三维观测系统属性均匀性的定量分析

A uniformity quantitative method for 3D geometry attributes

在三维观测系统设计中,面元内覆盖次数、炮检距分布和方位角分布等直接影响观测系统属性均匀性。若相邻面元内覆盖次数相同、炮检距分布不均匀,则面元内的叠加振幅就存在差异。目前对观测系统属性均匀性的分析多以定性分析图表示,本文在借鉴已有方法的基础上引入均值、方差及加权因子概念,改进了三维观测系统炮检距均匀性的定量分析方法;利用该改进方法分析了三维观测系统参数对炮检距均匀性的影响,还通过模型正演评估了观测系统参数对叠加成像剖面的振幅和频率均匀性的作用。研究结果表明,炮检距均匀性与振幅或频率均匀性吻合较好,因此本文改进方法能有效分析和评价三维观测系统属性均匀性。

Fold distribution,offset distribution and azimuth distribution in a bin have direct effects on geometry attributes in 3D seismic survey design.If two adjacent bins have the same fold but different offsets,this non-uniform offset distribution brings some stack amplitude diversity in the adjacent bins.At present,3D geometry attribute uniformity of the most analytical methods is expressed by qualitative analysis chart.We introduce in this paper a uniformity quantitative analysis method for offset distribution by average value,square deviation and weighting factor.The paper analyses effects on offset distribution uniformity of different 3D geometry parameters by the proposed uniformity quantitative analysis method.Furthermore,the paper analyses effects on seismic stack amplitude or frequency uniformity of different 3D geometry parameters by the seismic wave modeling.The results show that offset distribution uniformity is in good agreement with seismic stack amplitude or frequency uniformity.Therefore this improved method can be considered as a useful tool for analyzing and evaluating 3D geometry attribute uniformity.