方位—角度域Kirchhoff叠前时间偏移成像  

Azimuth-angle domain Kirchhoff pre-stack time migration

作　　者：程玖兵[1] 马在田[1] 

机构地区：[1]同济大学海洋与地球科学学院

出　　处：《石油地球物理勘探》2010年第5期674-682,共9页Oil Geophysical Prospecting

基　　金：国家自然科学基金(40704022);国家863重点项目(2008AA093001);海洋地质国家重点实验室基金(MG20080205);中石化科技部共同资助

摘　　要：针对目前广泛使用的Kirchhoff叠前时间偏移,本文提出一种适用于各向同性介质和VTI介质的方位—角度域成像方法。其算法核心在于合理地估计地震射线的双程走时、平均方位角和局部入射角,再基于脉冲响应叠加原理获得三维空间的成像数据体和五维空间的方位—角度域共成像点道集。它的优势主要在于能获得高质量的三维角度域共成像点道集,且便于利用侧向散射能量改善对三维断层、倾斜界面和裂缝等特殊地质体的描述,是宽方位三维地震资料的高精度成像、属性分析和储层描述的有效方法。二维各向同性介质和SEG/HessVTI模型合成数据试验揭示了文中所述几种角度域成像算法的精度差异。三维断层模型合成数据成像结果表明,本文方法可合理描述反射时差、振幅随方位角和入射角的变化。Regarding the widely used Kirchhoff pre-stack time migration,a new azimuth-angle domain imaging method which fits both isotropic media and VTI media was proposed in this paper. The key of the algorism includes reasonable estimation of the two-way time for the seismic ray,average azimuth and local incidence angle,and then based on impulse response stacking principle the imaged 3D data volume and 5D azimuth-angle domain common imaging point gather were acquired. The algorithm's main advantages lies in its ability to obtain high quality common imaging point gather in 3D angle domain,and to utilize sidewise scattering energy in improving the description for 3D faults,slant interface,fractures and other special geological bodies. The new algorithm could provide excellent solution for more and more high resolution imaging projects,attribute analysis projects and reservoir characterization projects in wide azimuth 3D seismic data. The synthetic data test for SEG/Hess VTI model in 2D Isotropic Media revealed the accuracy difference for the several angle domain imaging algorithms which were described in this paper. The synthetic data imaging results for 3D fault model show that the algorithm presented in this paper could reasonably describe the reflection time difference and the amplitude variations with the azimuth and the incidence angle.

关 键 词：角度域成像 叠前时间偏移 平均方位角 局部入射角 数据面元化 

分 类 号：P631.4[天文地球—地质矿产勘探]