Table_1_Revisiting Geologic Storage Potential in Unconventional Formations Is Key to Proactive Decision Making on CCS in India.DOCX

Global energy modeling exercises project significant deployment of CO2 capture and storage (CCS) to bridge the gap between India's pledged climate commitments and the 1. 5°C target. Despite advances in laboratory analyses and process modeling, the information on geologic storage potential in India is limited. Prior studies indicate that the vast majority of storage potential exists in saline aquifers (50–300 Gt-CO2); though, this might be overestimated. These estimates also estimate the theoretical potential in coal seams to be <5 Gt-CO2 while shale basins have not been evaluated as geologic CO2 sinks on a systems level. Based on several recent climate developments and CCS best practices, we suggest revisiting these potential estimates. We demonstrate how revisiting some assumptions might enhance the coal repository available as a sink by a factor of 7–8. We also present proof-of-concept analysis to show that Indian shale reservoirs might have suitable CO2 adsorption capacity. With detailed recommendations for revising these estimates, we present a methodological framework for incorporating the best practices for coal seam and shale basin storage potential. Based on source-sink mapping exercises, we also argue that unconventional basins in India are especially relevant because of their proximity to large point sources of CO2.

全球能源建模研究显示，为弥合印度既定气候承诺与1.5℃温控目标之间的差距，需大规模部署二氧化碳捕集与封存（CCS）技术。尽管实验室分析与过程建模技术已取得长足进展，但印度境内地质碳封存潜力的相关信息仍较为有限。既往研究表明，绝大多数碳封存潜力集中于盐水层（50~300 Gt-CO₂），但该估算值或存在高估情况。上述估算同时指出，煤层的理论碳封存潜力不足5 Gt-CO₂，而页岩盆地尚未在系统层面被评估为地质二氧化碳汇。基于近期多项气候发展态势与CCS最佳实践，我们建议重新审视上述碳封存潜力的估算结果。本研究证实，调整部分核心假设可将煤层碳汇的可用容量提升7~8倍。此外，我们通过概念验证分析表明，印度页岩储层或具备适宜的二氧化碳吸附能力。结合针对修正上述估算的详细建议，我们提出了一套方法学框架，用于纳入煤层与页岩盆地碳封存潜力评估的最佳实践标准。通过源汇映射研究，我们同时指出，印度非常规油气盆地因紧邻大型二氧化碳点源，其碳封存价值尤为凸显。