Full-Text Search:
Home|Journal Papers|About CNKI|User Service|FAQ|Contact Us|中文
《Chinese Journal of Geophysics》 2009-07
Add to Favorite Get Latest Update

Improvement for interpretation of central loop transient electromagnetic method

SHI Xian-Xin~(1,2),YAN Shu~3,FU Jun-Mei~2,CHEN Ming-Sheng~11 Xi'an Branch,China Coal Research Institute,Xi'an 710054,China2 School of Electronic and Information Engineering,Xi'an Jiaotong University,Xi'an 710049,China3 School of Computer Science and Telecommunication Engineering,Jiangsu University,Zhenjiang 212013,China  
The apparent resistivity of the transient electromagnetic central loop configuration is usually derived from the field expressions of the center of the loop source.But in practical explorations,the measurement is taken out in one—third of the area of the center of the transmitter loop in order to raise the efficiency.The analysis on field distribution characteristics shows that the difference between induced electromotive force at the central point and at the edge of the measuring area is up to 15%~25%,which can not be ignored as compared with anomalies caused by collapse columns and conducting small faults buried at the depth of 600~1000 m widely existing in the north China type coal measures stratum.The equation of the large rectangular loop source cloud expresses induced electromotive force at any field points accurately, the apparent resistivity derived from that is not subject to edge effects;the observation is still made with central loop pattern and in near zone,and the simple and direct relationship between induced electromotive force and apparent resistivity could be maintained.These measures have further improved prospecting precision of transient electromagnetic method of central loop.In the case of existing conductive overburden layer,the anomalous sign of the collapsed column buried at 500~700 m depth is evident,which has been verified by mining.
【Fund】: 国家重点基础研究发展计划(973)项目(2006CB202207);; 国家自然科学基金项目(40374052);; 江苏大学高级人才启动基金项目(05JDG054);; 煤炭科学研究总院西安研究院技术创新基金项目(2006XAYCX014)资助.
【CateGory Index】: P631.325
Download(CAJ format) Download(PDF format)
CAJViewer7.0 supports all the CNKI file formats; AdobeReader only supports the PDF format.
©2006 Tsinghua Tongfang Knowledge Network Technology Co., Ltd.(Beijing)(TTKN) All rights reserved