Parallel Synthetic Source Record Reverse Time Migration

The project related to 2D reverse time is studied in this dissertation. It includes 2D phase-shift migration and forward modeling algorithms, 2D parallel prestack Fourier transform method modeling algorithm, 2D poststack Fourier transform method modeling algorithm, 2D parallel prestack reverse time migration of synthetic source record, 2D poststack reverse time migration of synthetic source record and residual migration velocity analysis by synthetic source records.Fourier transform method is also called pseudospectral method. The method calculates the spatial partial derivatives using fast Fourier transform and calculates the time partial derivative using second order central differencing. It speeds up computation by using shot record parallel programming. Phase shift migration method is a poststack migrating method in k x?ωdomain, This paper theoretically explaines the principle of phase shift migration method and gives the tests of the models.The reverse time migration method of synthetic source record based on the wave equation realized the time differencing of the reverse time migration and the reverse time propagation in the space of the sound wave using the two-way non-reflecting wave equation. The shot sources and source records can be synthesized by using three properties of the wave equation operator. The realization of parallel programming with MPI speeds up computation. The tests of the models which the paper gived show that the method is efficient and practical.Estimating the macro velocity model is considered to be the key step of prestack depth imaging procedures. We proposed residual migration velocity analysis by synthetic source records. The analytical equation is used to perform residual migration after prestack depth migration of synthetic source records. The correction formula is analytical, and it reduces the blindness of the velocity analysis.