PRESTACK MIGRATION BASED ON ASYMMETRIC WAVE-EQUATION EXTRAPOLATION

摘要

Prestack wave-equation migration has been popular in recent years. One-way wave equation migration and two-way wave-equation migration are the two choices for applying the wave-equation migration. They have different advantages and disadvantages. In this investigation, a combined version of these methods is developed, called asymmetric wave-equation migration. In this migration scheme, the source wave-field is extrapolated using the one-way wave-equation or two-way wave-equation, but the receiver wave-field is extrapolated based on the wave-equation being different from the former. By analyzing theoretically, the asymmetric wave-equation migration scheme can greatly reduce computation time compared with two-way wave-equation migration. Meanwhile, detailed comparisons between different migration schemes have been performed. The results show that the proposed migration scheme can work better than the two-way wave-equation migration, with less computation time and noise; thus, it is a new choice when we select migration schemes.