库车大北构造带三维叠前深度偏移处理解释技术

3D Prestack Depth Processing and Interpretation in Dabei Structure Belt, Kuqa Depression

叠前深度偏移已成为解决复杂地区地震成像的有力工具,但与叠前时间偏移相比其速度敏感性较强,这是制约其应用的技术瓶颈。库车大北地区位于塔里木盆地库车坳陷克拉苏构造带西段,地表结构和地下构造的双重复杂使得该区地震成像难度很大。介绍了处理解释结合,多重约束叠前深度偏移速度建模方法,通过表层调查、层析反演、井资料约束、非地震资料等多信息的融合应用,建立叠前深度偏移速度场,采用各向异性叠前深度偏移方法,较好地解决了该区复杂构造成像问题。

Prestack depth migration has become an effective approach to solving seismic imaging problems in complex area. However, it is more sensitive to velocity as compared with prestack time migration, which constrains its application. Dabei area is located in the west of Kelasu structure belt of Kuqa Depression, Tarim Basin, where seismic imaging is very difficult because of complicated topography and subsurface structure. This paper introduces the integration of procession and interpretation, and the prestack depth migration velocity modeling method under multi-constraints. Based on the integration and application of surface investigation, tomographyic inversion, well constraints, non-seismic data and other information, velocity field is built, and then anisotropic prestack depth migration is used to image complicated structure. It has successfully solved the imaging problem in the area.