Amplitude-preserved seismic migration based on double square root
Liu Ding-jin1, Yin Xing-yao2
Department of Geophysical Exploration, Geo-Resource and Information Institute, China University of Petroleum, Dongying City, Shandong Province, 257022, China
Abstract：The paper presented a method of amplitude-preserved prestack depth migration based on double square root equation.Firstly, starting from the amplitude-preserved equation of single square root operator and combining the amplitude-preserved up-going wavefield with down-going wavefield to approximately represent full acoustic wavefield, then, deducing one-way wave equation defined by double squave root operator; according to perturbation theory, the velocity field is divided into constant velocity background in layer and velocity-changed disturbance to compute time-shifted values of migration and correction coefficients of amplitude for depth continuation of wavefield in whole uniform layer as well as in separate layers, obtaining final continuation value of wavefield and fulfilling the formula transformation from common-shot domain to CMP domain.It is shown by the tests of theoretical model and real data processing, the method not only has higher computational efficiency and imaging precision, but also can show the amplitude information reflecting underground reflection coefficients correctly, benefit to analyze the AVO/AVA seismic attributes, providing accurate seismic data for lithologic identification and reservoir prediction.
