Potential Advances in the Design of Sealants for Geologic Conformance Control toward CO₂ Storage Security

The global warming crisis, traceable to the rise in greenhouse gas emissions, has called for more proactive measures to curb the emission levels. To this effect, several technologies have been suggested. Out of the lot, carbon capture, utilization, and storage have been identified as one of the most feasible and pragmatic methods. This is partly because the concept, technical resources, and facilities are transferable from CO₂ injection and enhanced oil recovery applications. For this reason, studies centered around CO₂ conformance control for subsurface storage have been conducted. Also, reviews on the classification and description of chemical materials utilized for the conformance control have been published. With the limitations of these materials in mind, this review extends the types of sealants that can be applied for CO₂ entrapment in subsurface geologic formations. The group of gelants that generally fall under multicomponent polymer systems and viscoelastic fluids was evaluated. The review describes their properties, behavior, response to CO₂, and other unique features that make them suitable to be considered for reservoir conformance control purposes. Based on the review, recommendations for future studies on these novel materials were given.