地震资料处理中不同基准面的定义及其解释

Definition and Interpretation for Different Base-Levels in Seismic Data Processing

对目前应用较多的几种基准面的定义、静校正方法、静校正量的计算及其对应的表层结构、速度场关系展开分析讨论。认为:CMP参考面为对应地表高程的平滑面,且未改变表层速度结构关系;VSP的时间、深度、速度关系可与CMP参考面下的地层关系相对应。给出了对应于不同基准面的地震资料VSP的时间、深度、速度的校正计算方法,以及地震资料时深转换和构造成图的方法,为解释阶段的VSP标定和时深转换构造成图的应用提供参考。

This paper presents the analyses and discussions of several base-levels definitions, static correction methods and static computations as well as corresponding relations to individual surface structures and velocity fields that are commonly applied in production nowadays. The study shows that the common midpoint （CMP） reference surface is the smooth surface Corresponding to the surface elevation without changing relations to the surface structure and velocity. The relations among the time, depth and velocity of vertical seismic profile （VSP） can be corresponded to the stratigraphic relations under CMP reference surface one by one. The methods for correction and computation of VSP＇s time, depth and velocity based on different base-levels＂ seismic data and the method for related time-depth conversion and structural mapping are proposed, which provide bases for VSP calibration, time-depth conversion and structural mapping in stage of seismic data processing.