低渗透水平气井产能分析三项式的推导和应用  

Derivation and Application of Trinomial in Low Permeability Horizontal Gas Well Productivity Analysis

作　　者：王永胜[1] 梅海燕[1] 张茂林[1] 杨乾龙[1] 龙芳[1] 

机构地区：[1]西南石油大学石油与天然气工程学院,四川成都610500

出　　处：《天然气与石油》2014年第6期53-57,11-12,共5页Natural Gas and Oil

基　　金：国家科技重大专项资助项目(2011 ZX 05024)

摘　　要：低渗透气藏由于应力敏感与启动压力梯度影响,采用常规二项式产能方程已难以描述其真实的渗流特征。从渗流力学理论出发,基于保角变换和等值渗流阻力原理建立了考虑应力敏感、启动压力梯度和高速非达西效应的水平气井三项式产能方程,并对考虑应力敏感的拟压力进行了新设定,给出了低压、较高压力以及中间压力状态下的拟压力计算方法,导出了无阻流量计算公式。分析了应力敏感与启动压力校正系数C和不同应力敏感系数对无阻流量的影响。水平气井三项式产能方程解决了使用常规二项式产能方程分析气井产能中当斜率为负时不能分析此气井产能的问题。It is difficult to describe actual seepage characteristics of low permeability gas reservoir by using conventional binomial productivity equation due to effects of stress sensitivity and start-up pressure gradient.Starting from seepage flow mechanics theory and based on the principle of conformal transformation and equivalent percolating resistance,established is trinomial productivity equation for horizontal gas well with consideration of stress sensitivity,start-up pressure gradient and high velocity non-Darcy effect,conducted is new definition of pseudo pressure considering stress sensibility,developed is a method for calculating pseudo pressure under low,intermediate and high pressure conditions and derived is a calculation formula for absolute open flow rate.Analyzed is effect of correction coefficient C for stress sensibility and start-up pressure gradient and different stress sensibility coefficients on absolute open flow rate.Productivity of horizontal gas well can not be analyzed by using conventional binomial productivity equation when it has negative slope and the trinomial productivity equation can solve the problem.

关 键 词：水平气井 应力敏感 启动压力梯度 高速非达西效应 三项式产能方程 

分 类 号：TE328[石油与天然气工程—油气田开发工程]