关于浮动基准面与起伏地表面的讨论  

Discussion on floating datum and rugged topography

作　　者：徐蔚亚[1] XU Wei-Ya(Sinopec Petroleum Exploration and Production Research Institute,Beijing 100083,China)

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083

出　　处：《物探与化探》2021年第1期95-101,共7页Geophysical and Geochemical Exploration

基　　金：国家科技重大专项(2017ZX05005-004);中石化科技部项目(P17021-4)。

摘　　要：确定起伏地表的空间位置是叠前深度域起伏地表偏移成像和速度建模成功的关键。浮动基准面本身就是一个起伏高程面,此外它还定义了CMP道集在其上进行基准面校正的规则。本文分析了确定浮动基准面的常用方法并明确了其在一般情况下所具有的物理意义,指出了即便是基于平均静校正法得到的浮动基准面,在一定条件下也可以直接用于起伏地表叠前深度域偏移成像和速度建模。此外,还讨论了在叠前深度域速度建模中错误地使用浮动基准面数据可能导致深度域成像结果中层位深度的移位和畸变的问题。Determination of the spatial position of the rugged topography surface is the key to the success of the pre-stack depth migration and velocity modeling on relief surface.The floating datum is not only a rugged topography elevation surface,but also defines the rules on which the CMP gathers are used for datum corrections.Analyzed the definition of the floating datum and clarified the physical meaning of the floating datum in general situations.The seismic data and velocity on floating datum can be directly used for topography pre-stack depth migration and velocity modeling under specific conditions.Discussed the situation that the improper use of floating datum data and corresponding RMS velocity in pre-stack depth migration and velocity modeling might result in shifting and distortion of the horizon layers in depth migration results.

关 键 词：浮动基准面 起伏地表 平均静校正量法 速度建模 叠前深度偏移 叠前时间偏移 

分 类 号：P631.4[天文地球—地质矿产勘探]