The invention discloses an experimental test method of competitive
dissolution of CO<2> in an oil-water mixture
system. The experimental test method of competitive
dissolution of CO<2> in the oil-water mixture
system comprises the steps of: configuring a
crude oil sample and a
formation water sample, wherein injected gas is industrial CO<2> gas; injecting the
formation water sample, an oil sampleand the CO<2> gas in a
sample preparation device; discharging the oil sample, recording the volume of
crude oil discharged from a separator and the volume of CO<2> in a gasometer, and calculating thegas-oil ratio after CO<2> is dissolved by the
crude oil; recording the volume of
formation water discharged from the separator and the volume of CO<2> in the gasometer, and calculating the gas-water ratio after CO<2> is dissolved in water phase; and, gradually increasing
displacement pressure, repeating the step, so that the volume of dissolved CO<2> in the crude oil and the formation water samplein series of pressure conditions is obtained, and furthermore, calculating the dissolved CO<2> gas-water ratio GWR in the water phase and the dissolved CO<2> gas-oil ratio GOR in the oil phasein each pressure condition. The experimental test method disclosed by the invention is reliable in principle, simple and applicative, can precisely evaluate and compare the dissolving condition when CO<2> is contacted with the crude oil and the formation water at the same time in a true reservoir condition, and has wide market application prospect.