Regulatory oversight of a geologic carbon sequestration (GCS) project relies on iterative estimations, throughout the project lifetime, of the area where increased risks to underground sources of drinking water (USDWs) may occur due to injection of CO₂. This area, referred to as Area of Review (AoR), is typically delineated by predicting the migration of fluid between the reservoir and the lowermost USDW via an open wellbore using predictions from physics-based reservoir simulators. The inherent uncertainty in input parameters used in reservoir modeling therefore affects the accuracy of determining the AoR for a project. Furthermore, the standard analytical approaches for calculating a critical pressure to delineate the risk area yield an infinite AoR for cases where the injection reservoir is overpressured relative to the USDW. A methodology is presented here to better characterize the risk to USDWs while accounting for the uncertainty in reservoir modeling, with an application to a permitted GCS project with an overpressured injection formation, FutureGen 2.0. The methodology is demonstrated using the National Risk Assessment Partnership’s open-source integrated assessment model (NRAP-Open-IAM) to develop a probabilistic estimate of impact risk to USDW quality. CO₂ and pressure predictions from the reservoir modeling conducted using the STOMP-CO₂ simulator for the FutureGen 2.0 site are used in a NRAP-Open-IAM model with reservoir, wellbore, and aquifer components to: (1) assess the extent of potential leakage into the USDW for the predicted reservoir pressure conditions; (2) evaluate the extent of potential impact using “no-net-degradation” thresholds; and (3) account for uncertainty in reservoir permeabilities.

地质碳固存（GCS）项目的监管监督依赖于整个项目生命周期中对由于注入CO ₂而可能增加地下水源（USDWs）风险的地区进行的迭代估算。。通常通过使用基于物理的油藏模拟程序的预测，通过一个裸眼井筒来预测油藏与最低USDW之间的流体迁移，来描绘该区域，称为“复查区域（AoR）”。因此，在储层建模中使用的输入参数固有的不确定性会影响确定项目AoR的准确性。此外，用于计算临界压力以划定危险区域的标准分析方法可在注入储层相对于USDW超压的情况下产生无限的AoR。本文介绍了一种方法，可以更好地描述USDW的风险，同时考虑储层建模的不确定性，并应用于带有超压注入地层的准GCS项目FutureGen 2.0。使用国家风险评估合作伙伴关系的开源综合评估模型（NRAP-Open-IAM）演示了该方法，以开发对USDW质量的影响风险的概率估计。一氧化碳₂和使用STOMP-CO ₂模拟器对FutureGen 2.0站点进行的储层建模压力预测在具有储层，井眼和含水层成分的NRAP-Open-IAM模型中用于：（1）评估潜在泄漏的程度将USDW用于预测的储层压力条件; （2）使用“无网络退化”阈值评估潜在影响的程度；（3）解释了储层渗透率的不确定性。