非均相粘弹体复合体系微观驱油机理研究

kind of preformed particle gel (PPG) with low elasticity and high viscosity, is dispersed in polymer solution to form a combination flooding system. The transport behavior of the PPG through a porous medium and its microscopic flooding mechanism were studied by visual microscopic flooding model. The enhanced oil recovery capacity of the dispersed viscoelastic combination flooding system was also studied by chemical flooding simulation tests. The results show that transport behaviors of the PPG through a porous medium can be summarized in five patterns: direct passing through, adsorbed onto rock surface, trapped by throat, deformable passing through, snap-off and pass through. Its microscopic flooding mechanism includes selective conformance control, in-depth diversion, mechanism of PPG viscoelastic displacement oil and par-tially polymer flooding. The simulation experiments show that the oil recovery efficiency increases to 84.47% after the dispersed viscoelastic combination flooding sys-tem was injected, that is 37.83% higher than water flooding and 17.64% higher than polymer flooding.