Microearthquake event detecting and positioning method and apparatus

Abstract

The embodiment of the invention provides a microearthquake event detecting and positioning method and apparatus. The method includes the following steps: obtaining P-wave correction time differences and S-wave correction time differences between each grid in a grid structure of a template event and different observation stations, and also obtaining P-wave cross correlation coefficients and S-wave cross correlation coefficients of the template event; determining first superposed cross correlation coefficients of each grid at different times on the basis of the P-wave cross correlation coefficients between P-waves of the template event and each observation station at different times, the S-wave cross correlation coefficients between S-waves of the template event and each observation station at different times, and the P-wave correction time differences and the S-wave correction time differences between each grid and the different observation stations; determining position and time of a microearthquake event corresponding to the template event according to the first superposed cross correlation coefficients of each grid at different times and a first preset threshold value. In this way, a microearthquake event low in signal to noise ratio can be detected and positioned accurately.

Description

technical field [0001] Embodiments of the present invention relate to oil and gas seismic exploration technology, in particular to a method and device for detecting and locating microseismic events. Background technique [0002] In the process of oil and gas seismic exploration, it is necessary to obtain fracturing results relatively quickly to evaluate the fracturing effect, and then adjust the mining plan in time. and locate the location of microseismic events. [0003] The detection of microseismic events in existing wells is based on the method of STA / LTA (Short Term Average / Long Term Average, long and short time window energy ratio method). For the single well monitoring system, the information of P wave or S wave azimuth angle is also used to invert to determine the location of microseismic events. [0004] However, the number of detected microseismic events and the accuracy of locating microseismic events in the existing technology strongly depend on the signal-to-n...

AI Technical Summary

Problems solved by technology

[0005] Embodiments of the present invention provide a method and device for detecting and locating microseismic events, which are used to solve the technical problem that the existing technology cannot accurately detect and locate the position of microseismic events with low signal-to-noise ratio

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