复杂地形条件下波动方程叠前深度成像

复杂地形勘探越来越被人们所关注。直接从起伏地表开始的叠前深度偏移方法是对付复杂地表和复杂地质构造成像的有效手段。“波场上延”法能实现由非水平观测界面开始的偏移过程，解决起伏地形对地下构造成像的影响，并克服基于“零速层”(Beasley 和 Lynn,1992)［1］法在计算上的不稳定因素，具体实施时更加灵活。理论模型的试算表明，“波场上延”方法较“零速层”法有着明显的优势，较好地克服了起伏地形对地下构造成像的影响，取得了令人满意的效果，达到了波动方程基准面校正和深度成像的有机结合。

Pre-stack wave equation depth migration for irregular topography

Increasing efforts to seismic exploration in areas with irregular topography have been made. Pre stack depth migration which starts directly from undulating earth surface turns out to be a valid way to deal with irregular topography and complex geologic structures. In this paper we present a method which can realize depth imaging from irregular topography with conventional depth migration scheme. This flexible method can overcome the computational instability in Zero velocity layer proposed by Beasley and Lynn(1992). Numerical tests on theoretical models show that the method can effectively combine wave equation datuming with depth imaging. It has a great advantage over Zero velocity layer.