VTI介质隐式有限差分平面波偏移  

IMPLICIT FINITE-DIFFERENCE PLANE WAVE MIGRATION IN VTI MEDIA

作　　者：韩利[1] 韩立国[1] 崔杰[1] 巩向博[1] 

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026

出　　处：《物探化探计算技术》2011年第2期115-121,105,共7页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：国家"973"项目(2007CB209603);国家863项目(2007AA060801)

摘　　要：这里研究了VTI(Vertical Transverse Isotropy)介质隐式有限差分(IFD)波场外推算子和VTI介质平面波偏移。在文中设计了VTI介质IFD波场外推算子,将Taylor分析法求得的差分系数,作为初始解,用非线性优化方法迭代求得算子系数。将设计的外推算子频散曲线和偏移脉冲响应与理论解进行了对比分析,验证出外推算子有较高的精度。从各向同性介质平面波偏移理论出发,结合VTI介质IFD波场外推算子,将平面波偏移推广到VTI介质中。对Hess VTI标准模型拟合数据进行偏移,偏移结果验证了平面波偏移在VTI介质中的有效性,以及在加强特定陡倾界面成像方面的优势。并且,与常规VTI介质叠前深度偏移相比,VTI介质平面波偏移在保证成像质量的前提下,大大减少了计算量,为各向异性偏移成像研究提供了新的技术思路。Implicit finite-difference (IFD) extrapolation operator and plane wave migration in VTI media are studied in this paper. We design VTI media IFD extrapolation operator, and obtain the differential coefficients by nonlinear optimization iteration method with Taylor expansion solution as the initial solution. We verify the high accuracy of the operater by comparing the dispersion curve and migration Impulse response of the IFD extrapolation operator with the theoretical solution. Combining the theory of plane wave migration in isotropic media with the IFD operator in VTI media, plane wave migration are extended to VTI media. Synthetic Hess VTI model data verifies the effectiveness of the method and the advantage on special steep reflectors imaging. Compared with conventional shot-profile migration in VTI media, plane wave migration largely reduces the computation cost with the same imaging quality, which provides a new way for anisotropic study.

关 键 词：平面波偏 VTI介质偏移 各向异性偏移 VTI介质波场外推 隐式有限差分算子 

分 类 号：P631.4[天文地球—地质矿产勘探]