A comparative analysis of the effect of nanoparticles/surfactant assisted foam injection on the gas mobility control at different heterogeneities

Abstract

Foam flooding is a popular method for increasing oil recovery in reservoirs with varying levels of heterogeneity. One common foam flooding technique is surfactant-assisted foam flooding (SF), which uses surfactants to create stable foam. However, SF is limited in high-pressure, high-temperature, and high-salinity reservoirs. To overcome these limitations, researchers have proposed a new approach called nanoparticles-assisted foam flooding (NAF), which involves adding nanoparticles to improve surfactant properties. While SF has been shown to improve sweep efficiency in heterogeneous reservoirs, the potential benefits of NAF are not fully understood. In this study, researchers investigated the performance of SF and NAF in controlling gas mobility in reservoirs with different levels of heterogeneity. They defined heterogeneity levels using sequential Gaussian simulation with varying standard deviation values. They also included a gas–water flooding (GW) scenario as a baseline. The results showed that SF effectively delayed breakthroughs and improved recovery factors in highly heterogeneous reservoirs. The researchers also compared normalized values of breakthrough time, breakthrough recovery factor, and recovery factor after 50 years for SF and NAF, which were normalized by corresponding GW results. Simulation results showed that SF and NAF could increase the normalized breakthrough time (SF: 10–17%, NAF: 12–42%), breakthrough recovery factor (SF: 11–20%, NAF: 16–53%), and recovery factor after 50 years (SF: 0–4%, NAF: 0–23%) compared to GW, depending on the heterogeneity level and NP concentration. The benefits of NAF compared to SF and GW were due to a significant decrease in gas mobility and saturation in the topmost layers, which facilitated the piston-wise movement of the front, resulting in higher sweep efficiency and recovery factor.