Microseismic signal identification with multichannel matching pursuit based on local coherence spectrum constraint
Cao Junhai1,2, Gu Hanming1,2, Shang Xinmin3
1. Hubei Subsurface Multi-scale Imaging Key Laboratory, China University of Geosciences(Wuhan), Wuhan, Hubei 430074, China;
2. Institute of Geophysics and Geomatics, China University of Geosciences(Wuhan), Wuhan, Hubei 430074, China;
3. Geophysics Research Institute, Shengli Oilfield Branch Co., SINOPEC, Dongying, Shandong 257022, China
Abstract：The multichannel matching pursuit (MCMP) is a lateral coherency-based approach which decomposes a trace into a series of atoms,and the atoms generated at an iteration has the same shift,frequency,scale,phase parameters,but different amplitude factor.However seismic signals are often directional.To make use of the directional feature,we propose a new algorithm,multichannel matching pursuit based on local coherence spectrum constrain.We test the proposed algorithm together with conventional MCMP on both synthetic and real microseismic data.In order to verify the accuracy and feasibility of the proposed algorithm,we pick and analyze first breaks with short time average/long time average (STA/LTA) algorithm.The processing results show that the new multichannel matching pursuit algorithm improves significantly the microseismic data signal-to-noise ratio (SNR),and reduces microseismic event false detection to a certain extent.Also the peaks of STA/LTA algorithm are improved by about 1.2 times after processing.So the proposed algorithm can better identify microseismic signals than conventional MCMP.
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