复合油藏产量计算方法分析及内区污染规模判别  

Analysis of production calculation methods for composite reservoirs and discrimination of pollution scale in inner zone

作　　者：刘全刚 郭小哲[2] 王晓超 韩立杰 崔国亮 LIU Quangang;GUO Xiaozhe;WANG Xiaochao;HAN Lijie;CUI Guoliang(CNOOC EnerTech-Drilling&Production Co.,Tianjin 300452,China;College of Petroleum Engineering,China University of Petroleum(Beijing),Beijing 102249,China)

机构地区：[1]中海油能源发展股份有限公司工程技术分公司,天津300452 [2]中国石油大学(北京)石油工程学院,北京102249

出　　处：《油气井测试》2022年第2期7-12,共6页Well Testing

基　　金：中海油能源发展工程技术公司项目“疏松砂岩储层压裂特征研究”(ZX2021ZCGCF5997)。

摘　　要：井筒作业或储层长期驱替导致近井范围渗透率降低,形成内区与外区复合油藏。为明确内区规模对产液量的影响,分析对比了渗流阻力法、附加阻力法和调和平均法3种产量计算方法。结果表明3种不同的产量计算方法仅存在很小的误差;对产量的影响中,当污染程度较大时即使较小的内区半径也会产生大幅的产量降低;不同的原始储层渗透率和原油黏度,由内区规模的不同导致的产量下降幅度基本一致。在污染规模判别中,基于“外污染”和“内污染”特征,提出了以产量下降50%为界线的7个污染规模判别标准,为分析油井产量大幅降低的原因提供了技术支持。Wellbore operation or long-term reservoir displacement reduces the permeability of strata near the wellbore,forming a composite reservoir with inner and outer zones.To clarify the influence of inner zone size on liquid production,three production calculation methods,i.e.seepage resistance method,additional resistance method and harmonic mean method,were analyzed and compared in this paper.The results show that the three production calculation methods have only small errors.When the pollution scale is large,even a small inner zone radius may lead to a significant decline of production.Under different conditions of original reservoir permeability and crude oil viscosity,the production declines caused by different inner zone sizes are basically the same.For the discrimination of pollution scale,based on the features of“outer pollution”and“inner pollution”,seven discrimination criteria of pollution scale with the production decline of 50%as the boundary were proposed,which provides technical support for analyzing the reasons for sharp decline of well production.

关 键 词：复合油藏 储层污染 外污染 内污染 产量计算 非均质油藏 判别标准 油层保护 

分 类 号：TE328[石油与天然气工程—油气田开发工程]