考虑多因素的低渗气藏产能方程

低渗气藏由于其具有孔喉小、物性差、渗透率低等特征,在实际开发中难度较大,对于技术要求较高。为了更加准确计算低渗透气藏的气井产能,对低渗气藏渗流特征进行了描述和数学表征,特别是针对前人推导产能方程考虑因素不全和不准确的现象进行了补充和修正,基于拟启动压力梯度模型,推导和建立了同时考虑滑脱效应、启动压力梯度、应力敏感、高速非达西和水锁损害的低渗气藏产能方程,并对影响因素进行了敏感性分析。结果表明,滑脱效应使气井产能变大,启动压力梯度、应力敏感和水锁损害使气井产能变小；水锁损害对气井产能影响最大,启动压力梯度次之,应力敏感和滑脱效应分列三四；通过实际气藏数据和生产资料验证,产能方程对于现场开发具有指导意义。

Productivity Equation of Low Permeability Gas Reservoir considering Multiple Factors

Low permeability gas reservoir has the characteristics of small pore throat, poor physical property and low permeability. In order to more accurately calculate the gas well production capacity of low permeability gas reservoir, the seepage characteristics of low permeability gas reservoir are described and the mathematical representation, especially for previous productivity equation is derived factor is not complete and not accurate phenomenon is the supplement and correction, based on the proposed start-up pressure gradient model, is derived and established at the same time considering slippage effect and threshold pressure gradient and stress sensitivity, high-speed non-darcy and water locking damage of low permeability gas reservoir productivity equation, and the factors affecting the sensitivity analysis. The results show that the slippage effect increases the productivity of gas Wells, and the pressure gradient, stress sensitivity and water lock damage decrease the productivity of gas Wells. Water lock damage has the largest effect on gas well productivity, followed by starting pressure gradient, stress sensitivity and slippage effect. Through the verification of actual gas reservoir data and production data, the productivity equation has guiding significance for field development.