Abstract: The fluid flow in oil reservoir-type gas storage involve three phases of oil, gas, and water. The storage capacity space is not only the pore space for gas displacement of liquid, but oil and gas also have dissolution and component mass transfer effects. Based on operational state of oil reservoir type storage, the paper carried on relative permeability experiments of multi-cycle gas-water、oil-water and gas-oil mutual driving, and physical simulation of multi-cycle injection and production in long cores, analysed the seepage laws of two phase mutual driving and gas driving fluid efficiencies and fluid saturation changes of multi-cycle injection and production, studied the influences of multi-cycle injection and production to seepage capacity、sweep efficiency and storage space. The experimental result showed: (1) In the multi-stage two-way coupled process, the aqueous phase reduces the permeability of the gas phase and oil phase, which is not conducive to the establishment and expansion of gas storage facilities. The gas-oil two-way coupled process reduces the residual oil saturation and increases the space of mobile fluid, which is conducive to the establishment and expansion of gas storage facilities. (2) Carrying out physical simulation of building storaget with gas driving pil to limitation + cyclic injection-production between upper and floor pressure, the model's final oil efficiency is 65.11%, and water driving is 20%, gas driving is 37.15%, cyclic injection-production is 7.6%, gas driving is main enhanced stage, cyclic injection-production is the stage of building gas storage. (3) The pore volume of the long core gas drive liquid displacement is the main part of the storage capacity, accounting for more than 70%, the proportions of residual oil dissolved gas and residual oil shrinkage pore volume are less than 30%. The capacity stabilized after the 14th round of gas production and injection. The storage capacity and working gas volume of the gas storage are mainly affected by the gas saturation . It suggested that when building oil reservoir gas storage, it is not advisable to rush to deplete gas production, but to preferentially "lifting production", then "building gas storage", recommended to drive oil by gas with maintaining the reservoir pressure, to build gas storage by circulating injection and production when it reached the ultimate recovery efficiency, it can adequately increase oil and water recovery degree, which is conducive to increasing the storage capacity and working gas volume.

Key words: oil reservoir type gas storage, multiple cycles of mutual displacement, seepage characteristics, long core physical simulation, storage capacity, working volume