화학공학소재연구정보센터
Energy & Fuels, Vol.34, No.11, 14464-14475, 2020
Aqueous CO2 Foam Armored by Particulate Matter from Flue Gas for Mobility Control in Porous Media
Carbon dioxide (CO2) is injected into reservoirs for enhanced oil recovery worldwide, which is an important technology to reduce carbon emissions from burning and consumption of fossil fuels. However, it is difficult to control the mobility of carbon dioxide in the formation, thus limiting its extensive utilization. In this work, particulate matter (PM) from flue gas was used to obtain an interfacial armored foam for controlling the CO2 mobility in porous media. Both homogeneous and heterogeneous porous model experiments were adopted to study CO2 foam flow behavior in porous media. Furthermore, the viscosity, interfacial viscoelasticity, and microstructure of foam were measured to help understand the mobility control mechanism. The results showed that the interfacial adsorption and compression of PM formed a particle armor on the CO2-liquid interface, which improved foam film roughness and changed the interface to be more solid-like. Consequently, the viscosity of CO2 foams was increased by 2-13 times with the addition of 1.2 wt. % PM. In pore scale, the PM armored foams had stronger Jamin resistance and slipping resistance than bare surfactant foam. Thus, they showed relatively low mobility in porous media. The CO2 gas channel and water breakthrough were inhibited by the injection of 1 PV armored foams. The armored foams showed a higher resistance to the water flushing during the subsequent water flooding. The use of bare PM dispersions did not establish an effective flow resistance in the porous media. However, when a lower CO2 content (20% foam quality) was co-injected with the liquid phase, the improvement of foam resistance factor by adding PM was about 3 times upon addition of PM. Moreover, in the heterogeneous porous model, the mobility of fluids in the high permeability sandpack was effectively controlled by the armored foam, thus increasing the sweeping efficiency in the medium and low permeability sandpacks. Compared with bare surfactant foam flooding, the oil recovery by using armored foam was increased by about 21.3%. After flooding with armored foams, the residual resistance factors of armored foams were reduced to a lower level by enough subsequent water flooding, indicating the temporary plugging and low damage of armored foams in porous media. The significance of this research is the utilization of two important atmospheric pollutants by an inexpensive Pickering foam method for petroleum development and carbon sequestration.