Injection-induced seismicity across the US midcontinent has almost exclusively occurred in the crystalline basement that underlies the Arbuckle Group aquifer and its equivalents, the primary wastewater disposal zone in this region. However, the properties of the basement are not well known. Newly compiled data, from Class I wells in Kansas, provide a unique record of pressures in the Arbuckle and an opportunity to constrain the reservoir-scale properties of the basement such as permeability, diffusivity, and specific storage. Constraints on these parameters are critical for modeling fluid flow and pressures across the entire Arbuckle-basement system, and are necessary for accurate evaluation and prediction of injection-induced earthquakes. Here, we present a detailed, three-dimensional geological and pressure history-matched numerical model for the Arbuckle and basement, based on data from >400 wells covering a large region in south-central Kansas, where injection-induced seismicity has been concentrated since 2014. Simulations of dynamic data from 319 wells indicate that Arbuckle pressures have increased by 1.1 MPa in high injection rate areas and an overpressure of <0.1 MPa may be the cause of seismicity in the basement. Pressure-history matching also yields the likely range in porosity (0.3%–7%), permeability (0.1–0.7 mD), and diffusivity (0.004–0.07 m²/s) for the basement. The resulting estimates suggest reservoir-scale properties of the basement are enhanced by faults and fractures. Importantly, the diffusivities determined in this study are lower than estimates derived from Kansas earthquake triggering fronts, and suggest that such seismicity-based techniques may have limitations, particularly where space-time patterns between injection and seismicity are complex.

中文翻译：

---

来自压力历史匹配的前寒武纪结晶基底特性及其对美国中部大陆诱发地震的影响

美国中部大陆的注入引起的地震活动几乎完全发生在位于 Arbuckle Group 含水层及其等效层（该地区的主要废水处理区）之下的结晶基底中。然而，地下室的属性并不为人所知。来自堪萨斯州 I 级井的最新汇编数据提供了阿巴克尔压力的独特记录，并有机会限制基底的储层规模特性，例如渗透率、扩散率和特定存储。对这些参数的约束对于模拟整个 Arbuckle 基底系统的流体流动和压力至关重要，并且对于准确评估和预测注入诱发的地震也是必不可少的。在这里，我们为您详细介绍，Arbuckle 和基底的三维地质和压力历史匹配数值模型，基于覆盖堪萨斯州中南部大片区域的 400 多口井的数据，自 2014 年以来注入诱发的地震活动一直集中在该地区。 319口井表明，高注入区Arbuckle压力增加了1.1 MPa，<0.1 MPa的超压可能是基底地震活动的原因。压力-历史匹配还得出孔隙度 (0.3%–7%)、渗透率 (0.1–0.7 mD) 和扩散率 (0.004–0.07 m) 的可能范围 319口井的动态数据模拟表明，高注入区Arbuckle压力增加了1.1 MPa，<0.1 MPa的超压可能是基底地震活动的原因。压力-历史匹配还得出孔隙度 (0.3%–7%)、渗透率 (0.1–0.7 mD) 和扩散率 (0.004–0.07 m) 的可能范围 319口井的动态数据模拟表明，高注入区Arbuckle压力增加了1.1 MPa，<0.1 MPa的超压可能是基底地震活动的原因。压力-历史匹配还得出孔隙度 (0.3%–7%)、渗透率 (0.1–0.7 mD) 和扩散率 (0.004–0.07 m) 的可能范围² / s) 用于地下室。由此产生的估计表明，断层和裂缝增强了基底的储层规模特性。重要的是，本研究中确定的扩散率低于堪萨斯州地震触发前沿的估计值，并表明这种基于地震活动的技术可能存在局限性，尤其是在注入和地震活动之间的时空模式复杂的情况下。