Thermodynamic and Condensation Rate Modeling in Abandoned Wells: Assessing Potential Corrosion Risks in CCS Applications

Summary Carbon capture and storage (CCS) is considered one of the most suitable solution strategies for decarbonization in energy-intensive industries. While the examples of commercial-scale CCS projects are steadily growing worldwide, monitoring and success of such projects require mitigating several risks at the field scale. One of the challenges lies in assessing wellbore integrity issues in nearby abandoned wells, where wellbore corrosion caused by the condensation of acidic gases could be a potential integrity hazard. In this work, we develop a modeling framework to assess this issue by analyzing the underlying physical process of acid gas condensation through thermodynamics and heat transfer models to predict the acid gas condensation rates. We assess the effects of reservoir conditions of salinity, temperatures, and pressures on the resulting condensation rates, pH of the condensed liquid, and semi-empirically derived corrosion rates (CRs) across the well height. The study highlights the need to develop an assessment framework to identify and assess such integrity risks at an early stage for CCS projects.