Bureau of Economic Geology, Jackson School of Geosciences, University of Texas at Austin, Austin, Texas 78758, United States.
Environ Sci Technol. 2020 Mar 17;54(6):3510-3519. doi: 10.1021/acs.est.9b06390. Epub 2020 Mar 3.
The rapid growth in U.S. unconventional oil and gas has made energy more available and affordable globally but brought environmental concerns, especially related to water. We analyzed the water-related sustainability of energy extraction, focusing on: (a) meeting the rapidly rising water demand for hydraulic fracturing (HF) and (b) managing rapidly growing volumes of water co-produced with oil and gas (produced water, PW). We analyzed historical (2009-2017) HF water and PW volumes in ∼73 000 wells and projected future water volumes in major U.S. unconventional oil (semiarid regions) and gas (humid regions) plays. Results show a marked increase in HF water use, and depleting groundwater in some semiarid regions (e.g., by ≤58 ft [18 m]/year in Eagle Ford). PW from oil reservoirs (e.g., Permian) is ∼15× higher than that from gas reservoirs (Marcellus). Water issues related to both HF water demand and PW supplies may be partially mitigated by closing the loop through reuse of PW for HF of new wells. However, projected PW volumes exceed HF water demand in semiarid Bakken (2.1×), Permian Midland (1.3×), and Delaware (3.7×) oil plays, with the Delaware oil play accounting for ∼50% of the projected U.S. oil production. Therefore, water issues could constrain future energy production, particularly in semiarid oil plays.
美国非常规油气的快速增长使能源在全球范围内更加充足和廉价，但也带来了环境问题，尤其是与水有关的问题。我们分析了能源开采的与水有关的可持续性，重点关注：（a）满足水力压裂（HF）迅速增长的用水需求，（b）管理与石油和天然气（伴生水，PW）一起大量产生的水。我们分析了约 73000 口井中历史（2009-2017 年）HF 水和 PW 量，并预测了美国主要非常规石油（半干旱地区）和天然气（湿润地区）地区未来的用水量。结果表明，HF 水的使用量显著增加，一些半干旱地区的地下水位正在下降（例如，在鹰福特地区每年下降≤58 英尺[18 米]）。油藏（例如，二叠纪）产生的 PW 约比气藏（马塞勒斯）高 15 倍。通过将 PW 循环再用于新井的 HF 来部分缓解与 HF 水需求和 PW 供应有关的水问题。然而，在半干旱的巴肯（2.1 倍）、二叠纪米德兰（1.3 倍）和特拉华（3.7 倍）油区，预计 PW 量超过 HF 水需求，其中特拉华油区占预计美国石油产量的约 50%。因此，水问题可能会限制未来的能源生产，特别是在半干旱的石油产区。
