Wave packet superposition microseism ground location method

Abstract

The invention relates to a wave packet superposition microseism ground location method. The method comprises the following steps of (a) dividing a model into a plurality of grids, and giving a threshold value for a number of iteration and an external enveloping superposition value; (b) selecting a detector, calculating a time for a microseism event in a designated grid to reach each designated detector, and correcting the time difference; (c) getting a root-mean-square amplitude of the corrected signal of the detector, solving external envelop, and adding the external envelops together to get an external enveloping superposition channel; (d) changing the grid, calculating the external enveloping superposition channel of the detector in a novel designated grid, traversing all grids to get the external enveloping superposition channel set; (e) picking up the microseism event on the external enveloping superposition channel set, and determining a position of the microseism; (f) calculating a signal-to-noise ratio of the picked microseism event; (g) repeating the steps of (b) to (f) until meeting the number of the iteration to obtain multiple microseism event positions, and counting the percentage of the times on each position in the total times; and (h) determining the microseism event exceeding the threshold value as a microseism valid event.

Description

technical field [0001] The invention relates to geophysical prospecting microseismic positioning technology, more specifically, relates to a wave packet superposition microseismic ground positioning method based on multiple constraint conditions. Background technique [0002] In the processing of microseismic data, the key step is to accurately pick up effective microseismic events, and the ultimate goal is to accurately locate the position of effective microseismic events, so as to perform fracture prediction. The microseismic positioning in the well is mainly to determine the hypocenter location by picking up the first arrival waves of effective events and using the first arrival time to perform inversion. However, for the microseismic data received on the ground, the energy of the effective signal is weak and completely submerged in the noise. The signal-to-noise ratio of the microseismic section is extremely low, and it is impossible to pick up the first arrival of the m...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the problems of the traditional energy stacking positioning method in the use of ground microseismic data, the present invention proposes a microseismic ground positioning method based on multi-constraint wave packet stacking, through microseismic records root mean square amplitude outer envelope stacking The method solves the polarity inversion problem caused by the geometric positional relationship between the receiver point and the source point, and introduces multiple constraints such as wave packet stacking channel signal-to-noise ratio and statistical methods, which greatly improves the identification of microseismic ground monitoring events and positioning accuracy

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