This paper presents a workflow for delineating a risk-based area of review (AOR) to support a US Environmental Protection Agency (EPA) Class VI permit for a carbon dioxide (CO₂) storage project. The approach combines semianalytical solutions for estimating formation fluid leakage through a hypothetical leaky wellbore with the results of physics-based numerical reservoir simulations. The workflow is demonstrated using a case study for a hypothetical 180,000-metric-ton-per-year storage project located in the Plains CO₂ Reduction (PCOR) Partnership region, which includes all or part of 10 states in the United States and four Canadian provinces. Under the scenario where the leaky wellbore is open to a saline aquifer (thief zone) between the overlying seal (cap rock) and the underground sources of drinking water (USDW), the risk-based AOR is no larger than the areal extent of the CO₂ plume in the storage reservoir because the pressure buildup in the storage reservoir beyond the CO₂ plume is insufficient to drive formation fluids up a hypothetical leaky wellbore into the USDW. However, even under the conservative assumption that the leaky wellbore is not open to a thief zone, the incremental leakage beyond the areal extent of the CO₂ plume is less than 400 m³ over 20 years. The approach outlined in this paper is designed to be protective of USDWs and comply with the Safe Drinking Water Act requirements and provisions for the EPA Class VI Underground Injection Control (UIC) Program (Class VI Rule) and North Dakota Administrative Code Chapter 43-05-01. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.

中文翻译：

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超压储层中基于风险的审查估计区域，以支持二氧化碳封存项目的注入井封存设施许可要求

本文介绍了一个工作流程，用于划定基于风险的审查区域 (AOR)，以支持美国环境保护署 (EPA) 二氧化碳 (CO ₂ ) 封存项目的VI 级许可证。该方法将通过假设的泄漏井筒估算地层流体泄漏的半解析解决方案与基于物理的储层数值模拟结果相结合。该工作流程使用位于平原 CO ₂的假设年 180,000 公吨存储项目的案例研究进行演示减少 (PCOR) 伙伴关系区域，包括美国 10 个州的全部或部分地区和加拿大的四个省。在泄漏井筒对上覆密封层（盖层）和地下饮用水源（USDW）之间的咸水层（窃贼区）开放的情况下，基于风险的 AOR 不大于该区域的面积范围。储存油藏中的CO ₂羽流，因为超出 CO ₂羽流的储存油藏中建立的压力不足以将地层流体沿假设的泄漏井筒向上推入 USDW。然而，即使在泄漏井眼不通向窃贼区的保守假设下，超出 CO ₂羽流区域范围的增量泄漏也小于 400 m ³超过 20 年。本文中概述的方法旨在保护 USDW 并符合安全饮用水法案的要求和 EPA VI 类地下注入控制 (UIC) 计划（VI 类规则）和北达科他州行政法规第 43-05 章的规定-01. © 2021 化学工业协会和 John Wiley & Sons, Ltd.