Will water scarcity in semiarid regions limit hydraulic fracturing of shale plays?

There is increasing concern about water constraints limiting oil and gas production using hydraulic fracturing (HF) in shale plays, particularly in semiarid regions and during droughts. Here we evaluate HF vulnerability by comparing HF water demand with supply in the semiarid Texas Eagle Ford play, the largest shale oil producer globally. Current HF water demand (18 billion gallons, bgal; 68 billion liters, bL in 2013) equates to similar to 16% of total water consumption in the play area. Projected HF water demand of similar to 330 bgal with similar to 62 000 additional wells over the next 20 years equates to similar to 10% of historic groundwater depletion from regional irrigation. Estimated potential freshwater supplies include similar to 1000 bgal over 20 yr from recharge and similar to 10 000 bgal from aquifer storage, with land-owner lease agreements often stipulating purchase of freshwater. However, pumpage has resulted in excessive drawdown locally with estimated declines of similar to 100-200 ft in similar to 6% of the western play area since HF began in 2009-2013. Non-freshwater sources include initial flowback water, which is <= 5% of HF water demand, limiting reuse/recycling. Operators report shifting to brackish groundwater with estimated groundwater storage of 80 000 bgal. Comparison with other semiarid plays indicates increasing brackish groundwater and produced water use in the Permian Basin and large surface water inputs from the Missouri River in the Bakken play. The variety of water sources in semiarid regions, with projected HF water demand representing similar to 3% of fresh and similar to 1% of brackish water storage in the Eagle Ford footprint indicates that, with appropriate management, water availability should not physically limit future shale energy production.