Physical simulation method for flowback after pressing of tight oil reservoir

The invention discloses a physical simulation method for flowback after pressing of a tight oil reservoir. The physical simulation method comprises the following steps: dividing an oil-water two-phase seepage region formed in a well soaking process after pressing of the tight oil reservoir into a filtration region and an imbibition region; on the basis, a filtration core and an imbibition core are respectively constructed; and then connecting the two rock cores in series, carrying out an oil-displacing-water experiment, and simulating a flowback process after pressure. By means of a nuclear magnetic resonance on-line monitoring technology, quantitative characterization of oil-water distribution characteristics in pores of the imbibition rock core and the filtration rock core is achieved. According to the method, the whole physical process from soaking to flowback is effectively simulated, the microcosmic oil-water distribution rule in core pores in the flowback process can be analyzed by using the experimenta