低界面张力下乳化性能对二元复合体系驱油效率的影响OA

Emulsification capability and emulsion stability significantly influence the oil displacement of binary composite systems by in-situ emulsification.However,their related mechanisms are currently not systematically understood.To address this issue,binary composite systems with significant differences in the characterization parameter of emulsification capability,namely emulsification index(EI)and that of emulsion stability,namely the emulsion stability index(SI)were selected,and microfluidic displacement experiments were conducted to clarify the influence of emulsification performance on oil displacement efficiency of these systems.The experimental results indicate that binary composite systems with strong emulsification capability(EI value of 1.459,1.462,and 1.398),regardless of the magnitude of their emulsion stability index,achieve an oil displacement efficiency increase of over 28.0%.In contrast,the binary composite system with a weak emulsification capability(EI value of 0.463)records an oil displacement efficiency increase of less than 20.0%.Both excessively high and low SI are detrimental to the oil displacement efficiency increase of binary composite systems.The binary composite system exhibiting a moderate SI coupled with strong emulsification capability yields the highest oil displacement efficiency increase of 42.4%.Clustered residual oil is the primary type of residual oil after water flooding,and its mobilization degree shows a positive correlation with the increase in oil displacement efficiency.The results indicate that for water-flooded reservoirs,the emulsification performance parameters required for binary composite systems by in-situ emulsification are strong emulsification capability and moderate emulsion stability.