Abstract：The precision of stack velocity and interval velocity provided by common NMO correction processing method can't meet the need of predicting the pre-drilling press.The key reason is that the method supposed that the seismic wave traveled in isotropic layered medium and the practical layer has anisotropic feature on the contrary.Therefore,taking VTI medium as underground layer model,the paper uses P-wave forward modeling,expounds Alkhalifah method,4-order moveout analysis method containing useful anisotropic parameters and parallel-shifted hyperbolic moveout analysis technique,using these methods to correct the P-wave non-hyperbolic moveout separately;meanwhile,the comparison of above mentioned results with the results of 4-order moveout correction and parallel-shifted hyperbolic moveout correction based on isotropic medium model;The correction for real data is carried out by using useful isotropic parameters of real rock samples presented by Mr. Thmen (1986) .The results showed that the moveout analysis method of VTI medium is also suitable for isotropic medium and can provide precise seismic velocity;using useful anisotropic parameter of VTI medium η can also describe isotropic horizontal layered medium;when the useful anisotropic parameter η is taken as less than 0.1,the characters of weak anisotropic layer can be better reflected,which the errors of trace correction in near and middle offset are only 1 sample interval.Finally,the paper gave two practical methods for calculating useful NMO velocity and useful anisotropic parameter η.
