随钻双感应测井仪背景影响研究  

The Background Influence Research of LWD Dual-induction Logging Instrument

作　　者：仵杰[1] 叶雨[1] 白茹宝 牒勇 

机构地区：[1]西安石油大学光电油气测井与检测教育部重点实验室,陕西西安710065 [2]中国石油集团测井有限公司随钻测井中心,陕西西安710054

出　　处：《石油管材与仪器》2015年第3期46-50,58,共6页Petroleum Tubular Goods & Instruments

摘　　要：分析随钻双感应测井仪背景影响对仪器研制具有重要的实际意义。本文通过COMSOL有限元软件数值计算分析背景参数(金属钻铤、反射层和磁芯)在不同地层电导率下对随钻双感应测井响应特性的影响,揭示了响应机理。当钻铤电导率大于107S/m时,钻铤对深感应响应的影响很小,对浅感应的影响不能忽略。钻铤长度变化对仪器的响应影响可以忽略。视电导率与钻铤半径近似线性关系。在地层电导率小于1S/m时,钻铤对深、浅感应的响应影响不大。反射层改变了钻铤对基值的非线性影响,随地层电导率增加,深感应的基值影响非线性减小,浅感应的非线性增加。深、浅感应的响应随着磁芯相对磁导率的增加非线性增加,相对磁导率在100至200之间时,对信号增强最明显。深、浅感应在磁芯实心与磁芯空心作用下的响应的比值约为固定值1.2。There is important practical significance of analysing the background influence of LWD dual - induction logging tool. In this arti- cle, the influences on the response feature of LWD dual - induction logging is computed and analyzed using COMSOL software when the for- mation conductivity is changed. The effect mechanism of mental drill callar and high permeability magnetic core on the dual - induction logging while drilling are revealed. The effect of drill collar conductivity on the deep induction is a little when the conductivity is greater than 107 S/m, shallow induction can＇t be ignored. The influence of drill collar length on the response can be neglected and the apparent conductivity is approximately proportional to the drill collar radius. The effect of drill collar on the deep and shallow induction is a little when the formation conductivity is less than lS/m. reflector has changed the nonlinear influence of drill collar on the base value. The influence of the deep induction has a nonlinear decrease with the increase of the formation conductivity. But the shallow induction increases. The responses of the deep and shallow induction have a nonlinear increase with the increase of the relative magnetic core permeability. The signal intensity is boosted obviously when the relative magnetic core permeability is between 100 and 200. Tile ratio of response of the deep and shallow in- duction under the action of solid magnet core and hollow magnet core approximates a fixed value （1.2）.

关 键 词：随钻双感应测井 金属钻铤 反射层 磁芯 COMSOL有限元软件 

分 类 号：P631.43[天文地球—地质矿产勘探]