斜井各向异性地层随钻侧向测井响应规律及快速校正方法  

Response characteristics and correction of LWD laterolog in anisotropic formations and deviated boreholes

作　　者：李丰丰 倪小威 徐思慧 魏新路 刘迪仁[1] LI Fengfeng;NI Xiaowei;XU Sihui;WEI Xinlu;LIU Diren(Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education,Yangtze University,Wuhan 430100,China;Production Capacity Construction Division,PetroChina Tarim Oilfield Company,Korla 841000,Xinjiang,China;Liaohe Branch of CNPC Logging Corporation,Panjin 124000,Liaoning,China)

机构地区：[1]长江大学油气资源与勘探技术教育部重点实验室,武汉430100 [2]中国石油塔里木油田公司产能建设事业部,新疆库尔勒841000 [3]中国石油集团测井有限公司辽河分公司,辽宁盘锦124000

出　　处：《岩性油气藏》2023年第3期161-168,共8页Lithologic Reservoirs

基　　金：国家重点研发计划项目子课题“地下及井中地球物理勘探技术与装备”(编号:2018YFC060330502)资助。

摘　　要：采用有限元数值模拟方法与参数敏感性函数,模拟了螺绕环式随钻侧向测井仪在斜井各向异性地层中的响应特性;通过分析仪器对层厚/围岩、各向异性、井斜角的响应敏感程度,并基于正演结果分段拟合,针对不同的井斜角,提出一种井斜/各向异性快速校正的计算方法。研究结果表明:①当目的层厚度小于0.5 m时,仪器的响应受围岩影响严重;当目的层厚度为0.5~5.0 m时,仪器的响应同时受围岩和各向异性的影响;当目的层厚度大于5.0 m时,各向异性对仪器响应的影响占主导。②当井斜角小于30°时,测井响应受各向异性系数影响较小,视电阻率相差最大为2.5Ω·m;当井斜角大于30°时,仪器响应受各向异性影响严重,不能反映地层水平电阻率。③井斜/各向异性校正法在电导性地层与厚度较大的电阻性地层中具有更好的校正效果。The finite element numerical simulation method and parameter sensitivity function were used to simulate the response characteristics of toroidal coil excitation LWD laterolog instrument in anisotropic formation and deviated boreholes,the sensitivity of the instrument to the formation thickness/surrounding rock,anisotropy and well deviation angle were analyzed,and based on forward modeling results segment fitting,a calculation method for rapid correction of well deviation/anisotropy was proposed for different well deviation angles.The results show that:(1)When the thickness of the target layer is less than 0.5 m,the instrument response is seriously affected by the surrounding rocks.When the thickness is 0.5-5.0 m,the instrument response is affected by both the surrounding rock and anisotropy.When the thickness is greater than 5.0 m,the influence of anisotropy on the instrument response is dominant.(2)When the well deviation angle is less than 30°,the logging response is less affected by the anisotropy coefficient,and the maximum difference of apparent resistivity is 2.5Ω·m.When the well deviation angle is greater than 30°,the instrument response is seriously affected by anisotropy and cannot reflect the horizontal resistivity of the formation.(3)This method has better correction effects in conductive formation and resistive formation with larger thickness.

关 键 词：斜井 各向异性 随钻侧向测井 探测深度 分辨率 敏感性 有限元数值模拟 

分 类 号：TE353[石油与天然气工程—油气田开发工程] P618.13[天文地球—矿床学]