TTI介质Lebedev网格高阶有限差分正演模拟及波型分离

发布时间：2018-03-11 21:45

本文选题：TTI介质　切入点：正演模拟　出处：《石油地球物理勘探》2017年05期 　论文类型：期刊论文

【摘要】：针对TTI介质交错网格高阶有限差分正演模拟精度低及矢量波型分离不彻底的问题,发展了一种TTI介质Lebedev网格高阶有限差分正演模拟方法及矢量波型分离一体化处理流程。首先从一阶偏导数弹性波速度—应力方程出发,构建了TTI介质Lebedev网格高阶差分波场递推格式;然后借助Low-rank分解策略处理由极化矢量构成的空间—波数域分离算子,进而对速度分量实施纵、横波型分离;最终实现了Lebedev网格高阶差分方案与纵、横波分离模拟思路的有机结合,形成了复杂TTI介质高精度正演模拟与波型分离一体化处理流程。在实现方法的基础上,对均匀介质、层状介质以及复杂BP2007模型进行了正演及分离测试。计算结果表明:选取Lebedev网格高阶有限差分能够减小交错网格剖分方式带来的插值误差,从而获得高精度矢量波场;其次,通过应用Low-rank分解波型分离方法能够实现矢量波彻底分离,得到完全解耦的纵、横波场;文中方法对非均匀复杂模型具有良好的适应能力。
[Abstract]:In order to solve the problem of low precision of forward modeling and incomplete separation of vector wave pattern in TTI medium staggered grid high order finite difference modeling, A high order finite difference forward modeling method for Lebedev mesh in TTI medium and an integrated treatment process of vector wave separation are developed. Firstly, based on the first order partial derivative elastic wave velocity-stress equation, The high-order differential wave field recursive scheme of Lebedev mesh in TTI medium is constructed, and then the space-wavenumber domain separation operator composed of polarization vector is processed by Low-rank decomposition strategy, and the velocity components are separated by longitudinal and S-wave patterns. Finally, the organic combination of high-order difference scheme of Lebedev grid and the train of thought of longitudinal and S-wave separation simulation is realized, and the integrated processing flow of high precision forward modeling and wave type separation of complex TTI medium is formed. The forward modeling and separation test of layered medium and complex BP2007 model are carried out. The results show that the interpolation error caused by interlaced mesh generation can be reduced by Lebedev mesh high-order finite-difference method, and the high precision vector wave field can be obtained. The complete separation of vector waves can be achieved by using the Low-rank decomposition wave pattern separation method, and the fully decoupled longitudinal and shear wave fields can be obtained, and the proposed method has a good adaptability to the non-uniform complex model.
【作者单位】：中国石油大学(华东)地球科学与技术学院地球物理系;中海油研究总院;
【基金】：国家重点基础研究发展计划项目(2014CB239006) 国家自然基金项目(41274124) 中央高校科研业务费专项基金项目(R1401005A) 中国石油大学(华东)研究生创新工程资助项目(YCXJ2016005)联合资助
【分类号】：P631.4

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