EFDT地层测试泵抽取样过程数值模拟分析  

Numerical simulation analysis of fluid sampling process during EFDT formation testing

作　　者：于恩毅 邸元[1] 吴大卫 YU Enyi;DI Yuan;WU Dawei(College of Engineering,Peking University,Beijing 100871,China;Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 100083,China)

机构地区：[1]北京大学工学院,北京100871 [2]中国石油化工股份有限公司石油勘探开发研究院,北京100083

出　　处：《东北石油大学学报》2023年第6期79-88,I0006,共11页Journal of Northeast Petroleum University

基　　金：国家自然科学基金项目(51674010)。

摘　　要：为提高电缆地层测试工具EFDT泵抽取样的效率,对钻井液滤液和原始地层流体分别建立质量守恒方程,采用有限体积法进行空间离散,应用全隐式格式和Newton-Raphson迭代法求解方程,建立泵抽取样过程数学模型,编制地层流体泵抽取样数值模拟程序。对不同类型探针(标准探针、大极板式探针和三维径向探针)的泵抽取样过程进行数值模拟分析。结果表明:三维径向探针可以显著增加过流面积,极大缩短抽取合格样品时间,在低渗和中高渗地层中能保持较高的作业效率,适合复杂地层采样作业。在泵抽取样过程中,标准探针和大极板式探针钻井液滤液和原始地层流体的流动呈“锥”状的两相驱替流态,原始地层流体突破较早,清理钻井液滤液、达到取样标准的时间较长。该结果为电缆地层测试地层流体泵抽取样过程中探针的选取和泵抽时间的估计提供参考。To enhance the EFDT sampling efficiency of wireline formation testing,we developed a numerical model of the fluid sampling process.Mass conservation equations were constructed for both drilling fluid filtrate and virgin formation fluid.The finite volume approach was utilized for spatial discretization,and the solution was obtained by Newton-Raphson iterative with a fully implicit scheme.We simulated and analyzed the sampling process with different probes,namely the standard probe,elongated probe,and 3D probe.The results show that the 3D probe significantly increases the flow area and greatly shortens the sampling time of obtaining qualified samples.Besides,the 3D probe can maintain excellent operation efficiency not only in formations of intermediate to high permeability but also in low permeability formations.Hence,it proves to be more suitable for intricate formation sampling operations.The standard probe and elongated probe exhibited a conical flow pattern during fluid sampling,enabling them to withdraw the virgin formation fluid at an earlier stage,but reach the requirements comparatively more slowly.The results could serve as a valuable reference for the selection of probe and the estimation of pump-out time during wireline formation fluid sampling.

关 键 词：电缆地层测试 EFDT 地层流体取样 泵抽 数值模拟 探针 钻井液滤液 

分 类 号：TE312[石油与天然气工程—油气田开发工程] P631.84[天文地球—地质矿产勘探]