页岩气地震勘探中页岩各向异性的地震模拟研究
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摘要
页岩的强各向异性特征挑战地震波传播数值模拟方法的精度极限,特别是易引起频散的高频波(>100Hz)传播的数值模拟.鉴于目前我国页岩气地震勘探主要以常规地震声波资料为主,本文首先介绍了一种VTI介质声波方程的任意偶数阶有限差分数值模拟方法,并讨论其稳定性条件和吸收边界条件.任意偶数阶的差分解可有效提高计算精度,压制数值频散噪声.针对页岩较强的各向异性特征,本文比较了不同模型的声波方程和VTI介质声波方程计算得到的地震响应.数值结果表明,各向异性对地震波的运动学(相位)和动力学(振幅)特性影响作用明显.因此,在页岩气地震勘探资料处理的各个环节必须充分考虑各向异性的影响,采取有别于常规油气勘探的处理流程和技术.
The accuracy of numerical methods is challenged by strong anisotropies shown by shale,especially for high-frequency components(>100 Hz).Since the shale gas exploration still employs the acoustic seismic data,we first introduce an artificial even-order differential solution to VTI acoustic wave equation in the paper.The high-order solution can improve the computational accuracy and suppress numerical dispersion effectively.To show the effect of strong anisotropy of shale,we compare the seismic response of VTI acoustic wave equation with that of acoustic wave equation for different models.Numerical results show that anisotropy has large influences on the kinetics(phases) and the dynamics(amplitudes) of seismic waves.We conclude that the anisotropy must be considered when processing seismic data.
引文
[1]张金川,徐波,聂海宽等.中国页岩气资源勘探潜力.天然气工业,2008,28(6):136-141.Zhang J C,Xu B,Nie H K,et al.Exploration potential of shale gas resources in China.NaturalG as Industry(in Chinese),2008,28(6):136-141.
    [2]张金川,姜生玲,唐玄等.我国页岩气富集类型及资源特点.天然气工业,2009,29(12):109-114.Zhang J C,Jiang S L,Tang X,et al.Accumulation types and resources characteristics of shale gas in China.Natural Gas Industry(in Chinese),2009,29(12):109-114.
    [3]Prasad M,Pal-Bathija A,Johnston M,et al.Rock physics of the unconventional.The Leading Edge,2009,28(1):34-38.
    [4]Delle P C,Dewhurst D,Sarout J.TI or not TI?Stress effects on shale anisotropy.14th International Workshop on Seismic Anisotropy,2010:41-42.
    [5]史謌,邓继新.地层条件下泥、页岩衰减各向异性研究.中国科学(D辑:地球科学),2005,35(3):268-275.Shi G,Deng J X.The attenuation anisotropy of mudstones and shales in subsurface formations.Science in China Series D:Earth Sciences,2005,48(11):1882-1890.
    [6]Franquet J,Patterson D,Moos D,et al.Advanced dipole borehole acoustic processing-Rock Physics and Geomechanics Applications.81st Ann.Internat Mtg.,Soc.Expi.Geophys.Expanded Abstracts,2011:1876-1871.
    [7]杨顶辉,滕吉文.各向异性介质中三分量地震记录的FCT有限差分模拟.石油地球物理勘探,1997,32(2):181-190.Yang D H,Teng J W.FCT finite difference modeling of three-component seismic records in anisotropic medium.Oil Geophysical Prospecting(in Chinese),1997,32(2):181-190.
    [8]Virieux J.P-SV wave propagation in heterogeneous media:Velocity-stress finite-difference method.Geophysics,1986,51(4):889-901.
    [9]Saenger E H,Gold N,Shapiro S A.Modeling the propagation of elastic waves using a modified finite-difference grid.Wave Motion,2000,31(1):77-92.
    [10]McGarry R,Pasalic D,Ong C.Anisotropic elastic modeling on a Lebedev grid:Dispersion reduction and grid decoupling.81st Ann.Internat Mtg.,Soc.Expi.Geophys.Expanded Abstracts,2011:2829-2833.
    [11]祝贺君,张伟,陈晓非.二维各向异性介质中地震波场的高阶同位网格有限差分模拟.地球物理学报,2009,52(6):1536-1546.Zhu H J,Zhang W,Chen X F.Two-dimensional seismic wave simulation in anisotropic media by non-staggered finite difference method.Chinese J.Geophys.(in Chinese),2009,52(6):1536-1546.
    [12]兰海强,刘佳,白志明.VTI介质起伏地表地震波场模拟.地球物理学报,2011,54(8):2072-2084.Lan H Q,Liu J,Bai Z M.Wave-filed simulation in VTI media with irregular free surface.Chinese J.Geophys.(in Chinese),2011,54(8):2072-2084.
    [13]李桂花,冯建国,朱光明.黏弹性VTI介质频率空间域准P波正演模拟.地球物理学报,2011,54(1):200-207.Li G H,Feng J G,Zhu G M.Quasi-P wave forward modeling in viscoelastic VTI meida in frequency-space domain.Chinese J.Geophys.(in Chinese),2011,54(1):200-207.
    [14]Alkhalifah T.Acoustic approximations for processing in transversely isotropic media.Geophysics,1998,63(2):623-631.
    [15]Thomsen L.Weak elastic anisotropy.Geophysics,1986,51(10):1954-1966.
    [16]Grechka V,Zhang L B,Rector J W.Shear waves in acoustic anisotropic media.Geophysics,2004,69(2):576-582.
    [17]Duveneck E,Milcik P,Bakker P M,et al.Acoustic VTI wave equations and their application for anisotropic reverse-time migration.78th Ann.Internat Mtg.,Soc.Expi.Geophys.Expanded Abstracts,2008:2186-2190.
    [18]Zhou H,Zhang G,Bloor R.An anisotropic acoustic waveequation for VTI media.68th EAGE Conference and Exhibition,2006:194-197.
    [19]Liu Y,Sen M K.A practical implicit finite-difference method:examples from seismic modelling.Journal of Geophysics and Engineering,2009,6(3):231-249.
    [20]Pei Z L,Fu L Y,Sun W J,et al.Anisotropic finite-difference algorithm for modeling elastic wave propagation in fractured coalbeds.Geophysics,2012,77(1):C13-C26.
    [21]Jin S W,Jiang F,Ren Y Q,et al.Comparison of isotropic,VTI and TTI reverse time migration:an experiment on BP anisotropic benchmark dataset.80th Ann.Internat Mtg.,Soc.Expi.Geophys.Expanded Abstracts,2010:3198-3203.
    [22]Berenger J P.A perfectly matched layer for the absorption of electromagnetic waves.Journal of Computational Physics,1994,114(2):185-200.
    [23]Komatitsch D,Martin R.An unsplit convolutional perfectly matched layer improved at grazing incidence for the seismic wave equation.Geophysics,2007,72(5):SM155-SM167.
    [24]Cerjan C,Kosloff D,Kosloff R,et al.A nonreflecting boundary condition for discrete acoustic and elastic waveequations.Geophysics,1985,50(4):705-708.
    [25]Bording R P.Finite difference modeling-nearly optimal sponge boundary conditions.74th Ann.Internat Mtg.,Soc.Expi.Geophys.Expanded Abstracts,2004:1921-1924.
    [26]陈颙,黄庭芳,刘恩儒.岩石物理学.合肥:中国科学技术大学出版社,2009.Chen Y,Huang T F,Liu E R.Rock Physics(in Chinese).Hefei:Press of University of Science and Technology of China,2009.
    [27]Kristek J,Moczo P,Archuleta R.Efficient methods to simulate planar free surface in the3D4th-order staggered-grid finite-difference schemes.Stud.Geophys.Geod.,2002,46(2):355-381.
    [28]Lan H Q,Zhang Z J.Comparative study of the free-surface boundary condition in two-dimensional finite-difference elastic wave field simulation.Journal of Geophysics and Engineering,2011,8(2):275-286.
    [29]Sun W J,Zhou B Z,Hatherly P,et al.Seismic wave propagation through surface basalts-implications for coal seismic surveys.Exploration Geophysics,2010,41(1):1-8.

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