井孔瞬变电磁短偏移距远探测能力研究  

A short offset transient electromagnetic method for long-distance exploration of boreholes

作　　者：李昊锦 毛玉蓉[1,2] 周磊[1,2] 谢兴兵[1,2] 郭庆明[3] 刘灿 柯相彬 贺煜斐 LI Hao-Jin;MAO Yu-Rong;ZHOU Lei;XIE Xing-Bing;GUO Qin-Ming;LIU Can;KE Xiang-Bin;HE Yi-Fei(School of Geophysics and Petroleum Resources,Yangtze University,Wuhan430100,China;Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education,Yangtze University,Wuhan430100,China;Research Institute of Logging Technology,CNPC Logging Co.Ltd.,Xi'an730077,China)

机构地区：[1]长江大学地球物理与石油资源学院,湖北武汉430100 [2]油气资源与勘探技术教育部重点实验室(长江大学),湖北武汉430100 [3]中国石油集团测井有限公司测井技术研究院,陕西西安730077

出　　处：《物探与化探》2023年第6期1563-1572,共10页Geophysical and Geochemical Exploration

基　　金：国家自然科学基金项目(42274103);中国石油化工股份有限公司科技部项目(P22163);大学生创新创业项目“井中大功率激发极化法阵列观测系统研制”。

摘　　要：在油气及矿藏资源勘探中,井孔瞬变电磁远探测技术相比于常规测井和地震方法,具有分辨率高、多参数获取、无侵入性等优势,但在实际应用中仍存在一些技术挑战和限制,需要综合考虑各种因素,选择合适的勘探方法和方式来获取地下资源的准确信息。为此,进行了井孔瞬变电磁装置关键参数对探测距离影响的研究,基于有限元法分别计算了不同收发矩、不同线圈参数、不同探测距离下低阻体和高阻体的响应。结果表明:在井孔瞬变电磁短偏移距远探测中,收发矩的大小对时间域电磁探测距离的影响不大,而线圈参数能明显影响井旁探测距离;在200匝2 A的发射线圈参数下,井孔瞬变电磁探测法对低阻体更为敏感,井旁探测距离可达40~50 m,对高阻体的探测距离为30 m。研究表明,采用小尺寸井孔瞬变电磁探测仪实现短偏移距井旁远探测是可行的。With an increase in the difficulty with the exploration of oil,gas,and mineral resources,conventional log and seismic meth-ods fail to accurately evaluate the geological structures and transverse reservoir distribution far from boreholes.Therefore,this study proposed a transient electromagnetic(TEM)method for long-distance exploration of boreholes.Specifically,this study investigated the influence of key parameters of TEM devices for boreholes on the exploration distance.Based on the finite element analysis,this study calculated the responses of low-and high-resistivity geobodies under different receiver-transmitter distances,coil parameters,and ex-ploration distances.The results showed that receiver-transmitter distances had little effect on the distance of electromagnetic exploration in the temporal domain.However,the results indicated that coil parameters had significant effects on the near-well detection distances.Under the transmitter coil parameters of 200 turns and 2A current,the TEM method for boreholes was more sensitive to low-resistivity geobodies,with near-well exploration distances reaching 40~50 m and 30 m for low-and high-resistivity geobodies,respectively.Therefore,it is feasible to conduct short-offset near-well long-distance exploration using TEM detectors with short transmitter coils for boreholes.

关 键 词：井孔瞬变电磁 短偏移距 远探测 井旁探测 有限元 

分 类 号：P631[天文地球—地质矿产勘探]