高阶交错网格非稳态相移叠后深度偏移

High order staggered grids non stationary phase shift method post stack depth migration

为更好地研究复杂构造和速度分布条件下地震资料的精确偏移.在波场模拟方面,本文采用了高阶交错网格有限差分[1]推导了二维各向同性介质声波方程的数值模拟公式.并给出了声波方程完全匹配层吸收边界[2-5](PML).在偏移方面,本文介绍了一种能适应介质速度横向变化的非稳态相移算子(NSPS)[6]及其叠后深度偏移方法.并对简单的四层模型和Marmousi模型进行试算.偏移结果表明,该方法可以有效地处理复杂条件下的各向同性介质声波偏移问题.

In order to the better study of complex structure and the accurate seismic data migration in condition of the velocity distribution, In the wave field simulation, deducing the two dimension isotropic medium of sound wave equation numerical simulation formulas using the high order staggered grid finite difference. The completely matched layer absorption boundary of the sound wave equation is given. In the migration, this paper introduces a non stationary phase shift operator （NSPS） which can to medium speed lateral changes and its post stack depth migration method. And the simple four layer model and Marmousi model is worked out. Migration results show that this method can effectively deal with the complex isotropic medium sound waves migration problem.