Near-Wellbore Water Imbibition Study for Cyclic Injection of CO2 into the Subsurface

Abstract The present work constitutes a comprehensive study on near-wellbore water imbibition in the context of CO2 cyclic injection for storage purposes. The research, conducted at INEOS Energy and DTU Chemistry, aims to provide a deeper understanding of the imbibition process and its implications for CO2 cyclic injection practices. It uses two simulation cases, modeled in Eclipse (SLB), starting from a relatively simple Black Oil model and inductively moving to a more complex compositional one. The models are two-phase, isothermal, homogeneous, and consist of a horizontal injection well and a vertical cross-section around it. Some of the most impactful parameters of the near-wellbore water imbibition process are investigated to enhance knowledge of the industrial approach of Project Greensand. Initially, the concept of CO2 cyclic injection and its potential as a tool for reducing greenhouse gas emissions are introduced. Then there are references to the key theoretical concepts around CO2 injection and expected results based on previous studies. Numerical simulations are used to investigate the dynamics of water imbibition near the wellbore during CO2 cyclic injection. The results of these numerical models are analyzed in detail, revealing key insights into the mechanisms of water imbibition and the factors that affect its rate and extent. Continuing, the impact of various parameters, such as injection rate, saturation function hysteresis, brine salinity, and well location, on near-wellbore water imbibition is examined. The findings of this study, which show how key simulation parameters affect water imbibition, have significant implications for the optimization of CO2 cyclic injection processes, contributing to enhanced operational efficiency and sustainability in the energy industry. Overall, this work provides a valuable contribution to the field of engineering, offering a deeper understanding of the complex dynamics of near-wellbore water imbibition during CO2 cyclic injection. The insights gained from this study have the potential to inform and improve industry practices, leading to more efficient approaches to the application of a crucial decarbonization technology.