Environmental Science & Technology · 2014 · 207 citations · 20 references
Natural ResourcesEarth SciencesWater Resources ManagementGroundwater ManagementHydraulic FracturingWater Resources EngineeringGroundwater BudgetGroundwater ConservationGroundwater Resource AssessmentWater ManagementWater Resource AssessmentWater Resources Impact AssessmentFluid Distribution Along Horizontal WellsHorizontal Well ProductionHydraulic Fracturing FluidsWater Availability AssessmentWater Consumption AccountingWater Resource AvailabilityWater Resource Cumulative Impacts
Hydraulic fracturing in the Barnett Shale raises concerns about water availability and impacts, with fresh surface water and groundwater used equally, and its long history is key to assessing the region’s water footprint. The study aimed to quantify hydraulic fracturing water volumes, sources, reuse, and disposal in the Barnett Shale. The authors compiled data from commercial, state, river authority, groundwater conservation district, and operator sources. From 1981 to 2012, hydraulic fracturing in the Barnett Shale used about 170,000 acre‑feet of water, with 2011 accounting for 32 % of Texas HF use and 0.2 % of state consumption; per‑well water use rose 60 % due to longer horizontal wells, though intensity fell 40 %, and produced water, which exceeds HF volumes and is largely injected, is inversely related to gas output.
Considerable controversy continues about water availability for and potential impacts of hydraulic fracturing (HF) of hydrocarbon assets on water resources. Our objective was to quantify HF water volume in terms of source, reuse, and disposal, using the Barnett Shale in Texas as a case study. Data were obtained from commercial and state databases, river authorities, groundwater conservation districts, and operators. Cumulative water use from ∼18 000 (mostly horizontal) wells since 1981 through 2012 totaled ∼170 000 AF (210 Mm3); ∼26 000 AF (32 Mm3) in 2011, representing 32% of Texas HF water use and ∼0.2% of 2011 state water consumption. Increase in water use per well by 60% (from 3 to 5 Mgal/well; 0.011–0.019 Mm3) since the mid-2000s reflects the near-doubling of horizontal-well lengths (2000–3800 ft), offset by a reduction in water-use intensity by 40% (2000–1200 gal/ft; 2.5–1.5 m3/m). Water sources include fresh surface water and groundwater in approximately equal amounts. Produced water amount is inversely related to gas production, exceeds HF water volume, and is mostly disposed in injection wells. Understanding the historical evolution of water use in the longest-producing shale play is invaluable for assessing its water footprint for energy production.
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