Understanding the Factors Affecting the Adsorption of Surface-Active Agents onto Reservoir Rock in Chemical Enhanced Oil Recovery Applications: A Comprehensive Review

This comprehensive review delves into the recent advancements in the study of surfactant adsorption, a crucial factor influencing the efficiency of chemical enhanced oil recovery (cEOR) applications across various oil types. By integrating findings from the latest literature, we shed light on the dynamic interactions between surfactants and diverse adsorbents including sandstone, carbonate, and shale sandstone. This review highlights the nuanced understanding of how operational variables such as initial surfactant concentration, pH, adsorbent dose, contact time, temperature, along with adsorption kinetics, isotherm models, thermodynamics, and the presence of competing ions, contribute to the adsorption process. A novel synthesis of recent studies reveals that the Langmuir and pseudo-second-order models continue to accurately describe the equilibrium and kinetics of adsorption in most scenarios, with the adsorption process predominantly exothermic. Additionally, this review introduces cutting-edge insights into the molecular-level mechanisms underpinning surfactant adsorption, emphasizing the role of crude oil components, initial wettability of reservoir rocks, and the intrinsic properties of the rock itself. By summarizing these contemporary findings, the review aims to provide a deeper understanding of the key parameters affecting the retention of surface-active agents on various adsorbents, thereby proposing new avenues for optimizing surfactant flooding in cEOR. This enhanced focus on recent contributions to the field distinguishes our review from existing literature, offering fresh perspectives on the optimization of surfactant use in oil recovery processes.