Study of the multiple-profile control system to enhance oil recovery after polymer flooding

There is still half oil remaining in the reservoir after polymer flooding. This paper has carried out the laboratory studies on multi-profile control and displacement system to enhance oil recovery after polymer flooding. First of all, the multiple system comprising a gel particle, cross-linking agent and high effective surfactant, is screened according to specific criteria. Then the profile control experiments on binary and ternary system after polymer flooding are separately carried out to verify the potential of enhanced oil recovery. The results show that the multiple injection system not only blocks the high permeable layers and channels, but also makes full use of medium and low permeability layers, finally improving the whole sweep efficiency. Owing to the surfactant injection, the displacement efficiency is simultaneously improved to some extent, and thus greatly improves the oil recovery after polymer flooding.