3D magnetic data interpretation based on improved tilt angle
WANG Yanguo1, LUO Xiao1, DENG Juzhi1, YANG Yaxin1, WANG Cheng2, ZHANG Jin1
1. Key Laboratory of Fundamental Science on Radioactive Geology and Exploration Technology, East China University of Technology, Nanchang, Jiangxi 330013, China; 2. Xi'an Research Institute of China Coal Techno-logy and Engineering Group, Xi'an, Shaanxi 710077, China
Abstract:The delineation of magnetic anomaly and the division of structure are the important contents of the magnetic exploration.There is often no correspondence between the magnetic anomaly and the geologic body because of the influence of magnetization direction.At present, most methods for 3D magnetic interpretation require the magnetic anomaly reduced to the pole beforehand.However, it is difficult to achieve satisfactory results by reduction to the pole when a study area is relatively large or magnetic anomaly contains remanence.In addition, magnetic reduction to the pole may bring errors, which results in the failure of exploration.This paper proposes a 3D magnetic interpretation technique that can be directly used without reduced to the pole of magnetic anomaly.The proposed method is based on improved tilt angle, which can highlight the information of magnetic sources in the x and y directions.Model tests show that the proposed method can effectively identify the horizontal positions of the boundaries of prisms and sphere's centroid.Furthermore, the proposed method achieves better resolution and better identification of magnetic anomaly compared to other methods.The proposed method is applied to aeromagnetic data from Tamusu of Inner Mongolia, North China, and obtains detailed information of magnetic sources.The results have good correspondence with the geological data and seismic interpretation.In addition, the calculation results of the proposed method provide guides for delineation of hidden magnetic sources in the study area.
王彦国, 罗潇, 邓居智, 杨亚新, 王程, 张瑾. 基于改进tilt梯度的三维磁异常解释技术[J]. 石油地球物理勘探, 2019, 54(3): 685-691.
WANG Yanguo, LUO Xiao, DENG Juzhi, YANG Yaxin, WANG Cheng, ZHANG Jin. 3D magnetic data interpretation based on improved tilt angle. Oil Geophysical Prospecting, 2019, 54(3): 685-691.
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