Study on Fluids Flow Characteristics of Water-Gas Mutual Flooding in Sandstone Underground Gas Storage with Edge Water

It is distinguished from that of a routine gas field that the physics simulation study on multiphase flow characteristics of watergas mutual flooding in sandstone Underground Gas Storage with edge water. The former mainly solves multiphase flow characteristics of water-gas mutual flooding by the alternating displacement of fluids and much higher flow rates. So it has its particularity and complexity in the design of the experimental system and the process. By independent designing physical simulation experiment system and process on water-gas mutual flooding, the paper mainly solved evaluation technique of multiphase flow characteristics on multi-cycle water-gas mutual Flooding, and established evaluation methods of pore volume utilization on multi-cycle water-gas mutual flooding. All of these provide a better idea to evaluate fluids flow mechanism of water-gas mutual flooding in Underground Gas Storage with Edge Water. Gas-water relative permeability through cores with three different permeability levels was investigated by physical simulation experiments of multiple water-gas mutual flooding. The results of the study show that, with the increase in the number of water-gas mutual flooding, gas relative permeability reduced in the same water saturation. Meanwhile gas-water two phase flowing regions became narrow, and both of the gas flowing capacity and pore volume utilization were reduced. After three times water-gas mutual flooding, pore volume utilization was about 45.9~70.0%.