浅层气井产能资料异常原因分析及修正方法

Cause Analysis and Modification Method of Abnormality of Gas Well Deliverability Test Data in Shallow Reservoir

浅层气井由于井筒积液排除和表皮系数变化,造成稳定产能资料异常、二项式产能直线方程出现反向的情况,致使不能得到气井稳定产能方程,更得不到气井无阻流量。为了使测试资料得到有效利用,根据稳定产能评价理论和试井基础知识,通过考虑表皮系数的变化,折算各工作制度下附加压降,对各工作制度流压进行表皮效应附加压降修正,得到正常的二项式直线方程,得到气井产能方程和无阻流量。采用不稳定IPR产能评价方法,对修正后得到的无阻流量进行验证,表明该修正方法合理可靠。

Due to flowing out of wellbore loaded fluid and changing of skin factor in gas wells in shallow reservoir,deliverability test data become abnormal,and laminar-inertial-turbulent deliverability equation also becomes abnormal,and so no correct AOFP can be obtained.In order to make test data to be useful,additional pressure drops caused by changing skin factor under different chokes are calculated by using theory of steady deliverability evaluation and well test;then modify the pressure differences corresponding to every chokes with the calculated additional pressure drops,and obtain normal laminar-inertial-turbulent deliverability equation and AOFP.Verified by transient IPR deliverability evaluation showed that the method is reasonable and reliable.