测井技术2025，Vol.49Issue(6)：868-878,916,12.DOI:10.16489/j.issn.1004-1338.2025.06.005
随钻电磁波超前探测方法与界面敏感性分析
Analysis of Look-Ahead Electromagnetic Logging While Drilling Method and Bed Boundary Detection Sensitivity
摘要
Abstract
Look-ahead electromagnetic(EM)logging while drilling(LWD)enables the prediction of formation boundaries ahead of the bit,providing critical support for the"geostopping"decision.This technique is vital for enhancing the safety and efficiency of drilling in deep and ultra-deep wells.To quantitatively evaluate the performance of look-ahead EM LWD,this study developed forward modeling frameworks for multi-boundary formations,defined a sensitivity function to characterize the signal's response intensity to boundaries,and proposed a boundary sensitivity analysis method.A systematic investigation was conducted on the sensitivity patterns under varying tool parameters,formation parameters,and interlayer properties.The research results show that:① Both the amplitude ratio signal value AR and phase difference signal values PR of the look-ahead EM LWD decay as the tool approaches a low-resistivity boundary,while their sensitivity to the boundary enhances significantly.The PR provides greater detection depth and smaller blind zone compared to phase difference.② Increasing spacing or reducing operating frequency extends the detection range,though frequency reduction attenuates boundary sensitivity.Under specific high-frequency conditions,long-spacing tools exhibit superior forward detection capability in AR.③ The tool shows high sensitivity to adjacent low-resistivity layers with extended detection range,while demonstrating poor response to layers with similar resistivity,accompanied by detectable blind zones.④ The presence of interlayers alters detection responses:thick low-resistivity interbeds enhance detection distance with notable sensitivity differences at upper and lower boundaries,whereas high-resistivity interlayers shield the signal and diminish detection capability.This study confirms that the quantitative methodology based on multi-boundary modeling and sensitivity analysis effectively characterizes look-ahead response patterns,providing critical insights for blind zone identification,parameter optimization,and accurate boundary detection in look-ahead EM LWD applications.关键词
随钻电磁波/超前探测距离/敏感性/夹层影响/地层界面/低电阻率地层/定量评价/参数优化Key words
electromagnetic logging while drilling/depth of detection of look-ahead measurement/sensitivity/interlayer effect/formation boundary/low-resistivity formation/quantitative evaluation/parameter optimization分类
天文与地球科学引用本文复制引用
ZENG Yunxin,WU Zhenguan,AI Weiping,YUE Xizhou,LIAO Xiaoqiao..随钻电磁波超前探测方法与界面敏感性分析[J].测井技术,2025,49(6):868-878,916,12.基金项目
国家自然科学基金青年基金项目"超深储层随钻电磁波聚焦前视探测与成像方法研究"(42304140) （42304140）
四川省自然科学基金项目"随钻电磁波测井超远探测方法与地质导向应用基础研究"(2023NSFSC0771) （2023NSFSC0771）
中国石油科技创新基金项目"远探测随钻电磁波测井多维-跨维模拟方法研究"(2021DQ02-0401) （2021DQ02-0401）
中国博士后科学基金项目"参数-像素混合驱动的远探测随钻电磁波测井反演方法研究"(2022MD713806) （2022MD713806）
中国海洋石油集团有限公司测井与定向钻井重点实验室开放基金项目"随钻电磁波前向增强探测理论基础与关键技术研究"(KJQZ-2024-1103) （KJQZ-2024-1103）
