Method and device for suppressing harmonic interference of microseismic monitoring data

Abstract

The invention relates to a method and a device for suppressing harmonic interference of microseismic monitoring data. The method comprises the following steps of acquiring microseismic data and sorting seismic data recorded by all geophone positions together to serve as a common-geophone gather; performing FFT (Fast Fourier Transform) transformation on each recording channel in the common-geophone gather to acquire frequency-domain seismic data; obtaining an amplitude spectrum by using the frequency-domain seismic data; performing multichannel median filtering on each frequency sampling of the amplitude spectrum to obtain an amplitude spectrum after the first-time median filtering; performing multipoint median filtering on each recording channel of the amplitude spectrum after the first-time median filtering to obtain an amplitude spectrum after the second-time median filtering; obtaining filter coefficients by using the amplitude spectrum after the first-time median filtering and the amplitude spectrum after the second-time median filtering; performing filter processing on the frequency-domain seismic data by using the filter coefficients, and performing inverse FFT transformation on the result obtained by filter processing to obtain time-domain microseismic data subjected to harmonic interference suppressing.

Description

technical field [0001] The invention relates to the technical field of seismic exploration data processing, in particular to a method and device for suppressing harmonic interference of microseismic monitoring data. Background technique [0002] In unconventional oil and gas hydraulic fracturing projects or geothermal utilization projects, acoustic emission events generated during rock fractures can be obtained through microseismic monitoring, and the location of these events can reveal information such as the spatial distribution of underground rock fractures, which can be used for hydraulic fracturing, etc. It provides the most direct help for engineering parameter optimization and effect evaluation. [0003] At present, there are many microseismic monitoring methods, whether it is in-well monitoring or ground array monitoring, the data obtained generally have a low signal-to-noise ratio. Effective microseismic signals generally have weak energy and short duration, while v...

AI Technical Summary

Problems solved by technology

At present, there is no highly targeted denoising method for microseismic records. Most of them follow the filtering method in seismic exploration. While filtering and suppressing noise, it also has an obvious suppression effect on microseismic signals, thereby reducing the accuracy of microseismic positioning.

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