The Research And Comparison Of 2-D Post-Stack Migration Method

Because of the complexity of underground structure, such as the phenomenon of ubiquitous stratum gurgitation, faults, stratum extinguish, and steep obliquity stratum, which always make the folded seismic wavefield be quite complex, these directly cause the falsehood of the imaging result and the reduction of transverse resolution. Migration process can make the incline reflection migrate to its true underground interface, making analysis of interference zone, making diffraction convergence, thereby can improve the transverse resolution. In this meaning, migration process can be used as a method of space deconvolution to improve the space resolution.In this article, basing on analyzing the principium of migration imaging, we have researched and compared several popular 2-D post-stack migration algorithms, including Kirchhoff integral migration, f-x domain and Fourier finite difference depth migration. Based on one-way wave equation of wavefield extrapolation, we have study the wavefield extra polation operator in f-x domain systematically. By applying the polyn -omial approximate expression of square root operator, we have calculated the finite difference operator in f-x domain and Fourier finite difference operator in mixed domain of f-x domain and requency-wavenumber domain, and made comparison and appraisement for their calculation accuracy in the field and their lateral velocity variation adaptability and the computational efficiency. Based on the forerunners' research, we have applied visual language to make the velocity analysis, to make design of 45-90 finite difference forward and inversion, and Fourier finite differe -nce forward and inversion, and Kirchhoff integral migration. In depth migration and time migration we have carried out theoretical forward model and the test of actual data, and have proved accuracy of the algorithm further...