Walkaway VSP资料的AVO处理方法研究
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摘要
用Walkaway VSP资料进行AVO分析是一种可靠的解决方法,它不依赖于困扰地面地震的很多不确定因素(如衰减、传播损失、多次波和球面扩散等)。当井中三分量检波器离目的层顶界面很近时,下行直达P波和目的层顶界面入射P波的传播路径相差很小,下行直达P波的振幅和目的层顶界面入射P波的振幅近似相等,上行P-P反射波的振幅和下行直达P波的振幅之比就可以被看作是这个界面的P-P波反射系数。
用弹性波动方程对4类含气砂岩模型在VSP观测系统下进行了AVO正演,与Zoeppritz方程精确计算出的反射系数进行对比,结果显示出很好的一致性,证明在变偏移距VSP观测系统下用共反射点道集进行AVO分析是可行的,为野外实际资料的AVO分析作好了准备。
论文指出了传统三分量偏振方法不能对振幅进行保真处理;提出了用非线性最优化方法实现分时参数反演波场分离方法,并分别对模拟记录和野外实际记录进行了波场分离试算,对共炮点道集的两个分量数据进行振幅保真的参数反演波场分离,成功的分离出单纯的上行反射P-P波和上行反射P-SV波,为后续AVO真振幅提取奠定了基础。
设计了一套应用Walkaway VSP资料进行AVO分析的数据处理流程,用水平多层模型模拟记录验证了其可靠性,用反射系数近似原理求取了含气砂岩目的层的上行P-P波和上行P-SV波的反射系数,与Zoeppritz方程精确计算出的反射系数显示出很好的一致性,证明数据处理流程没有引入对振幅的影响,并将处理流程应用于野外实际资料的处理中。
反射系数近似原理可以消除大多数波场传播作用的影响,也最小化了由炮点径向和检波器耦合引起的不确定性,可以很好的估算目的层顶界面的反射系数。同时应用P-P和P-SV反射波进行AVO研究有助于对地层岩性的识别,转换波中所附加的信息对提升地震波场的解释和分析作用巨大。
It is a reliable solution for AVO analysis using Walkaway VSP data. It does not depend on a number of uncertainties which affect the surface seismic geometry (attenuation, transmission losses, multiples, and spherical spreading). When the geophone is near the interface, the travel path of the reflected wave is small, the amplitude of the recorded P-wave direct arrival and the amplitude of the P-wave incident on the interface are approximately equal. The reflection coefficient can be obtained by taking the ratio of the incident and reflected wave amplitudes.
AVO forward for four class model gas-bearing sandstones modeling has been implemented based on VSP geometry. There is reasonable agreement between the processed data amplitudes and the theoretical Zoeppritz equation solution for the interface. It is feasible for AVO analysis in the Offset VSP geometry using common reflection point gathers. It is ready for AVO analysis of the actual data field.
The traditional three-component synthesis method can not maintain the amplitude. The basic principles of Analysis methods are discussed in detail, three components synthesis problem and wavefield separation are also discussed. A parametric inversion technique developed was used for the wavefield separation. Wavefield separation is applied to the vertical and radial gathers of each offset position individually. These data are separated into the two modes of wave propagation (the upgoing P and S wavefields). The separation has worked well with the minor exception of some noise.
A processing flow has been developed to process the multioffset VSP data for AVO analysis. It is necessary to test this flow on synthetic data. The model is that of a gas-saturated sandstone encased in shale. The processing flow is tested for true amplitude recovery by comparing the picked amplitude from the top of the sand reflection with the theoretical Zoeppritz equation solution for the interface. There is reasonable agreement between the processed data amplitudes and the theoretical amplitudes. It proves that no relative amplitude changes are introduced between the upgoing and downgoing wavefields. A brief overview of the processing flow is given for the synthetic VSP data with a more detailed description following for the multioffset VSP field data.
The reflection coefficient is independent of most wave propagation effects. This ratio process also minimizes uncertainties caused by source directivity and source or receiver coupling. It can be a good estimate of the P-P reflection coefficient of the interface. The result is that both P-P and P-SV reflections can be used jointly in an AVO study to help understand the subsurface rock properties. Thus the additional information in the converted wave reflections should enhance the interpretation and analysis of the seismic wavefield.
用弹性波动方程对4类含气砂岩模型在VSP观测系统下进行了AVO正演,与Zoeppritz方程精确计算出的反射系数进行对比,结果显示出很好的一致性,证明在变偏移距VSP观测系统下用共反射点道集进行AVO分析是可行的,为野外实际资料的AVO分析作好了准备。
论文指出了传统三分量偏振方法不能对振幅进行保真处理;提出了用非线性最优化方法实现分时参数反演波场分离方法,并分别对模拟记录和野外实际记录进行了波场分离试算,对共炮点道集的两个分量数据进行振幅保真的参数反演波场分离,成功的分离出单纯的上行反射P-P波和上行反射P-SV波,为后续AVO真振幅提取奠定了基础。
设计了一套应用Walkaway VSP资料进行AVO分析的数据处理流程,用水平多层模型模拟记录验证了其可靠性,用反射系数近似原理求取了含气砂岩目的层的上行P-P波和上行P-SV波的反射系数,与Zoeppritz方程精确计算出的反射系数显示出很好的一致性,证明数据处理流程没有引入对振幅的影响,并将处理流程应用于野外实际资料的处理中。
反射系数近似原理可以消除大多数波场传播作用的影响,也最小化了由炮点径向和检波器耦合引起的不确定性,可以很好的估算目的层顶界面的反射系数。同时应用P-P和P-SV反射波进行AVO研究有助于对地层岩性的识别,转换波中所附加的信息对提升地震波场的解释和分析作用巨大。
It is a reliable solution for AVO analysis using Walkaway VSP data. It does not depend on a number of uncertainties which affect the surface seismic geometry (attenuation, transmission losses, multiples, and spherical spreading). When the geophone is near the interface, the travel path of the reflected wave is small, the amplitude of the recorded P-wave direct arrival and the amplitude of the P-wave incident on the interface are approximately equal. The reflection coefficient can be obtained by taking the ratio of the incident and reflected wave amplitudes.
AVO forward for four class model gas-bearing sandstones modeling has been implemented based on VSP geometry. There is reasonable agreement between the processed data amplitudes and the theoretical Zoeppritz equation solution for the interface. It is feasible for AVO analysis in the Offset VSP geometry using common reflection point gathers. It is ready for AVO analysis of the actual data field.
The traditional three-component synthesis method can not maintain the amplitude. The basic principles of Analysis methods are discussed in detail, three components synthesis problem and wavefield separation are also discussed. A parametric inversion technique developed was used for the wavefield separation. Wavefield separation is applied to the vertical and radial gathers of each offset position individually. These data are separated into the two modes of wave propagation (the upgoing P and S wavefields). The separation has worked well with the minor exception of some noise.
A processing flow has been developed to process the multioffset VSP data for AVO analysis. It is necessary to test this flow on synthetic data. The model is that of a gas-saturated sandstone encased in shale. The processing flow is tested for true amplitude recovery by comparing the picked amplitude from the top of the sand reflection with the theoretical Zoeppritz equation solution for the interface. There is reasonable agreement between the processed data amplitudes and the theoretical amplitudes. It proves that no relative amplitude changes are introduced between the upgoing and downgoing wavefields. A brief overview of the processing flow is given for the synthetic VSP data with a more detailed description following for the multioffset VSP field data.
The reflection coefficient is independent of most wave propagation effects. This ratio process also minimizes uncertainties caused by source directivity and source or receiver coupling. It can be a good estimate of the P-P reflection coefficient of the interface. The result is that both P-P and P-SV reflections can be used jointly in an AVO study to help understand the subsurface rock properties. Thus the additional information in the converted wave reflections should enhance the interpretation and analysis of the seismic wavefield.
引文
Aki, K.I. and Richards, P.G., Quantitative Seismology-theory and method [M]: W.H. Freeman and Company, 1980, 153-154.
Blias, E.A., VSP wavefield separation. Wave-by-wave Approach., SEG/Houston Annual Meeting, 2005, 2609-2612.
Blias, E.A., VSP wavefield separation: Wave-by-wave optimization approach, Geophysics, 2007, 72, 47-55.
Blias, E.A., AVO-VSP velocity analysis and 3-C 3-D VSP automatic wavefield separation, SEG Meeting, 2008, 3350-3354.
Blias, E.A., Interval VTI and orthorhombic anisotropic parameter estimates from walkaway/3D VSP Data, SEG Meeting, 2009, 211-215.
Burnett, R., Seismic amplitude anomalies and AVO analysis at Mestena Grande Field, Jim Hogg Co., Texas, Geophysics, 1990, 55, 1015-1025.
Bortfeld, R., Approximation to the reflection and transmission coefficients of plane longitudinal and transverse waves, Geophysical Prospecting, 1961, 9, 485-502.
Chacko, S., Porosity identification using amplitude variations with offset: examples from South Samatra, Geophysics, 1989, 54, 942-951.
Coulombe, C., Stewart, R. and Jones, M., AVO processing and interpretation of VSP data, Can J Explor Geophys, 1996, 32, 41-62.
Dankbaar, J.W.M., Vertical seismic profiling separation of P and S waves, Geophys. Prosp., 1987, 35, 803-814.
DiSiena, J.P., Gaiser, J.E., and Corrigan, D., Horizontal component and shear wave analysis of three component VSP data, in Toksoz, N.N., and Stewart, R. R., Eds., Vertical siesmic profiling Pan B: Advanced concepts: Geophysical Press, 1984.
Esmersoy, C., Inversion of P and SW waves from multicomponent offset vertical seismic profiles, Geophysics, 1990, 55, 39-50.
Frazier, C.W., and Zaengle J.F., Correlation and interpretation of P-P and P-SV reflections across the Zamora Gas Field in YoIo County, California: Joint SEGfEAEG Summer ResearchWorkshop - How useful is AVO analysis?, Technical Program and Abstracts, 1992, 66-77.
Gaiser, I.E., DiSiena, J.P., and Fix, J.E., VSP: Fundamentals of the downgoing wavefield and applications that imporve CDP data interpretaion, in Toksoz, N.N., and Stewart, R. R., Eds., Vertical siesmic profiling Part B: Advanced concepts: Geophysical Press, 1984.
Koefoed, O., On the effect of Poisson's ratios of rock strata on the reflection coefficients of plane waves: Geophys. Prosp., 1955, 3, 381-387.
Koefoed O.Reflection and transmission coefficients for plane longitudinal incident waves.Geophysical Prospecting, 1962, 10, 304-351.
Lawton, D.C., and Nazar, B.D., Thin bed tuning and AVO: a case history of coupled P-P and P-SV interpretation: SEG/EAEG AVO Workshop, Expanded Abstracts, 1992, 90-96.
Leany, S.W., Anisotropy and AVO from walkaways, SEG Expanded Abstracts 13, 1994, 105-109.
Leany, S.W., Anisotropic vector plane wave decomposition for 3D VSP data, SEG Meeting, 2002.
Leany, S.W., Inversion of microseismic data by least-squares time reversal and waveform fitting, SEG Meeting, 2008, 1347-1351.
Leany, S.W., M. D. Sacchi, Least-squares migration with dip-field regularization: application to 3D VSP data, SEG Meeting, 2008, 2864-2868.
Leany, S.W., Polar anisotropy from walkway VSPs, TLE, 2008, 10, 1242-1250.
Leany, S.W. and Esmersoy, C., Parametric wavefield decomposition of offset VSP wave fields: 59th Ann. Int. Mtg. Soc. Expl. Geophys., Expanded Abstracts, 1989, 26-29.
Leany, S.W., Sayers, C.M. and Miller, D.E., Analysis of multiazimuthal VSP data for anisotropy and AVO, 1999, 64, 1172-1180.
Leany, S.W., and Ulrych, T.J., Compound median filtering applied to sonic logs:57th Ann. Int. Mtg. Soc. Expl. Geophys., Expanded Abstracts, 1987, 23-26.
Lee, M.W., and Balch, A.H., Computer processing of vertical seismic profile data: 1983, 48, 272-287.
Mazzotti, A., Amplitudes, phase, and frequency versus offset applications, Geophys. Prosp. 1991, 39, 863-886.
Muskat, M. and Meres, M.W., Reflection and transmission coefficients for plane waves in elasticmedia: Geophysics, 1940, 5, 149-155.
Ostrander, W.J., Plane wave reflection coefficients for gas sands at non normal angles of incidence: Geophysics, 1984, 49, 1637-1648.
Ross, C.P., Incomplete AVO near salt structure: Geophysics, 1992, 57, 543-553.
Rutherford, S.R., and Williams, R.H., Amplitude-versus-offset variations in gas sands: Geophysics, 1989, 54, 680-688.
Swan, H.W., Amplitude-versus-offset measurement errors in a finely layered medium: Geophysics, 1991, 56, 41-49.
Shuey, R.T., A simplification to the Zoeppritz equations, Geophysics, 1985, 50, 609-614.
Tatham, R.H., and Krug, E.H., Vp/Vs Interpretation: Developments in Geophysical Methods-6., Ed. A.A. Fitch, Elsevier Applied Science Publications, London, New York, 1985.
Walden, A.T., Making AVO sections more robust: Geophys. Prosp. 1991, 39, 915-942.
Young, B.C., and Braile, L.W., A computer program for the application of Zoeppritz's amplitude equations and Knott's energy equations: Seismological Society of America Bulletin, 1976, 66, 1881-1885.
Yilmaz, O., Seismic Data Processsing, Soc. of Expl. Geophys., 1987, 506.
崔基泰. VSP三分量资料合成的新方法.石油地球物理勘探,1994,29(3):368-375.
段云卿,皮金云,刘兵,等.三分量小折射表层调查研究.石油地球物理勘探,2008,43(6):652-655
郭全仕,张卫华,黄华昌,等.高精度拉冬变换方法及应用.石油地球物理勘探,2005,40(6):622-627
胡广书.数字信号处理.北京:清华大学出版社,2003
何樵登.地震勘探原理和方法.北京:地质出版社,1986
何樵登,杨宝俊译,Eи加尔比林著.地震助探偏振法.北京:石油工业出版社,1989
黄中玉,谈大龙,徐亦鸣,等.多分量地震数据矢量保真度分析.石油物探,2005,44(3):206-208
李庆忠.走向精确勘探的道路.北京:石油工业出版社,1993
刘喜武,刘洪.波动方程地震偏移成像方法的现状与进展.地球物理学进展,2002,17(4):582-591
陆基孟.地震勘探原理.山东:石油大学出版社,1993
牟永光,等.地震数据处理方法.北京:石油工业出版社,2007
牟永光,裴正林.三维复杂介质地震数值模拟.北京:石油工业出版社,2007
牛滨华,孙春岩.半空间均匀各向同性单相固体弹性介质与地震波传播.北京:地质出版社,2005
R. E.谢里夫,L. P.吉尔达特.勘探地震学.北京:石油工业出版社,1999
王家映编.地球物理反演理论.北京:高等教育出版社,2002
王彦春,余钦范等.交互迭代折射静校正方法.石油物探,1998,37(2):63-70
魏修成等.变速视慢度波场分离.石油地球物理勘探,1993,28(4):418-429
姚姚.地震波场与地震勘探.北京:地质出版社,2006
曾有良,等.基于高分辨率Radon变换的VSP波场分离方法.石油物探,2007年,46(2):115-117
朱光明.垂直地震剖面方法.北京:石油工业出版社出版,1992
Blias, E.A., VSP wavefield separation. Wave-by-wave Approach., SEG/Houston Annual Meeting, 2005, 2609-2612.
Blias, E.A., VSP wavefield separation: Wave-by-wave optimization approach, Geophysics, 2007, 72, 47-55.
Blias, E.A., AVO-VSP velocity analysis and 3-C 3-D VSP automatic wavefield separation, SEG Meeting, 2008, 3350-3354.
Blias, E.A., Interval VTI and orthorhombic anisotropic parameter estimates from walkaway/3D VSP Data, SEG Meeting, 2009, 211-215.
Burnett, R., Seismic amplitude anomalies and AVO analysis at Mestena Grande Field, Jim Hogg Co., Texas, Geophysics, 1990, 55, 1015-1025.
Bortfeld, R., Approximation to the reflection and transmission coefficients of plane longitudinal and transverse waves, Geophysical Prospecting, 1961, 9, 485-502.
Chacko, S., Porosity identification using amplitude variations with offset: examples from South Samatra, Geophysics, 1989, 54, 942-951.
Coulombe, C., Stewart, R. and Jones, M., AVO processing and interpretation of VSP data, Can J Explor Geophys, 1996, 32, 41-62.
Dankbaar, J.W.M., Vertical seismic profiling separation of P and S waves, Geophys. Prosp., 1987, 35, 803-814.
DiSiena, J.P., Gaiser, J.E., and Corrigan, D., Horizontal component and shear wave analysis of three component VSP data, in Toksoz, N.N., and Stewart, R. R., Eds., Vertical siesmic profiling Pan B: Advanced concepts: Geophysical Press, 1984.
Esmersoy, C., Inversion of P and SW waves from multicomponent offset vertical seismic profiles, Geophysics, 1990, 55, 39-50.
Frazier, C.W., and Zaengle J.F., Correlation and interpretation of P-P and P-SV reflections across the Zamora Gas Field in YoIo County, California: Joint SEGfEAEG Summer ResearchWorkshop - How useful is AVO analysis?, Technical Program and Abstracts, 1992, 66-77.
Gaiser, I.E., DiSiena, J.P., and Fix, J.E., VSP: Fundamentals of the downgoing wavefield and applications that imporve CDP data interpretaion, in Toksoz, N.N., and Stewart, R. R., Eds., Vertical siesmic profiling Part B: Advanced concepts: Geophysical Press, 1984.
Koefoed, O., On the effect of Poisson's ratios of rock strata on the reflection coefficients of plane waves: Geophys. Prosp., 1955, 3, 381-387.
Koefoed O.Reflection and transmission coefficients for plane longitudinal incident waves.Geophysical Prospecting, 1962, 10, 304-351.
Lawton, D.C., and Nazar, B.D., Thin bed tuning and AVO: a case history of coupled P-P and P-SV interpretation: SEG/EAEG AVO Workshop, Expanded Abstracts, 1992, 90-96.
Leany, S.W., Anisotropy and AVO from walkaways, SEG Expanded Abstracts 13, 1994, 105-109.
Leany, S.W., Anisotropic vector plane wave decomposition for 3D VSP data, SEG Meeting, 2002.
Leany, S.W., Inversion of microseismic data by least-squares time reversal and waveform fitting, SEG Meeting, 2008, 1347-1351.
Leany, S.W., M. D. Sacchi, Least-squares migration with dip-field regularization: application to 3D VSP data, SEG Meeting, 2008, 2864-2868.
Leany, S.W., Polar anisotropy from walkway VSPs, TLE, 2008, 10, 1242-1250.
Leany, S.W. and Esmersoy, C., Parametric wavefield decomposition of offset VSP wave fields: 59th Ann. Int. Mtg. Soc. Expl. Geophys., Expanded Abstracts, 1989, 26-29.
Leany, S.W., Sayers, C.M. and Miller, D.E., Analysis of multiazimuthal VSP data for anisotropy and AVO, 1999, 64, 1172-1180.
Leany, S.W., and Ulrych, T.J., Compound median filtering applied to sonic logs:57th Ann. Int. Mtg. Soc. Expl. Geophys., Expanded Abstracts, 1987, 23-26.
Lee, M.W., and Balch, A.H., Computer processing of vertical seismic profile data: 1983, 48, 272-287.
Mazzotti, A., Amplitudes, phase, and frequency versus offset applications, Geophys. Prosp. 1991, 39, 863-886.
Muskat, M. and Meres, M.W., Reflection and transmission coefficients for plane waves in elasticmedia: Geophysics, 1940, 5, 149-155.
Ostrander, W.J., Plane wave reflection coefficients for gas sands at non normal angles of incidence: Geophysics, 1984, 49, 1637-1648.
Ross, C.P., Incomplete AVO near salt structure: Geophysics, 1992, 57, 543-553.
Rutherford, S.R., and Williams, R.H., Amplitude-versus-offset variations in gas sands: Geophysics, 1989, 54, 680-688.
Swan, H.W., Amplitude-versus-offset measurement errors in a finely layered medium: Geophysics, 1991, 56, 41-49.
Shuey, R.T., A simplification to the Zoeppritz equations, Geophysics, 1985, 50, 609-614.
Tatham, R.H., and Krug, E.H., Vp/Vs Interpretation: Developments in Geophysical Methods-6., Ed. A.A. Fitch, Elsevier Applied Science Publications, London, New York, 1985.
Walden, A.T., Making AVO sections more robust: Geophys. Prosp. 1991, 39, 915-942.
Young, B.C., and Braile, L.W., A computer program for the application of Zoeppritz's amplitude equations and Knott's energy equations: Seismological Society of America Bulletin, 1976, 66, 1881-1885.
Yilmaz, O., Seismic Data Processsing, Soc. of Expl. Geophys., 1987, 506.
崔基泰. VSP三分量资料合成的新方法.石油地球物理勘探,1994,29(3):368-375.
段云卿,皮金云,刘兵,等.三分量小折射表层调查研究.石油地球物理勘探,2008,43(6):652-655
郭全仕,张卫华,黄华昌,等.高精度拉冬变换方法及应用.石油地球物理勘探,2005,40(6):622-627
胡广书.数字信号处理.北京:清华大学出版社,2003
何樵登.地震勘探原理和方法.北京:地质出版社,1986
何樵登,杨宝俊译,Eи加尔比林著.地震助探偏振法.北京:石油工业出版社,1989
黄中玉,谈大龙,徐亦鸣,等.多分量地震数据矢量保真度分析.石油物探,2005,44(3):206-208
李庆忠.走向精确勘探的道路.北京:石油工业出版社,1993
刘喜武,刘洪.波动方程地震偏移成像方法的现状与进展.地球物理学进展,2002,17(4):582-591
陆基孟.地震勘探原理.山东:石油大学出版社,1993
牟永光,等.地震数据处理方法.北京:石油工业出版社,2007
牟永光,裴正林.三维复杂介质地震数值模拟.北京:石油工业出版社,2007
牛滨华,孙春岩.半空间均匀各向同性单相固体弹性介质与地震波传播.北京:地质出版社,2005
R. E.谢里夫,L. P.吉尔达特.勘探地震学.北京:石油工业出版社,1999
王家映编.地球物理反演理论.北京:高等教育出版社,2002
王彦春,余钦范等.交互迭代折射静校正方法.石油物探,1998,37(2):63-70
魏修成等.变速视慢度波场分离.石油地球物理勘探,1993,28(4):418-429
姚姚.地震波场与地震勘探.北京:地质出版社,2006
曾有良,等.基于高分辨率Radon变换的VSP波场分离方法.石油物探,2007年,46(2):115-117
朱光明.垂直地震剖面方法.北京:石油工业出版社出版,1992