联合改进STA/LTA与MLoG算子的微震P波到时自动拾取方法

Automatic pickup of microseismic P-wave arrival based on improved STA/LTA and MLoG operators

在非常规低渗油气藏开发过程中,微震P波震相到时的精确拾取是实时监测诱导水力压裂动态变化的一项关键技术。然而,传统的STA/LTA震相拾取方法存在低效率、低精度等问题。为提高低信噪比微震事件到时拾取的准确性和分辨率,提出一种联合改进型STA/LTA算法和MLoG算子的微震P波震相到时自动拾取方法。先通过MLoG算子对微震数据进行滤波处理,以提高信号的信噪比;再利用改进的特征函数计算STA/LTA拾取微震P波到时。模拟数据和实际数据的验算结果表明,本方法不仅可实现低信噪比微震数据P波到时的自动拾取,而且所拾取的P波到时精度高、鲁棒性强。

In the development process of unconventional low-permeability oil and gas reservoirs,accurate picking of microseismic P-wave phases is a key technology for real-time monitoring of induced hydraulic fracturing dynamic changes.However,the traditional STA/LTA seismic phase picking method has such problems as low efficiency and low accuracy.In order to improve the accuracy and resolution of the picking of the arrival of microseismic events with low signal-to-noise ratio,this paper proposed an automatic pickup method for microseismic P-wave phase arrival that combines improved STA/LTA algorithm and MLoG operators.Firstly,the microseismic data were filtered by the MLoG operators to improve the signal-to-noise ratio of the signal.Then,the improved feature function was used to calculate the arrival time of the STA/LTA to pick up the microseismic P-wave.The verification results of simulated data and actual data show that the proposed method can realize the automatic pickup of P-wave arrival of the low signal-to-noise ratio microseismic data with high accuracy and strong robustness.