Hennings Peter, Staniewicz Scott, Smye Katie, Chen Jingyi, Horne Elizabeth, Nicot Jean-Philippe, Ge Jun, Reedy Robert, Scanlon Bridget
Bureau of Economic Geology, Jackson School of Geosciences, The University of Texas at Austin, P.O. Box X, Austin, TX 78713-8924, United States of America.
Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, TX 78713-8924, United States of America.
Sci Total Environ. 2023 Dec 10;903:166367. doi: 10.1016/j.scitotenv.2023.166367. Epub 2023 Aug 24.
The Delaware Basin in west Texas and southeast New Mexico is now the largest global oil producing basin, averaging ∼400,000 m (∼2,500,000 barrels) per day in 2022. The shale-dominated strata targeted for production can co-produce 4-5 times more water than oil, necessitating disposal by injection of ∼1,400,000 m (∼8,700,000 barrels) of water per day in 2022. Through a comprehensive assimilation of regional Sentinel-1 satellite radar data and analysis of production and injection, we show how petroleum operations have caused the development of complex and accelerating patterns of surface deformation from 2015 through 2021. We observe uplift from reservoir swelling, subsidence from reservoir contraction, and the development of linear features that are indicative of faulting. Subsidence is predominantly caused by production, and an important finding of this study is that the magnitude of subsidence is linearly proportional to total production. Uplift is caused by pressurization from wastewater injection of shallow permeable strata. The patterns of uplift are complex and extend laterally well-beyond areas where injection was performed. Linear surface deformation features are observed throughout the Delaware Basin, and they are lengthening and densifying as uplift and subsidence accelerate. Many of the lineations can be linked to known strata-bounded faults and shallow seismicity in the southern Delaware Basin where they serve as permeable and anisotropic conduits for pore pressure migration. In the Northern Delaware Basin, co-seismic rupture is hosted along basement-rooted faults that may link to the linear surface features. Understanding these dynamic changes in Delaware Basin is a pressing concern for management of subsurface reservoirs and safeguarding the surface environment. Concerns include ongoing induced seismicity, hazard of drilling through over-pressured strata, maintenance of integrity for newer wellbores, mitigation of flows of brine and petroleum fluids at the surface of old wellbores, and management of the pore space resource for wastewater injection.
位于得克萨斯州西部和新墨西哥州东南部的特拉华盆地，目前是全球最大的产油盆地，2022年日均产量约为40万立方米（约250万桶）。以页岩为主的目标生产层产出的水比石油多4至5倍，这使得2022年每天需要注入约140万立方米（约870万桶）的水进行处置。通过全面同化区域哨兵-1卫星雷达数据以及对生产和注入情况的分析，我们展示了2015年至2021年期间石油作业如何导致了复杂且加速的地表变形模式的发展。我们观察到储层膨胀导致的隆起、储层收缩导致的沉降，以及表明断层活动的线性特征的发展。沉降主要由生产活动引起，本研究的一个重要发现是沉降幅度与总产量呈线性比例关系。隆起是由浅层可渗透地层废水注入产生的压力所致。隆起模式复杂，横向延伸范围远超注水区域。整个特拉华盆地都观察到了线性地表变形特征，随着隆起和沉降加速，这些特征在变长且变密集。许多线性特征可与特拉华盆地南部已知的地层边界断层和浅层地震活动联系起来，在那里它们充当孔隙压力迁移的可渗透且各向异性的通道。在特拉华盆地北部，同震破裂发生在基底扎根的断层沿线，这些断层可能与线性地表特征相关。了解特拉华盆地的这些动态变化是地下储层管理和保护地表环境的紧迫问题。这些问题包括持续的诱发地震活动、钻穿超压地层的风险、新井筒完整性的维护、老井筒表面盐水和石油流体流动的缓解，以及废水注入孔隙空间资源的管理。
