The invention belongs to the field of oil-gas
field development and relates to an experimental evaluation method for
fracturing fluid damage in an unconventional tight sandstone oil-gas exploration and development process. The method includes: subjecting
fracturing fluid to high-pressure instant reverse injection into a
rock core, and simulating flow invasion damages of
fracturing fluid in cracks in a continuous extension process after a stratum is fractured by the fracturing fluid; adopting a high-speed
centrifuge to set up original
water saturation of a reservoir; under the condition of the original
water saturation of the reservoir, adopting
nitrogen for testing permeability before and after injection of the fracturing fluid into the
rock core, and judging fracturing fluid damage degrees according to gas log permeability change rate. By complete
simulation of a fracturing
fluid injection mode in a fracturing process, adoption of
nitrogen for testing permeability accords with seepage characteristics of the tight sandstone gas reservoir, and defects of high experimental
displacement pressure, long displacement time, large experimental data errors and the like are avoided.