Enhanced Oil Recovery Using Aqueous CO2 Foam Stabilized by Particulate Matter from Coal Combustion

Carbon dioxide (CO2) foam flooding is a promising carbon capture, utilization, and storage technology that is often used for enhanced oil recovery (EOR). However, the instability of foam and low displacement efficiency restrict its efficient utilization. In this work, the microflow behavior and the EOR performance of aqueous CO2 foam stabilized by particulate matter (PM) from coal combustion were systematically studied using a micromodel with etched porous media. The results showed that, when a moderate camellia oleifera saponin (COS) concentration was used, the addition of PM could transfer the maximum foam volume to a higher temperature. Moreover, with the addition of PM, the half-life of CO2 foam drainage could be increased by similar to 12 times at 75 degrees C. The disproportionation, coalescence, and film rupture of CO2 foams in the porous media slowed down in the presence of PM. At high water cut stage, the different types of microresidual oil, such as cluster, columnar, membrane, and blind-end, could effectively be activated and displaced by the PM/COS foam. During the flooding, the high stability of PM/COS foam in the presence of oil guaranteed the efficiency of the whole process. The solid-like foam film enhanced the plugging effect in the water channel. The rough surface of the PM/COS bubble with high interfacial viscoelasticity enhanced the scrubbing capacity of the bubble to residual oil. According to the sandpack flooding results, the recovery of oil increased by similar to 40.85% due to the injection of PM/COS foam and subsequent water at 60 degrees C, which was about twice of the oil recovery obtained using pure surfactant foam.