water Use Marcellus/… Niobrara Bakken Eagle Ford Permian

0 10 20 30 40 50 60 HF water use (109 gal/yr) or % total water use Water use (WU) for hydraulic fracturing (HF, maximum annual) ranges from 4% to 22% of total water use (TWU; USGS 2015) in play areas, excluding mining. Major and Minor Aquifers in the Permian Basin Groundwater Management Depth of Rig, Frack, and Industrial Wells Number of Wells drilled to supply Hydraulic Fracturing by Aquifer Groundwater Quality Groundwater Quality Impacts of Groundwater Pumping on Groundwater Levels Pecos (Permian) Eagle Ford 2000 2003 2006 2009 2012 2015 2018 2000 2003 2006 2009 2012 2015 2018 0 0 0 0 4644501 Reeves County Pecos Valley Aquifer 10 100 627 ft (191 m) deep unused 50 50 well 20 200 WL decline 2.6 ft/yr (0.8 m/yr) 100 >2010 30 300 7738103 100 40 400 La Salle County Carrizo-Wilcox Aquifer Depth Depth to water (ft)

150 Depth to water (ft) Depth Depth to water (m) 50 Depth to water (m) 500 Stock well 150 2,084 ft deep; 46 ft/yr (14 m/yr) 600 200 60

GW declines in the Delaware Basin could impact surface water. Large GW declines in the western portion of the Eagle Ford play. HF demand: ~5,000 Bgal over life of Bakken the play in the Permian (Wolfcamp A 57,000 wells Projected HF water & B units) 370 Projected water availability based on demand:- Billion managed depletion: ~300 Bgal/yr gal If the ~300,000 HF wells are drilled over 50 yr HF water use = ~30% of projected 1,900 managed available groundwater

Midland Basin 2,800 106,000 wells

Hydraulic 710 Delaware Basin fracturing 192,000 wells Eagle Ford 87,000 wells Basic Questions

9.4 480 Oklahoma Fayetteville

Barnett 74 Produce 180 Haynesville d Permian SaltWater water 16 disposal Eagle Ford 61 Produced Water Volume in Plays

70 250 60 Oklahoma PW volume ↑ 30 times in 200 50 Permian Basin (2011 – 2017)

40 150 30 Oil plays produce much 100 more water than gas plays 20 Total PW (BL/yr) Total PW (Bgal/yr) 50 10

0 - 2009 2011 2013 2015 2017 Permian Basin

Total Oil Production Total Produced Water

1.5 1.5 ) yr / 1.0 1.0 Bbbl (

0.5 0.5 Total PW PW Total Total oil prodTotal (Bbbl/yr) 0.0 0.0 2009 2011 2013 2015 2017 2009 2011 2013 2015 2017

Permian Midland Delaware Permian Midland Delaware

Oil production in Midland and PW in Delaware Basin = ~2× that in Midland Delaware Basins are similar Basin in 2017 PW in Delaware Basin = 3 × oil production (2017) Produced water is mostly managed using Saltwater Disposal Wells Bakken Marcellus/Utica

740 wells

Permian

1,750 wells Haynesville

Eagle Ford 250 wells

336 wells Induced seismicity highest in OK attributed to deeper disposal Bakken and larger volumes relative to Bakken, Permian, and Eagle Ford

Marcellus/ Utica Fayetteville

OK Permian Haynesville Barnett

Eagle Ford Earthquake Events ≥ Magnitude 2 (monthly data; USGS Source)

25 500

20 400

15 300 Events in OK 10 200

Number of Events 5 100

0 0 Number of 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 Permian Eagle Ford Barnett

Seismicity increasing in the Permian and Eagle Ford plays Bakken Projected Totals - Billion gal 57,000 wells

590

10,300 2,800 Midland Basin Delaware Basin 106,000 wells 192,000 wells 240

Eagle Ford Produced 87,200 wells Water Basic Questions

• Flowback and produced waters have complex matrices, high salinity, many waters exceeding seawater salinity • These waters contain inorganic and organic chemicals from formation waters in addition to chemical additives from hydraulic fracturing, naturally occurring radioactive materials, and heavy metals • Common analytical approaches for surface water and groundwater are not suitable for flowback and produced waters • Oetjen et al., 2017 Basic Questions

70 250 60 200 50 HF water use L/yr) gal/yr) 9

9 40 150

30 100 Volume 10 Volume

Volume (10 Volume 20 50 10

0 0 2009 2010 2011 2012 2013 2014 2015 2016 2017 2009 2010 2011 2012 2013 2014 2015 2016 2017 2009 2010 2011 2012 2013 2014 2015 2016 2017 2009 2010 2011 2012 2013 2014 2015 2016 2017 2009 2010 2011 2012 2013 2014 2015 2016 2017 2009 2010 2011 2012 2013 2014 2015 2016 2017

Eagle Ford Bakken Marcellus-Utica Midland Delaware Oklahoma

HF > PW PW ↑ rel HF >> PW HF > PW PW = 2 HF PW>>HF to HF 2016 PW >> HF in Delaware Basin Bakken limits potential for reuse of PW 57,000 wells Projected Totals - Billion gal 590

2,800 10,300

Midland Basin Hydraulic 106,000 wells fracturing Produced 240 Water (PW) Delaware Basin 192,000 wells Eagle Ford 87,000 wells PW >> HF in Delaware Basin Bakken limits potential for reuse of PW 57,000 wells Projected Totals - Billion gal 370 590

2,800 1,900

2,800 Midland Basin Hydraulic 10,300 106,000 wells fracturing Produced 240 Water (PW) Delaware Basin 710 192,000 wells Eagle Ford 87,000 wells Basic Questions

1. How much water is used for hydraulic fracturing (source and quality of water)? 2. How much water is produced with oil and gas and how is it managed? 3. What is the quality of produced water? 4. Can we reuse produced water for hydraulic fracturing? 5. Can we treat produced water for use in other sectors? Water requirements for different sectors • Potable water, EPA regulations for major, trace, and organic constituents • Primary inorganic standards of concern: Fl (4 mg/L), Ra226+Ra228 combined (5 pico Curies, pCi/L), and U (30 ug/L). • Secondary inorganic standards of concern: TDS (500 mg/L), Cl (250 mg/L), SO4 (250 mg/L), Fl (2 mg/L), and Fe (0.3 mg/L) • These regulations were developed considering general surface water and groundwater quality but do not include regulations for many of the potentially harmful constituents in flowback and produced water Water Quality Requirements for Agriculture • Livestock watering: TDS up to 10,000 mg/L • Elements of potential concern: arsenic (As; 0.2 mg/L), boron (B; 5.0 mg/L), and fluoride (2.0 mg/L). NORMs also an issue. • Irrigation: • TDS: <175 mg/L (excellent, Class 1); 175–525 mg/L (good, Class 2), 525–1,400 mg/L (permissible with leaching, Class 3), and 1,400–2,100 mg/L (doubtful, particularly for sensitive plants (Class 4) • Sodium Adsorption Ratio: = + / 𝑁𝑁𝑁𝑁 +2 +2 • SARs > 3 require additional𝑆𝑆𝑆𝑆𝑆𝑆 flushing; 𝐶𝐶SARs𝐶𝐶 +> 𝑀𝑀𝑀𝑀13 can2 degrade soil structure • SARs from USGS database: 0.7 – 28.5 (water samples from conventional reservoirs) • SARs in Williston Basin ~15 – 16. • Boron (B) is also an issue: B tolerance varies with crop type: wheat (0.75 – 1.0 mg/L), sorghum and alfalfa (4 – 6 mg/L), and cotton (6 – 15 mg/L) Reduction in Total Dissolved Solids in Produced Water • Reverse Osmosis can remove TDS in waters with TDS up to 47,000 mg/L • Remove up to 99% NaCl; Si and B require additional treatment, can remove radionuclides, pretreatment recommended for removal of organics and scale, recovery 30 – 60% • Thermal approaches can be used with water up to 300,000 mg/L TDS • Thermal distillation can be used with any level of TDS, (heat and evaporate feedwater followed by condensation of pure water)

• 100% rejection of Na, SiO2, B, and heavy metals. • Multistage Flash Distillation (< 40,000 mg/L TDS; recovery 10 – 20%, scale inhibitors and acids, no biocides required [high T]) • Multiple Effect Distillation (MED) (scaling issues, 20 – 35% recovery) • Vapor Compression Distillation (VCD) (can be used with TDS > 40,000; can be used as crystallizer resulting in zero liquid discharge) • High energy requirements (waste heat available) PW treatment costs increase with higher salinity in PW and product water quality improvement

Separation Removal of target Post-treatment of oil, Desalination - constituents (e.g., and grease, organics, Fe, Ba, Removal of dissolved restabilization suspended Ca, Mg, Sr, SiO2, solids (e.g., B) solids SO4, microbes)

• Hydrocyclone • Biological • Gas flotation treatment >125 • Oil/Water • Electrocoag. & separator flotation E • Settling tank • Adsorption 10 M m • Media (carbon, 0 V e filtration zeolite, etc) R r 75 (sand, walnut • Chemical g shell, etc) oxidation M i • Cartridge • Disinfection V n C g 50 filtration (ClO2, UV, etc) • Membrane F filtration S M O • Ion Exchange Applicable TDS range (g/L) B W 2 W E • AOP N R 5 E R D M • pH adjust.& remineral. F O D D O • Disinfection (Cl2, UV)

Clean Industrial Agricultural Groundwater Brine for Uses Uses recharge, potable HF uses Treatment Options for Produced Water

• Fit for purpose treatment • Minimal treatment for HF because of changes in HF water quality requirements (filtering, TSS, biocides, Fe, Mn) • Desalination plants (Marcellus, interest in Permian Basin) • Use of high quality PW for irrigation (CBM, CA) Salt from Concentrate

• Permian Basin Example • 273x106 m3 of SWD • 100,000 mg/L TDS = 100 kg salt/m3 of water • Density of NaCl 2170 kg/m3 • 100 (kg salt/m3) / 2170 (kg salt/m3 of salt) x 273x106 m3 SWD • 12.6 x 106 m3 salt in 2015 • 10,300 acre feet of salt in 2015 Comparison of Water Supplies from Produced Water with Water Demand in Different Sectors

barrel = 0.16 m3 Comparison between Produced Water Supply versus Water Demand for Hydraulic Fracturing: Permian Basin (2015 data)

1,000

SWD

bbl/yr) 100 6

10 Volume (10 1 Lea Culb… Croc… Midl… How… Irion Andr… Reag… Eddy Wink… Glass… Ector Ward Pecos Crane Upton Loving Martin Reeves Produced water supply is based on volumes disposed in salt water disposal wells (SWD) HF: hydraulic fracturing water demand Infrastructure to store and transport produced water

Martin

Midland Glasscock

Upton Reagan Contamination from Produced Water (Texon Scar) Contamination in Delaware Basin, artesian well

mg/L Lake Well Lake/Well TDS 94,700 6,250 15.2 Ca 2,000 640 3.1 Mg 395 193 Boehmer 2.0 Lake Na 35,200 1,130 31.2 K 50 18 2.8 Cl 53,600 1,840 29.1 SO4 3,110 2,020 1.5 HCO3 448 762 0.6 F 1.19 2.05 0.6

Spills in Permian Main Conclusions

1. How much water is used for hydraulic fracturing (source and quality of w 20% of water in the Permian and Eagle Ford plays, increasing volumes being stabilizing recently. Fresh and brackish GW. No reports on reuse/recycling. 2. How much water is produced with oil and gas and how is it managed? Permian: 14 bbl water/bbl oil (conventional), ~ 3 bbl water/bbl oil (unconven Mostly managed using EORI for conventonal reservoirs and SWD for unconve reservoirs. 3. What is the quality of produced water? Variable: Permian highest salinity in shallow zone near salt deposits, higerh q depth. 4. Can we reuse produced water for hydraulic fracturing? Yes, in most plays. Delaware Basin and some others produce more water tha for hydraulic fracturing. 5. Can we treat produced water for use in other sectors? Yes, high salinity will require thermal distillation. Lot of salt generated. Project Sponsors:

Shell-UT Unconventional Research

Contact: Bridget Scanlon [email protected] References

• Ikonnikova, S. A., F. Male, B. R. Scanlon, R. C. Reedy, and G. McDaid (2017), Projecting the Water Footprint Associated with Shale Resource Production: Eagle Ford Shale Case Study, Environmental Science & Technology, 51(24), 14453-14461. • Nicot, J. P., and B. R. Scanlon (2012), Water Use for Shale-Gas Production in Texas, US, Envir. Sci. & Technol. , 46(6), 3580-3586. • Oetjen, K., C. G. S. Giddings, M. McLaughlin, M. Nell, J. Blotevogel, D. E. Helbling, D. K. Mueller, and C. P. Higgins (2017), Emerging analytical methods for the characterization and quantification of organic contaminants in flowback and produced water, Trends in Environmental Analytical Chemistry, 15(Supplement C), 12-23. • Scanlon, B. R., R. C. Reedy, F. Male, and M. Walsh (2017), Water Issues Related to Transitioning from Conventional to Unconventional oil Production in the Permian Basin, Environmental Science & Technology, 51(18), 10903-10912. • Scanlon, B. R., M. B. Weingarten, K. E. Murray, R. C. Reedy, and S. A. Ikonnikova (2018), Managing Basin- Scale Fluid Budgets to Reduce Injection-Induced Seismicity from the Recent U.S. Shale Oil Revolution, Report submitted to the Mitchell and Sloan Foundation. • Scanlon, B. R., R. C. Reedy, and J. P. Nicot (2014), Will water scarcity in semiarid regions limit hydraulic fracturing of shale plays?, Environmental Research Letters, 9, DOI 10.1088/1748-9326/9/12/124011, 9(12). • Scanlon, B. R., R. C. Reedy, and J. P. Nicot (2014), Comparison of water use for hydraulic fracturing for unconventional oil and gas versus conventional oil, Environmental Science & Technology, 48(20), 12386- 12393.