基于相位编码的Fourier变换波动方程三维地震照明分析  

3D Fourier transform wave-equation-based seismic illumination analysis with phase encoding

作　　者：孙伟家[1,2] 符力耘[1] 胡善政 崔永福[4] 

机构地区：[1]中国科学院地质与地球物理研究所地球深部重点实验室,北京100029 [2]中国科学院研究生院,北京100049 [3]川庆钻探工程公司地球物理勘探公司,成都610213 [4]中国石油塔里木油田分公司勘探开发研究院,库尔勒841000

出　　处：《地球物理学进展》2011年第4期1249-1257,共9页Progress in Geophysics

基　　金：国家科技重大专项(2008ZX05023-005);国家重点基础研究发展计划(973计划)(2009CB219403)共同资助

摘　　要：复杂构造勘探是当前地震勘探的主要目标,提高深层信噪比和分辨率十分重要.地震照明分析是研究地震波能量在复杂构造中传播的有效手段,可指导观测系统设计进而提高野外数据采集和最终成像质量.本文发展了基于三维单程波动方程的地震照明方法,采用相位编码合成平面波源,一阶分离变量Fourier算子进行波场传播.阐述了照明和深度偏移之间的关系,说明照明阴影区对偏移结果的影响,并提出了照明分析的标准.由于初始速度模型的不准确,考察了照明分析对速度的敏感性.为提高目标区的照明度,提出目标激发和目标接收的概念,确定针对目标区的最佳激发位置及对应的最优接收区域.Complex structures are the main targets in current seismic exploration. Improving signal-to-noise ratio and resolution are important. Seismic illumination is a powerful tool for studying seismic energy propagations in complex structures, which can be applied to design seismic acquisition geometry and assess the quality of migration sections. In this paper, we develop 3D wave-equation-based seismic illumination, which the wavefield is extrapolated using first- order separation-of-variables Fourier propagator （SVSP1）. We present the relations between seismic illumination and depth migration to investigate the influence of shadow area of illumination on seismic migration. Then, two criterions of illumination are proposed to predict the quality of migration sections. Due to the inaccuracy of initial velocity model, we investigate the sensitivity of velocity error to seismic illumination. To enhance illumination strength in target area, the concepts of target-oriented excitation and target-oriented receiving is proposed. It can be applied to locate the optimum areas of shots and receivers.

关 键 词：地震照明分析.相位编码 FOURIER变换 波动方程 目标激发 目标接收 

分 类 号：P631[天文地球—地质矿产勘探]