Challenges with managing unconventional water production and disposal in the Permian Basin

Produced water (PW) associated with oil and gas production from unconventional reservoirs in the Permian Basin has the potential to constrain future production if not managed effectively. The objective of this work was to report trends in produced and disposed water volumes and to highlight disposal capacity challenges and implications for future development. We compiled production and disposal data from public and commercial databases, focusing on the Midland and Delaware Basins. Results show that annual PW volumes from unconventional wells in the Permian Basin increased by a factor of 30 from 2010 to 2022. Unconventional PW volumes in 2022 totaled approximately 5 billion bbl, with 70% from the Delaware Basin and 30% from the Midland Basin. This increase reflects increasing numbers of horizontal wells drilled (approximately 6000 in 2022), lateral lengths (approximately 2 mi in 2022), and water to oil ratios (averaging 3.3 in 2022 and up to 10 locally). Currently, almost all PW from unconventional production is managed by disposal into strata shallower (75%) or deeper (25%) than producing intervals. Adverse impacts of disposal include induced seismicity linked mainly to deep disposal, drilling hazards related to overpressuring in shallow disposal zones, compromised integrity of older vertical wellbores, and surface discharges of PW. Increasing PW recycling for hydraulic fracturing would improve management in the Midland Basin, where PW and hydraulic fracturing volumes are currently similar, but large excesses of PW (3.6 times hydraulic fracturing demand) in the Delaware Basin will remain a challenge, necessitating development of alternative water management strategies.