Injection of CO₂ for storage in a geologic formation increases pore pressure and alters in situ stresses. Depending on the orientation of any existing fault and fracture planes, such as critically stressed planes, this stress alteration will modify normal stresses acting on planes and could result in frictional sliding and release stored energy in the form of seismicity. Brine extraction (BE) is a technique that can be applied prior to, or during, CO₂ injection to reduce pore pressure for increasing storage capacity and, potentially, for reducing the likelihood of frictional sliding. A workflow is described to assess the efficacy of BE for mitigating frictional sliding (i.e., seismicity) during injection and entails: site characterization, stress calculations and failure assessment, static and dynamic modeling, and BE operational planning. Site characterization describes the stress field used to calculate the Coulomb Failure Function (CFF) that constrains allowable pore pressure changes and injection rates in the numerical simulation of CO₂ injection scenarios. The inclusion of BE in the workflow allows for determination of the potential need for pressure reduction, and evaluation of the effectiveness of this operation. Example application of the workflow using an injection field dataset near Decatur, IL, provides insight on fracture planes and stresses at the site, formation properties and the impact of variable CO₂ injection-rate targets on whether BE plans are required. The study workflow indicates that BE could enhance CO₂ injection rate by 39% and correspondingly reduce the potential for injection-induced seismicity as indicated by a reduction in CFF.

注入 CO ₂用于在地质层中储存会增加孔隙压力并改变地应力。根据任何现有断层和断裂平面的方向，例如临界应力平面，这种应力变化将改变作用在平面上的法向应力，并可能导致摩擦滑动并以地震活动的形式释放储存的能量。盐水提取 (BE) 是一种可以在 CO ₂之前或期间应用的技术注入以降低孔隙压力以增加存储容量，并可能降低摩擦滑动的可能性。描述了一个工作流来评估 BE 在注入过程中减轻摩擦滑动（即地震活动）的功效，包括：场地特征、应力计算和故障评估、静态和动态建模以及 BE 操作规划。场地特征描述了用于计算库仑破坏函数 (CFF) 的应力场，该函数限制了 CO ₂数值模拟中允许的孔隙压力变化和注入速率注入场景。在工作流程中加入 BE 可以确定潜在的减压需求，并评估此操作的有效性。使用伊利诺伊州迪凯特附近的注入场数据集的工作流示例应用提供了对现场裂缝平面和应力、地层特性以及可变 CO ₂注入率目标对是否需要 BE 计划的影响的见解。研究工作流程表明，BE 可以将 CO ₂注入率提高 39%，并相应地降低注入诱发地震活动的可能性，如 CFF 的减少所示。