EULER DECONVOLUTION OF BOREHOLE THREE-COMPONENT MAGNETIC GRADIENT TENSOR AND ITS APPLICATION
LIU Tian-you1, GAO Wen-li2, FENG Jie2, XI Yu-fei1, OU Yang1
1. Institute of Geophysics & Geomatics, China University of Geosciences, Wuhan 430074, China;
2. Institute of Geophysical and Geochemical Exploration, CAGS, Langfang 065000, China
2006年The Leading Edge第一期详细介绍了磁力梯度张量的理论、仪器与野外试验结果,磁力梯度张量技术已成为磁力勘探新的热点之一。笔者介绍了磁力梯度张量的概念及优点;利用频率域与空间域方法把井中三分量磁测资料换算磁力梯度张量;根据联合反演原理与欧拉反褶积方法,推导了磁力梯度张量的联合反演方程,该方程通过权函数矩阵可以灵活对一个或多个分量反演,比文献[14]方法更具普遍性。理论模型结果表明,磁力梯度张量反演方法对井底异常的定位准确,对于3D模型,一口钻井的资料也能较好确定空间位置。将该方法用于湖北大冶铁矿18-2井三分量磁测资料的解释,得出磁力梯度张量的欧拉解集中在100~180 m与500~550 m两个深度,与钻探结果十分吻合。该结果证实了地质上关于铁矿体分布具两个台阶的推论,对大冶铁矿的深部找矿具有实际意义。
Since the paper published in The Leading Edge (No. 1 issue of 2006 ) described in detail the theory, equipments and outdoor test results of magnetic gradient tensor, this technology has become one of the hot topics of magnetic prospecting methods. This paper describes the concepts and advantages of the magnetic gradient tensor. Both frequency and spatial domain methods are used to transfer borehole three-component magnetic data to magnetic gradient tensor. According to the joint inversion principle and Euler deconvolution, the joint inversion equations for magnetic gradient tensor are deduced, which enable us to flexibly inverse one or more components based on a weighted function matrix, and the technology is more common than the method mentioned in Reference [14]. The simulated results of synthetic models reveal that the magnetic gradient tensor inversion method can be accurately employed to locate the magnetic body according to borehole bottom anomalies. Concerning 3D models, only one borehole magnetic data can calculate the locations accurately. Moreover, the method was applied to interpreting the three-component magnetic data of No.18-2 drill in Daye iron mining area, Hubei province, and the results indicate that the deconvolution solutions of magnetic gradient tensor are concentrated on the 100 to 180 m and 500 to 550 m elevations that are in accordance with the drilling results. The result confirms the geological inference that there are two steps of iron ore bodies, which has practical significance in search for ore bodies at deeper locations in Daye iron mining area.
刘天佑, 高文利, 冯杰, 习宇飞, 欧洋. 井中三分量磁测的梯度张量欧拉反褶积及应用[J]. 物探与化探, 2013, 37(4): 633-639.
LIU Tian-you, GAO Wen-li, FENG Jie, XI Yu-fei, OU Yang. EULER DECONVOLUTION OF BOREHOLE THREE-COMPONENT MAGNETIC GRADIENT TENSOR AND ITS APPLICATION. Geophysical and Geochemical Exploration, 2013, 37(4): 633-639.
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