基于COMSOL软件的半线圈电磁远探测响应特性分析  

Analysis of Response Characteristics of Half-coil Electromagnetic Remote Detection Based on COMSOL Software

作　　者：仵杰[1,2] 胡静 云腾 WU Jie;HU Jing;YUN Teng(College of Electronic Engineering,Xi’ an Shiyou University,Xi’ an,Shaanxi 710065,China;Shaanxi Key Laboratory of Measurement and Control Technology for Oil and Gas Wells,Xi’ an,Shaanxi 710065,China)

机构地区：[1]西安石油大学电子工程学院,陕西西安710065 [2]陕西省油气井测控技术重点实验室,陕西西安710065

出　　处：《西安石油大学学报（自然科学版）》2022年第2期95-101,124,共8页Journal of Xi’an Shiyou University（Natural Science Edition）

基　　金：国家“十三五”重大专项课题“测井交互精细融合处理平台”(2017ZX05019001);西安石油大学研究生创新与实践能力培养项目(YCS19113051)。

摘　　要：传统电法测井仪器探测深度仅数米,无法满足井周数十米水平井地层边界识别的需求。传统的电磁远探测方法都是基于磁场进行计算的,本文利用半线圈所具有的远探测能力,同时测量电场强度和磁场强度,计算了仪器旋转角度、工作频率、线圈系源距、仪器距边界距离等因素对半线圈响应特性的影响。研究表明:半线圈对旋转角度反应敏感;半线圈接收的信号强度随源距的增大而单调减小,源距越小,接收信号强度越强,趋肤效应影响越小;半线圈信号强度随频率的增大呈先增大后减小的趋势;频率较小时,信号强度受源距的影响较小,频率较大时,信号强度受源距的影响较大,且信号衰减严重;半线圈探边能力优于全线圈,且半线圈衰减缓慢,半线圈工作频率为1 kHz时,源距对信号强度几乎没有影响,半线圈的探边距离均可达到30 m。通过计算分析半线圈在不同情况下的探测特性,设计最远探测深度可达30 m的仪器工作频率、源距,进一步分析仪器响应特性,为实际仪器设计和应用分析提供理论依据。The detection depth of traditional electrical logging tools is only a few meters,which cannot meet the needs of stratum boundary identification of horizontal wells in tens of meters around the well.The calculation of traditional electromagnetic remote detection methods is based on magnetic fields.In this paper,the electric field strength and the magnetic field strength are measured at the same time by means of remote detection ability of half-coil,and the influences of instrument rotation angle,working frequency,coil source distance and the distance from instrument to boundary on the response characteristics of the half coil are calculated.It is shown that the half-coil is sensitive to the instrumentrotation angle.The signal strength received by the half-coil decreases monotonically with the increase of the coil source distance.The smaller the coil source distance,the stronger the received signal strength and the smaller the skin effect.The signal strength of the half-coil first increases and then decreases with the increase of working frequency.When the frequency is small,the signal strength is less affected by the coil source distance;when the frequency is high,the signal strength is greatly affected by the coil source distance,and the signal attenuation is serious.The stratum boundary detection ability of the half-coil is better than that of the full coil,and the signal attenuation of half-coil is slower.When the working frequency of the half-coil is 1kHz,the coil source distance has almost no effect on the signal strength,and the boundary detection distance of the half-coil can reach 30m.Through calculation and analysis of the detection characteristics of the half-coil under different conditions,the working frequency and coil source distance of the instrument with a maximum detection depth of 30 meters are designed,and the response characteristics of the instrument are further analyzed to provide a theoretical basis for actual design and application of instrument.

关 键 词：COMSOL软件 半线圈 远探测 电法测井 

分 类 号：P631.8[天文地球—地质矿产勘探]