基于随钻电阻率成像测井仪的洞穴评价模型理论研究  

Theoretical study on cave evaluation model based on LWD resistivity imaging tool

作　　者：康正明 柯式镇[3] 李新[4] 倪卫宁[4] 李飞[1,2] KANG Zhengming;KE Shizhen;LI Xin;NI Weining;LI Fei(Shaanxi Key Laboratory of Measurement and Control Technology for Oil and GasWells,Xi'an Shiyou University,Xi'an 710065,China;School of Electronic Engineering,Xi'an Shiyou University,Xi'an 710065,China;College of Geophysics,China University of Petroleum,Beijing 102249,China;Sinopec Research Institute of Petroleum Engineering,Beijing 100101,China)

机构地区：[1]西安石油大学陕西省油气井测控技术重点实验室,陕西西安710065 [2]西安石油大学电子工程学院,陕西西安710065 [3]中国石油大学(北京)地球物理学院,北京102249 [4]中国石化石油工程技术研究院,北京100101

出　　处：《中南大学学报（自然科学版）》2021年第5期1542-1551,共10页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(U19B6003,U20B2029);陕西省教育厅科学研究计划项目(20JS125);陕西省重点研发计划项目(2021KW-33);陕西省自然科学基础研究计划项目(2021JQ-590)。

摘　　要：基于3D有限元素法,对柱状过井眼型洞穴地层的随钻电阻率成像测井响应进行数值模拟;设计单洞穴和多洞穴2种地层模型,考察洞穴直径、洞穴电阻率、洞穴延伸长度对测量信号的影响。为了更加直观地反映不同因素对洞穴的影响,对仪器在多洞穴地层中成像采样过程进行模拟。基于正演结果,利用最大电流对比度概念建立洞穴直径、洞穴延伸长度理论计算模型。研究结果表明,考虑井眼影响时,洞穴直径与测量信号之间呈现出非单调关系;忽略井眼或贴井壁测量时,洞穴直径与测量信号呈现线性关系,大洞穴延伸长度与测量信号具有较好的幂指数关系;在不同洞穴直径下,洞穴与地层电阻率对比度与测量信号呈幂指数关系。The numerical simulation of the response of logging while drilling(LWD)resistivity imaging was realized based on the 3D finite element method.The single-cave and multi-cave formation models were designed respectively,and the influence of cave diameter,cave resistivity and cave extension on the measurement signal was investigated.Furthermore,the imaging sampling process of the tool in the multi-caved formation was simulated to reflect the influence of different factors on the cave.The theoretical calculation models of cave diameter and cave extension were established by using the concept of maximum current contrast.The results show that there is a non-monotonic relationship between the diameter of the cave and the measured signal under the influence of borehole.When the tool is close to the borehole wall,there is a linear relationship between the cave diameter and the measured signal,and there is a better power index relationship between the middle cave extension and the measured signal.At different cave diameters,the resistivity contrast between cave and formation shows a power exponential relationship with the measured signal.

关 键 词：随钻测井 电阻率成像 洞穴 最大电流对比度 评价模型 

分 类 号：P319.3[天文地球—固体地球物理学]