Assessing the effects of different gas types on stability of SiO2 nanoparticle foam for enhanced oil recovery purpose

Application of silica nanoparticles (SiO2-NPs) as a foamer in CO2 foams has been widely investigated. Investigating the role of SiO2-NPs on making and stabilizing foams created by various gas types is still ongoing. This research attempted to experimentally determine and compare the impacts of SiO2-NPs on the stability of foams created by various available gas types including Nitrogen (N2), Methane (CH4), and carbon dioxide (CO2). For this purpose, 0.12 wt% Sodium dodecyl sulfate was solved in NaCl solution 0.1 wt% and then SiO2-NPs at concentrations from 0.001 to 0.1 wt% were added to the solution. N2, CH4, and CO2 gases were injected to the NPs suspensions with a flow rate of 50 mL/min and the stability of generated foams was determined through measuring half-life time. Once the optimum NP concentration was found for each gas type, that foam was flooded to a sandpack to find and compare the amount of oil recoveries. The optimum concentration of SiO2-NPs in terms of foam stability was achieved 0.01 wt% for all the applied gas. The half-life time of CH4, N2, and CO2 foams at 0.01 wt% SiO2-NPs were achieved 1054, 1720, and 62 min, respectively. Besides that, the amounts of incremental oil recoveries by NP-CH4, NP-N2, and NP-CO2 foams were obtained 25%, 31%, and 19%, respectively that 2 to 6% were higher than foam flood tests without NPs. According to the obtained results, it is generally can be concluded that utilizing N2 and CH4 gases in foam flooding for EOR purpose is more efficient than CO2.