Reverse Time Migration(RTM)stands as one of the foremost advanced seismic wave imaging techniques.For elastic wave RTM,the separation of P-and S-waves prior to imaging is crucial to eectively prevent cross-talk interf...Reverse Time Migration(RTM)stands as one of the foremost advanced seismic wave imaging techniques.For elastic wave RTM,the separation of P-and S-waves prior to imaging is crucial to eectively prevent cross-talk interference between these wave modes.While more sophisticated P-and S-wave separation methods based on decoupled wave equations currently exist,the approach utilizing divergence and curl operators retains signicant practical value in elastic RTM due to its inherent simplicity in implementation and lower computational demand.However,existing P-and S-wave separation methods founded on divergence and curl operators lack a corresponding methodology for calculating decoupled P-and S-wave Poynting vectors.These decoupled Poynting vectors are vital as they can respectively indicate the propagation directions of P-and S-waves,and their application within elastic RTM can markedly improve imaging quality.This paper derives new formulas for calculating P-and S-wave Poynting vectors that correspond to the wave separation achieved through divergence and curl operators.This approach permits the accurate determination of P-and S-wave propagation directions without altering the original wave equations and has been applied to elastic RTM,ensuring higher computational efciency throughout the imaging process.Imaging test results from both the Graben and Marmousi models demonstrate that,compared to traditional coupled Poynting vectors,the decoupled P-and S-wave Poynting vectors proposed herein achieve superior suppression of migration noise and artifacts in elastic RTM.Furthermore,they facilitate accurate S-wave polarity correction,leading to clearer imaging interfaces in migration proles and more reliable overall results.The methodology presented in this paper broadens the application scenarios for elastic RTM under current computational resource constraints and is poised to stimulate further development of P-and S-wave separation methods based on divergence and curl operators within the eld of RTM.展开更多
基金the National Natural Science Foundation of China(Grant No.42574160)the Natural Science Foundation of Huzhou(Grant No.2024YZ41)+2 种基金the Open Fund(Grant No.36750000-24-FW0399-0011)of SINOPEC Key Laboratory of Geophysicsthe Basic Scientific Research Fund of the Institute of Earthquake Prediction,China Earthquake Administration(Grant No.CEAIEF2024030205)supported by the Center for Computational Science and Engineering at Southern University of Science and Technology.
文摘Reverse Time Migration(RTM)stands as one of the foremost advanced seismic wave imaging techniques.For elastic wave RTM,the separation of P-and S-waves prior to imaging is crucial to eectively prevent cross-talk interference between these wave modes.While more sophisticated P-and S-wave separation methods based on decoupled wave equations currently exist,the approach utilizing divergence and curl operators retains signicant practical value in elastic RTM due to its inherent simplicity in implementation and lower computational demand.However,existing P-and S-wave separation methods founded on divergence and curl operators lack a corresponding methodology for calculating decoupled P-and S-wave Poynting vectors.These decoupled Poynting vectors are vital as they can respectively indicate the propagation directions of P-and S-waves,and their application within elastic RTM can markedly improve imaging quality.This paper derives new formulas for calculating P-and S-wave Poynting vectors that correspond to the wave separation achieved through divergence and curl operators.This approach permits the accurate determination of P-and S-wave propagation directions without altering the original wave equations and has been applied to elastic RTM,ensuring higher computational efciency throughout the imaging process.Imaging test results from both the Graben and Marmousi models demonstrate that,compared to traditional coupled Poynting vectors,the decoupled P-and S-wave Poynting vectors proposed herein achieve superior suppression of migration noise and artifacts in elastic RTM.Furthermore,they facilitate accurate S-wave polarity correction,leading to clearer imaging interfaces in migration proles and more reliable overall results.The methodology presented in this paper broadens the application scenarios for elastic RTM under current computational resource constraints and is poised to stimulate further development of P-and S-wave separation methods based on divergence and curl operators within the eld of RTM.
