用时间切片法建立三维偏移速度场

3—D MIGRATION VELOCITY FIELD BUILDING UP WITH TIME SLICE METHOD

三维偏移是三维资料处理中的关键步骤。除了偏移方法本身之外,影响三维偏移效果的另一个重要因素就是三维偏移速度场。人机交互系统为重建三维偏移速度场提供了新的手段。目前国内许多探区多采用“构造层法”建立三维速度场,本文认为“构造层法”操作复杂、工作量大,不适合复杂构造区和逆掩断块区的速度处理。本文介绍了在CGG的INTERBASE系统上用“切片法”建立三维偏移速度场的方法和步骤。经实际应用证明,新方法操作简便、适应性强,是一种行之有效的处理速度的方法。

3-D migration is a key step during 3-D data processing. Besides the migratoin method, another important factorthat influenced the effect of it is 3-D migration velocity field which is provided with interactive system as a newmethod for rebuilding it. At present,'Tectonostratigraphic method' has been usually used to many domestic exploredareas for building the field. However, this paper shows that 'tectonostratigraphic method' is complicated for operationand have a lot of work to do, not suitable for processing velocities picked from complexing structure and overthrustblock districts. The paper presents the methods and steps of building 3-D migration velocity field with 'Slice Method'on INTERBASE system of CGG. It is indicated practically that this new method is easy for operation,a good adapt-ability and effective for the velocity processing.