A fast VTI model building method using model based moveout

Typically VTI model parameter estimation is achieved through multiple iterations of depth migration, residual moveout estimation, and linearized tomography. In this paper we discuss a method to reduce the effort of migration and residual moveout estimation by applying local approximations to the imaging and modeling operators using model based moveout, which is a mapping between imaged specular reflections in initial and updated models. This allows for very efficient imaging and model testing, so that multiple iterations of linearized tomography or generalized iterative inversion can be applied. In this paper, model based moveout is combined with joint tomography to build an efficient workflow suitable for estimating Thomsen parameters and for early depth velocity model building. The method is demonstrated for a synthetic well and for a dual-sensor data set from the Gulf of Mexico.