Angle-domain common-image gather extraction based on elastic reverse time migration
XU Weiya1,2,3, ZHU Chenghong1,2,3, WEI Zhefeng1,2,3, ZHANG Xiaoyu4, DU Qizhen5
1. State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Beijing 100083, China; 2. SINOPEC Key Laboratory of Seismic Elastic Wave Technology, Beijing 100083, China; 3. SINOPEC Petroleum Exploration and Production Research Institute, Beijing 100083, China; 4. Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Qingdao, Shandong 266100, China; 5. Key Laboratory of Deep Oil and Gas, China University of Petroleum (East China), Qingdao, Shandong 266580, China
Abstract：Due to the coupling effect of P- and S-waves in the medium,multi-wave angle-domain common-image gathers (ADCIGs) encounter the problems such as energy crosstalk and low wavenumber noise in multicomponent seismic exploration. To solve the stress crosstalk problem in the construction of the Poynting vector of S-waves,this study uses the decoupled wave equation and pseudo-S-wave stress construction method to decouple the particle vibration velocity and stress,and the Poynting vectors of the P- and S-waves are constructed without energy crosstalk. Then,the PP-wave and PS-wave reflected angles are extracted given the Poynting vectors. On this basis,this paper proposes the PP-wave and PS-wave ADCIG extraction method based on the elastic reverse time migration (ERTM). Considering the low wavenumber noise in PP-wave ADCIGs,an angle attenuation superposition strategy for ADCIGs is proposed to improve the migration imaging accuracy. The model test verifies the correctness of the method.
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