致密气藏压胀松动井产能预测模型

PRODUCTIVITY PREDICTING MODEL OF THE DILATANT LOOSENED WELL IN THE TIGHT GAS RESERVOIR

针对致密气藏气井压胀松动增产后产生压胀松动区,基于稳定流理论,建立了考虑滑脱效应、启动压力梯度、应力敏感共同影响下致密气藏压胀松动气井产能预测模型,通过实例分析了各因素对气井产能的影响。研究结果表明:气井产能随启动压力梯度和渗透率变形系数增大而下降,其中n值变化对气井产能影响小,m值越小气井产能下降越大,而随滑脱因子增大而增加;在高流压阶段,压胀半径对气井产能影响程度较小,随着井底压力的降低,压胀半径对气井产能影响程度增强。

In view of the loosened area resulted from the dilatant loosening simulation for the gas well in tight gas reservoirs, on the basis of the steady seepage theory, considering the mutual influence among the slippage effect, start-up pressure gradient and stress sensitivity the reservoirs, the well predicting model was established after the simulation, and moreover with the help of the case history analysis, the influencing factors of the gas well productiv- ity were figured out. The achievements show that the gas well productivity declines with the rises of the start-up pressure gradient and permeability deformation coefficient, in detail, Value n has a little influence on the produc- tivity, the less Value m is, the more the productivity will decrease, but along with the slippage factor enlargement, the productivity continues to increase; in the stage of the high flowing pressure, the radius of the dilatancy has small effect on the gas well productivity, while with the drop of the bottom-hole pressure, the corresponding effect enhances to a certain degree.