Paper No. 175-7
Presentation Time: 10:10 AM
MANAGING WATER ISSUES RELATED TO UNCONVENTIONAL OIL AND GAS PRODUCTION IN THE US (Invited Presentation)
Unconventional oil and gas production plays an increasingly important role in U.S. production, accounting for ~60% of oil and ~70% of gas production in the U.S. in 2018. However, there are increasing concerns about adverse environmental impacts related to water management, including water depletion, induced seismicity, and water contamination. In this study, we analyzed water issues related to unconventional energy extraction focusing on regional analyses: (a) to meet exponentially rising water demand for hydraulic fracturing (HF), and (b) to manage rapidly growing volumes of water co-produced with oil and gas (produced water, PW). We analyzed past (2009–2017) volumes of water for HF and PW in ~80,000 wells and projected future water volumes in major tight oil and shale gas plays in the U.S.. Results show that water use for HF markedly increased, depleting groundwater resources in some semiarid regions, particularly the western Eagle Ford play in Texas with groundwater level declines up to 46 ft [14 m]/yr. Projected water demand for HF regionally exceeds planned groundwater supplies in parts of the semiarid Permian and Eagle Ford plays. Most PW is generated by oil reservoirs with the Permian tight oil reservoir producing ~18 times more water than the Marcellus/Utica shale gas reservoirs. PW is projected to increase exponentially in the Permian which may result in increased induced seismicity if managed primarily using subsurface disposal. Water concerns related to projected exponential growth in both water demand for HF and PW supplies, especially in semiarid tight oil plays, may be partially resolved by reusing PW for HF in new wells. However, projected volumes of PW exceed water demand for HF in the Permian, especially the Delaware Basin by almost four times, with this basin accounting for ~50% of projected oil production in the U.S.. Therefore, water issues may limit energy production in the future, especially in semiarid tight oil plays.