基于相位编码的地震照明度分析  

Phase encoding-based seismic illumination analysis

作　　者：孙伟家[1] 符力耘[1] 碗学检[2] 

机构地区：[1]中国科学院地质与地球物理研究所 [2]中原油田物探公司采集方法研究所

出　　处：《石油地球物理勘探》2007年第5期539-543,共5页Oil Geophysical Prospecting

基　　金：国家科技部"973"项目(2006CB202306)资助。

摘　　要：地震照明分析是面向目标的地震正演技术。本文通过相位编码合成平面波源,采用单程波傅里叶有限差分(FFD)算子进行波场延拓,对地质目标体进行高效的面炮照明分析。全炮照明分析从全局考察能量在地下介质中的分布,大大提高了计算效率;单炮照明分析可以显示能量在局部范围的分布情况,克服了平面波源无空间局部性的缺点。综合全炮照明和单炮照明分析确定地质构造对地震能量传播的影响。对于能量较弱的目标区,利用照明统计方法,选择对目标区能量贡献大的最优炮点位置。通过对理论模型和桥口地区实际资料分析,表明该方法具有高效、快速和精度高的优点。Seismic illumination analysis is target-oriented seismic forward technique. Using phase encoding to synthesize plane wave source and adopting oneway wave Fourier finite-difference (FFD) operator to carry out wavefield continuation, the paper implemented the planar shot illumination analysis with high efficiency for geologic targets. The all shot illumination analysis can investigate globally the distribution of energy in subsurface medium, greatly improving the computational efficiency; single shot illumination analysis can show the distribution of energy in local range, overcoming the shortcoming of non-spatial locality in planar wave source. Integrative analysis of all shot illumination with single shot illumination can determine the influence of geologic structures on propagation of seismic energy. For the target zone with weak energy, we use illumination statistical approach and select the optimum shot positions having big energy contribution to target zone. The theoretical model and practical application and analysis in Qiaokou area showed that the approach is characteristic of high efficiency,speed and precision.

关 键 词：地震照明度 相位编码 平面波合成 地震正演 面向目标 傅里叶有限差分 

分 类 号：P618.130.8[天文地球—矿床学]