测试制度对凝析气藏产能评价结果的影响

Influence of testing system on productivity evaluation results of condensate gas reservoirs

凝析气藏流体性质特殊,不同测试制度下的产能测试结果差异明显。以某凝析气井产能测试资料为例,采用拟单相流法评价不同测试制度下气井无阻流量,分析无阻流量差异产生的原因。结果表明当井底流压低于流体的露点压力时,随着测试油嘴尺寸增加,近井地带凝析油析出范围增加,气体流动阻力增加,导致气井解释的无阻流量明显下降;凝析油在近井地带析出产生的表皮系数贡献较大,远井地带析出对表皮系数影响较小。该评价结果对凝析气井产能评价具有一定指导意义。

For condensate gas reservoirs with special fluid properties,the productivity test results under different systems vary significantly.Taking the productivity test data of a condensate gas well as example,the pseudo-single-phase flow method was used to evaluate the absolute open flow potential(AOFP)of the condensate gas well under different testing systems,and the reasons for the difference in AOFP were analyzed.The results show that when the bottomhole flow pressure is lower than the dew point pressure of the fluid,with the increase of the test nozzle size,the condensate precipitation range in the near-wellbore area increases,and the gas flow resistance increases,resulting in a significant decrease in the interpreted AOFP of the well.In addition,the precipitation of condensate oil in near-wellbore area contributes greatly to the skin factor,and the precipitation of condensate oil in far-wellbore area has little effect on the skin factor.The evaluation results are of certain significance for the productivity evaluation of condensate gas wells.