致密低渗透气藏有效供气半径的确定

Determination of Effective Drainage Radius of Gas Wells in Tight Reservoir with Low Permeability

为研究启动压力梯度对致密低渗气藏气井有效供气半径的影响,通过实验得出了苏里格气田苏6井区有效渗透率与启动压力梯度的关系;结合气体稳定渗流理论,推导出有效供气半径的计算公式,得到了不同渗透率和启动压力梯度及一定井底压力下有效供气半径的理论图版。实例计算表明,相同配产量下启动压力梯度对有效供气半径的影响比较明显。

Start-up pressure gradient for gas flow exits in tight reservoir with low permeability.In order to study the influence of start-up pressure gradient to the effective drainage radius of the gas wells in this kind of reservoir,by experiment,the relation between effective permeability and start-up pressure gradient in Well Su-6 area of Sulige Gas Field is obtained;by combining gas steady flow theory,formula of effective drainage radius is derived,and theoretical type curve of effective drainage radius under various different permeability,start-up pressure gradient and bottom hole pressure is built.Real case calculation shows that,under the same production rate condition,start-up pressure gradient would affect the effective drainage radius obviously.