Can we beneficially reuse produced water from oil and gas extraction in the US?

There is increasing interest in beneficial uses of large volumes of wastewater co-produced with oil and gas extraction (produced water, PW) because of water scarcity, potential subsurface disposal limitations, and regional linkages to induced seismicity. Here we quantified PW volumes relative to water demand in different sectors and PW quality relative to treatment and reuse options for the major U.S. shale oil and gas plays. PW volumes from these plays totaled similar to 600 billion liters (BL, 160 billion gallons, Bgal) in 2017. One year of PW is equal to similar to 60% of one day of freshwater use in the U.S. For these plays, the total irrigation demand exceeded PW volumes by similar to 5x whereas municipal demand exceeded PWby similar to 2x. If PW is reused for hydraulic fracturing (HF) within the energy sector, there would be no excess PW in about half of the plays because HF water demand exceeds PW volumes in those plays. PW quality can be highly saline with median total dissolved solids up to 255 g/L in the Bakken play, similar to 7x seawater. Intensive water treatment required for PW from most unconventional plays would further reduce PW volumes by at least 2x. Desalination would also result in large volumes of salt concentrates, equivalent to similar to 3000 Olympic swimming pools in the Permian Delaware Basin in 2017. While water demands outside the energy sector could accommodate PW volumes, much lower PW volumes relative to water demand inmost regions would not substantially alleviate water scarcity. However, large projected PW volumes relative to HF water demand over the life of the play in the Permian Delaware Basin may provide a substantial new water source for beneficial use in the future. Large knowledge gaps in PW quality, lack of appropriate regulations, and economic factors currently preclude beneficial uses outside the energy sector in most regions. (c) 2020 The Authors. Published by Elsevier B.V.