Amplitude compensated reverse time migration by the symplectic stereo-modeling method
The resolution of reverse time migration(RTM)results highly depends on the accuracy of the seis-mic wave simulation.In this paper,the symplectic stereo-modeling method(SSM)is used to solve the visco-acoustic wave equation in the Birkhoffian system and RTM with amplitude compensation is conducted.First,a Birkhoffian system is constructed from the visco-acoustic wave equation.For the system,the second-or-der symplectic separable Runge-Kutta method is used to advance the time,the stereo-modeling method(STEM)and the conventional finite difference method are used to discrete the spatial operators,respectively,and two methods are obtained correspondingly:SSM and conventional symplectic method(CSM).Then a se-ries of numerical properties of SSM and CSM are analyzed,including numerical dispersion analysis,comparison with analytical solution,efficiency comparison,and long-term calculation stability test,etc.The results show that the maximum numerical dispersion error of SSM is approximately 9％,while that of CSM method is ap-proximately 26％.SSM exhibits high calculation efficiency and stability for long-time calculation,whose calcu-lation efficiency is approximately twice that of CSM.Finally,the forward numerical simulation and RTM ex-periments are conducted through the application of three models.The results show that visco-acoustic RTM ima ging amplitude is higher than acoustic V-RTM(attenuated data),and it can obtain imaging amplitude similar to acoustic A-RTM(un-attenuated data).For reservoir model,SSM has higher imaging accuracy and smaller nu-merical dispersion than CSM.
visco acoustic wave equationamplitude compensationsymplectic methodreverse time migration(RTM)numerical dispersion
万方数据
维普
