【摘要】 本文针对近地表散射干扰,从建立噪声时距方程出发,通过计算噪声剩余时差,讨论了三维地震观测系统压制散射干扰的定量分析方法:①利用地震剖面、井资料、地质背景资料、地理信息确定目的层的深度、平均速度和主要噪声类型及其传播速度,在此基础上设计出多套观测系统;②根据激发点、接收点和散射源的大地坐标计算CMP道集中每道的位置关系,进而计算噪声的剩余时差;③计算工区内或某个子区内CMP的噪声压制特性,并绘制平面图,统计噪声压制特性的分布,进而绘制噪声压制特性图和频数分布图;④对各种观测系统应用噪声压制特性图和频数分布图进行综合分析,确定各观测系统的压噪效果,从而选择压噪能力较强的三维观测系统。数值计算和实际地震数据处理分析表明,文中所提压噪估算方法可用来定量估算三维地震采集观测系统的压噪能力,评价噪声压制特性,有利于优化三维观测系统参数。更多还原

【Abstract】 In view of near-surface scattered interference and starting from building noise time-distance equation,then paper discussed quantitative analyzing method for suppressing scattered interference of 3-D seismic geometry:①using seismic section,drilling data,geologic background data and geographic information to determine the depth of targets,average velocity and major noise types and propagating velocity,designing multi-set of geometry on that basis;②computing position relationship of each channel on CMP gather according to geodetic coordinates of shot point,receiver point and scattered source,and further computing the residual moveout of noise;③computing suppression character of noise on CMP gather in work zone or sub-work zone and drawing the map,making the distribution of noise-suppressed characters and further drawing noise-suppressed character chart and frequency-number distribution map;④using noise-suppressed character chart and frequency-number map for integrative analysis for different geometry and determining the noise-suppressed effect of different geometry,and 3-D geometry with stronger noise-suppressed capacity was selected on that basis.Numeric computation and real seismic data processing showed that noise-suppressed evaluation method mentioned in the paper is able to quantitatively evaluate the noise-suppressed capacity of 3-D seismic acquisition geometry and appreciate noise-suppressed character,which is of benefit to optimize the parameters of 3-D geometry.更多还原