Experimental Study on Depletion Development Mechanism in Low Permeability Gas Reservoir

In order to study the development characteristics of low permeability gas reservoirs, long cores sampled from natural outcrop are selected to carry out depletion development experiments by using two development modes, namely constant production and constant pressure development modes. The results show: when the average flow rate is equal to bottomhole pressure,constant production development mode is adopted, reservoir pressure drops evenly and gas produces stably. Therefore, its requirements for gas production equipment are relatively low, although its recovery percent is 2% lower than that when constant pressure development mode is adopted. Moreover, when constant production development mode is adopted, the higher the flow rate, the shorter the stable production period and lower the recovery percent. The fitted experimental data shows that the gas well may get reasonable production which is stability and high efficiency when produced in 20%~30% of AFO.