Method for improving oil recovery ratio through continuous-phase composite oil displacement

The invention provides a method for improving oil recovery ratio through continuous-phase composite oil displacement. The method includes the steps of firstly, injecting weak gel solution into an oilreservoir through a water injection well to improve the oil-water fluidity ratio of the oil reservoir, plugging a high-permeability reservoir, and enabling oil in the reservoir to flow to a productionwell to be collected; and secondly, after a cross-linked polymer is injected, surfactant solution is injected into the same water injection well to reduce oil-water interfacial tension, the oil and the water are separated, and the oil enters the production well to be collected. The method for improving the oil recovery ratio through continuous-phase composite oil displacement can increase the viscosity of the water, reduce the water-oil fluidity ratio, adjust the water absorption profile of a stratum, reduce the oil-water interfacial tension, improve the edge wettability and reduce the pressure of the water injection