Microseismic signal P-wave first arrival point comprehensive pickup method

Abstract

The invention discloses a microseismic signal P-wave first arrival point comprehensive pickup method, which comprises the following steps: inputting microseismic time series data; picking up a first threshold value trigger point k1 through an STA / LTA method; picking up a kurtosis maximum point k2 through a PAI-K method; picking up a self-correlation minimum value point k3 through an AIC method; and determining a P-wave first arrival point k through a comprehensive method: (1) when the k1 has no pickup, k=k3, and (2)when the k1 has pickup:1) if |k1-k3|<=a, k=k3, 2) if |k1-k2|<=a, and |k1-k3|>a, k=k2, and 3) if |k1-k2|>a and |k1-k3|>a, k=k1. The comprehensive pickup method effectively solves the technical problems that the number of no-pickup events is large and pickup precision is low in the STA / LTA method and that the pickup stability of the PAI-K method and the AIC method is poor. The method has the advantages of easy processing, high applicability and high accuracy and the like.

Description

technical field [0001] The invention belongs to the technical field of signal processing, and in particular relates to a method for comprehensively picking up the first arrival point of a P wave of a microseismic signal. Background technique [0002] As an advanced and effective means of regional disaster monitoring and prediction, microseismic monitoring technology has been widely used in mining engineering, oil and gas exploitation, slope stability and tunnel engineering at home and abroad. Microseismic monitoring technology mainly includes: monitoring network layout, data processing, and microseismic event location (Ge, 2005), and picking the P wave first arrival point of microseismic signals is one of the core tasks of data processing. At present, the first arrival point of P wave is mainly picked manually, but the efficiency of manual picking is low and it is easily affected by personal factors. For this reason, it is very important to develop a high-precision and stab...

AI Technical Summary

Problems solved by technology

The STA / LTA method utilizes the changes in the amplitude and frequency of the microseismic signal at the first arrival point of the P wave. This algorithm is simple and easy to understand, and the calculation speed is fast. The signal is easily triggered by noise in advance; when the threshold value is large, the microseismic signal may not be triggered or triggered late, resulting in a large error, so it is difficult to find a threshold value suitable for different waveforms

The PAI-K method and the AIC method make full use of the singularity of the microseismic signals before and after the first arrival of the P wave, and the picking accuracy is high ( image 3 and Table 2), but are susceptible to low signal-to-noise ratios, spikes, and tail oscillations ( figure 2 ), poor pickup stability

[0004] It can be seen that there are great limitations in the existing methods for picking the P-wave first arrival point of microseismic signals, and it is necessary to study an automatic picking method with high picking accuracy and good stability

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