A Study of Microscale Gas Trapping Using Etched Silicon Micromodels

摘要: Immobilization and trapping of carbon dioxide (CO2) enhances the security geological storage. Trapping mechanisms have been characterized in four groups: structural, residual, dissolution, mineralization. While structural acts immediately when injection starts is well investigated, contribution residual dissolution increases over storage time these contributions need to be better understood for predictions. This paper focuses on an experimental pore-scale investigation capillary trapping. CO2–water imbibition experiments were conducted micromodels whose homogenous pore space geometrically topologically similar Berea sandstone. Microvisual data, photographs video footage, describes mechanism and, especially, disconnection shrinkage CO2 phase. Results show that depending flow rate imbibing water different are observed. Lower rates, comparable trailing edge a plume, lead more snap-off events greater trapped saturation, whereas rates near wellbore area during enhanced sequestration showed displacement gas bubbles ultimately leads very low or zero saturations. Furthermore, complete as heterogeneous occurs. Whereas latter subdivided into microbubble formation crevices roughness, former occurs without influence walls. Based observations we suggest type rock its roughness fines present at brine interface important factors determining mechanism.