Study of a high salt-resistant foam reinforced by sodium bentonite particles

Foam flooding has been widely used as an effective technology to enhance oil recovery. As a thermodynamically unstable system, foam is prone to disproportionation and coalescence especially in high-salt or high-temperature environments, which limits the effective plugging performance in complex reservoirs. In this paper, a commercial anionic-nonionic compound surfactant was used as the foaming agent, and low-cost sodium bentonite, which is optimized from three types of inorganic particles, was used as the foam stabilizer. The compound system has a foaming volume of 605 mL and a half-life of 1260 s under the environment of 90 °C and 271207 mg/L. The Nano Measurer software is proposed to calculate the foam diameter under different conditions. Furthermore, the effect of salinity, temperature, foaming agent, and stabilizer concentration on foam properties were investigated, and the mechanism of sodium bentonite on foam stability was explored. This study may provide some experimental basis and theoretical explanation for the development of particle-stabilized foam.