Dynamic productivity prediction model for fracturing wells in low permeability gas reservoir

Based on thesteady seepage theory, according to the change characteristics of gas seepage rule after fracturing, considering the gas PVT parameters change with formation pressure, and combining with material balance equation, this paper derived and established a dynamic productivity prediction model for infinite conductivity vertically fractured wells in low permeability reservoir with non-linear seepage, and analyzed the effect of non-linear seepage characteristics and production on gas well productivity. The result shows that the greater the start-up pressure gradient and deformation coefficient of permeability are, the more the stable production period decreases, and the longer the production life is, the slower the formation pressure decline. The larger the slippage factor is, the more the stable production period increases, and the shorter the production life is, the faster the formation pressure decline. The greater the gas production rate is, the more the stable production period decreases, and the shorter the production life is, the faster the formation pressure decline. The bottom hole pressure has less effect on the variation law of the gas well productivity.