Microseismic Location Based on Interferometric Imaging and Hilbert-Huang Transform

摘要

For microseismic monitoring, the inaccurate microseismic source location will inevitably lead to misjudgment of the fracture geometry, thus reducing the reliability of microseismic monitoring. The location accuracy is greatly affected by the noise. Therefore, it is necessary and important to improve the accuracy and the robustness of the source location algorithm under the low SNR condition. Considering the non-stationarity of microseismic signals with strong random noise, a new microseismic event location approach based on interferometric imaging and Hilbert-Huang transform (HHT) is proposed. First, the synthetic microseismic signals are processed to the instantaneous energy spectrums and the Hilbert spectrums by HHT. Then, these two spectrums are respectively used as the characteristic functions of interferometric imaging method for microseismic source location and two different location methods are obtained. Finally, in homogeneous medium, the imaging results of the traditional approach and the proposed approach on synthetic low SNR datasets are analyzed and compared. The results demonstrate that the proposed approach can effectively suppress random noise and improves the location accuracy under the low SNR condition. These studies are of great significance to real time microseismic monitoring, especially for the surface monitoring.