Source and fate of hydraulic fracturing water in the Barnett Shale: a historical perspective.
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 Mm(3)); ∼ 26 000 AF (32 Mm(3)) 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 Mm(3)) 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 m(3)/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.