Steep-Dip Time Migration in Lateral Velocity Media

Poststack 20 seismic depth migration methods have been a common practice for imaging in structurally complex regions. However, a good knowledge of interval velocities is required. An alternative approach to improve the accuracy of the imaging in an inhomogeneous earth is to use a time migration suitable for lateral varying velocity. This paper describes a numerical algorithm to perform a linear transformation of the scalar wave equation in media with varying velocity. We implement a nine-point star pattern finite difference scheme following Zhiming Li (1986; work which overcomes the dip limitations for the conventional paraxial operators and we show through synthetic and real examples the quallty of the imaljing without a proper knowledge of the velocity field