A Microseismic Interferometry Localization Method Based on Instantaneous Phase Cross-correlation Weighting

Abstract

The invention discloses a microseismic interference positioning method based on instantaneous phase cross-correlation weighting. N seismic waves of microseismic events are obtained through N geophones, and the seismic waves are componentized; the geophones are combined one by one to form a non-repetitive wave detection. pair; calculate the time-domain cross-correlation waveform and instantaneous phase cross-correlation waveform in each component; weight each time-domain cross-correlation waveform and its corresponding instantaneous phase cross-correlation waveform in each component to obtain the corresponding weighted cross-correlation Waveform; in each component, the theoretical direct wave travel time difference is used to migrate and superimpose the corresponding weighted cross-correlation waveforms of each channel to obtain the interference imaging profile; according to the multiplication of the interference imaging profiles in multiple components, the comprehensive interference imaging profile is obtained to determine the microseismic The location of the event. Through the above method, the problem of the polarity change of the microseismic waveform caused by the complex source mechanism is solved, and the influence of high-amplitude noise on the time-domain cross-correlation and subsequent stacking calculation is reduced.

Description

technical field [0001] The invention relates to the technical field of microseismic monitoring and positioning, in particular to a microseismic interference positioning method based on instantaneous phase cross-correlation weighting. Background technique [0002] As the world's energy becomes increasingly severe, the focus of oil and gas exploration has gradually shifted from conventional oil and gas fields to unconventional oil and gas fields. Unconventional oil and gas fields are characterized by tightness and low permeability, and hydraulic fracturing technology is mainly used for exploration and development. Microseismic monitoring technology is one of the most effective methods for real-time monitoring of hydraulic fracturing effects. The basic process is that when the fracturing operation is carried out in the reservoir through the fracturing well, the ground stress changes to form fractures, accompanied by weak acoustic emission or seismic wave signals, and these sei...

AI Technical Summary

Problems solved by technology

Because this type of positioning method does not consider the influence of the complex focal mechanism on the amplitude and phase of the waveform, it may not be possible to obtain an accurate source location

At the same time, this kind of method needs to search the time of the earthquake and the location of the source at the same time, which will limit the accuracy and efficiency of positioning to a certain extent.

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