The sensitivity of prestack depth migration to the ve-locity field
Mei Jinshun1, Wang Runqiu1, Yu Zhilong2, Li Zhengzhong3
1. Stay Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;
2. Geologic Research Center,GRI,BGP Inc.,CNPC,Zhuozhou,Hebei 072751,China;
3. College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China
Abstract：This paper describes the sensitivity of pres-tack depth migration(PreSDM)to the velocitymodel，and analyzes PreSDM processing outputs ofthree data sets with different velocities using thegeneralized screen propagator (USP) method of theMarmousi model.The following observations areobtained from our model tests.With low-passedfilter processing for the given velocity set，thePreSDM outputs are not sensitive to the high spa-tial wavenumbers within the velocity set.For dif-ferent velocity sets，especially with different lowerspatial wavenumbers among the velocity sets，thePreSDM outputs are greatly different.It meansthat PreSDM is sensitive to the lower spatial wave-number within the velocity sets.Smoothing thevelocity sets in space often has little improvementin PreSDM processing because it can hardly changethe lower spatial wavenumber, especially with er-rors in the velocity sets themselves.For one shotmigration processing，if the lower spatial wave-number velocity data for this shot has beenchanged during the velocity model buildingprocess，the PreSDM output may have great chan-ges.The ideas in this paper can be used to guidethe velocity model building for PreSDM.
梅金顺, 王润秋, 于志龙, 李正中. 叠前深度偏移对速度场敏感性分析[J]. 石油地球物理勘探, 2013, 48(3): 372-378.
Mei Jinshun, Wang Runqiu, Yu Zhilong, Li Zhengzhong. The sensitivity of prestack depth migration to the ve-locity field. OGP, 2013, 48(3): 372-378.
