含水低渗气藏低速非达西渗流数学模型及产能方程研究

Low-velocity Non-Darcy Gas Seepage Model and Productivity Equations of Low-permeability Water-bearing Gas Reservoirs

在低速非达西渗流实验研究基础上,对含水低渗气藏气体流动特性进行了分析,并建立了含可动水、不动水和束缚水影响下的3类低速非达西渗流数学模型,推导出了气体滑脱效应和启动压力梯度分别存在和同时存在条件下的系列气井产能公式。通过实例计算证明数学模型符合现场实际,气井产能公式可为确定不同含水条件下低渗气藏气井合理的产能提供必要的理论依据。

The flow behaviour of fluids in water-bearing gas reservoirs was analyzed based on the experimental study of low-velocity non Darcy percolation. Three kinds of mathematical models were established under the influ ences of movable water, inmovable water and combined water. Deliverability equations of gas well were obtained with the gas slippage effect and the threshold pressure gradient existed respectively and simultaneously. The case study proved that the study was applicable and the corresponding equations could provide a necessary theoretical basis for defining reasonable gas-well deliverability under different water conditions.