Method for eliminating ambient fields in transient electromagnetic data through ratio method

Abstract

The invention relates to the technical field of geophysical exploration, in particular to a method for eliminating ambient fields in transient electromagnetic data through a ratio method. The method can eliminate the ambient fields in the transient electromagnetic data and extract required abnormal-field data. The method includes the steps of (1) judging the distribution directions of the ambient fields along with measuring lines according to experiences, (2) carrying out mesh interpolations on the data in the X direction and the Y direction according to a rule, (3) getting a data average value of one measuring line according to the directions determined in the step (1), (4) comparing data values of measuring points on the measuring line with the average value to get the ratios, (5) repeatedly carrying out the step (3) and the step (4) on each measuring line, (6) drawing a graph through the ratios of all the measuring points, (7) judging whether the drawing results are consistent with the directions judged in the step (1) or not, (8) judging whether the ratios in the two directions are required to be combined or not, if the ratios in the two directions are required to be combined, combining the ratios according to a following formula, drawing the graph through the combined data, completing the whole process, and if the ratios in the two directions are not required to be combined, directly completing the whole process.

Description

1. Technical field: [0001] The invention relates to the technical field of geophysical exploration, in particular to a method for eliminating background fields in transient electromagnetic data by using a ratio method. 2. Background technology: [0002] The apparent resistivity processing results of transient electromagnetic, often due to some complex geological or environmental reasons, make the apparent resistivity distribution very related to the geological electrical background. In this case, the apparent resistivity that interpreters care about Anomalies will be hidden in the large-area formation electrical background information and cannot be reflected intuitively. Therefore, it is necessary to study solutions to highlight anomalies. 3. Contents of the invention: [0003] In order to solve the deficiencies in the above-mentioned background technology, the present invention provides a method for eliminating the background field in the transient electromagnetic data by...

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Problems solved by technology

[0002] The apparent resistivity processing results of transient electromagnetic, often due to some complex geological or environmental reasons, make the apparent resistivity distribution very related to the geological electrical background. In this case, the apparent resistivity that interpreters care about Anomalies will be hidden in the large-area electrical background information of the formation and cannot be reflected intuitively. Therefore, it is necessary to study the solution to highlight anomalies

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