多极源随钻动电测井波场特性实验研究  

Experimental study of multipole seismoelectric logging while drilling

作　　者：王军[1] 侯许佳 关威[1] 张超[1] 胡恒山[1] WANG Jun;HOU XuJia;GUAN Wei;ZHANG Chao;HU HengShan(Department of Astronautics and Mechanics,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]哈尔滨工业大学航天学院,哈尔滨150001

出　　处：《地球物理学报》2020年第8期3205-3217,共13页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41674121,41974136,41874129,11734017)资助.

摘　　要：探索基于孔隙介质动电效应的随钻测井新方法是当前测井勘探领域的热点研究之一.本文针对随钻测井情况下的动(声)-电转换机理,在砂岩模型井中进行了多极源(单/偶/四极源)随钻动电测井实验研究,记录了井中声波激发动电转换波场的时域波形,给出了各分波的时间-速度图,并与多极源随钻声波测井数据进行对比,结果表明:钻铤波诱导的动电转换信号在随钻动电测井全波中的相对幅度显著降低,从而可准确提取到地层声波的传播速度,实现了利用随钻动电测井方法测量地层波速的目的,验证了随钻动电测井技术可有效抑制钻铤波的思想.本文还进一步分析了钻铤波的动电耦合特性,并结合有机玻璃模型井中随钻动电测井和无井孔模型下的随钻声波测量,研究了伴随钻铤波电场信号的传播特性和衰减规律,深入探讨了随钻动电测井全波中钻铤波被削弱的原因,并给出了定量的实验数据分析,为随钻动电测井理论模拟的解释提供有效实验数据支撑.To develop the new logging while drilling(LWD)method with seismoelectric effect is one of the current focused topics in geophysical exploration.To further understand the coupling mechanism between the elastic field and electromagnetic field in LWD measurements,seismoelectric LWD measurements are conducted in a scaled sandstone borehole with multipole sources(monopole/dipole/quadrupole).The time domain waveforms of seismoelectric LWD signals are recorded by a high resolution experimental set-up in the laboratory.They are analyzed and compared with the signals measured from the acoustic LWD method.The comparison shows that the relative amplitudes of the seismoelectric signals induced by collar waves decrease significantly in the full waveforms of seismoelectric LWD,so that the formation wave velocities can be obtained accurately from the logging data.This confirms the theoretical prediction that the seismoelectric LWD can effectively restrain the influence of collar waves on formation waves.The coupling and attenuation characteristics of seismoelectric signals induced by collar waves are further studied based on the experimental data.Then a quantitative analysis on the mechanism of seismoelectric LWD technique is presented in this paper by combining the seismoelectric LWD measurements in a Lucite borehole and the acoustic LWD measurements in the water tank without borehole.This work is also helpful for data interpretation of theoretical simulations.

关 键 词：多极源 钻铤波 动电效应 随钻动电测井 

分 类 号：P631[天文地球—地质矿产勘探]