Novel chemical flood combination of CSA particles and strong emulsifying surfactant in heterogeneous reservoirs

In-depth profile control agents and surfactant have been successfully applied to control excess water production and extend the lifetime of oilfields. In this study, a novel chemical flood combination composed of controllable self-aggregating particles (CSA), and a surfactant with strong emulsifying capability was designed for heterogeneous reservoirs. A series of physical experiments were performed to investigate the injection ability, plugging performance and plugging mechanisms of CSA particles. Besides, the dominating behavior of surfactant and the effect of heterogeneity degree variation were conducted in a 2D heterogeneous model and artificial cores. More importantly, the synergistic effect of chemical flood combination and adaptability on heterogeneity were explored. The results show, the emulsifying capability of surfactant plays a key role to the oil recovery, and its enhanced oil recovery (EOR) performance is controlled by the heterogeneity degree variation. Meanwhile, CSA particles exhibit an outstanding injection ability for in-depth penetration, and a promising plugging performance with an effective flow-resistant distribution because of its physical and chemical action. Moreover, the synergism of chemical flood combination, CSA particles improving in-depth swept volume and a highly efficient surfactant, contributes to EOR potentials and adaptability on heterogeneity degree variation. Therefore, the findings of this study would provide a novel method for EOR in heterogeneous reservoirs, which can be a candidate with great potentials for field application.