基于行波分离的VTI介质逆时偏移
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摘要
现阶段,各向同性介质假设已经不能满足复杂地质构造条件下的成像需求,忽略介质各向异性影响会使速度估计不准确,成像精度降低。为此,笔者从VTI介质一阶速度—应力方程出发,利用Poynting矢量特性对地震波进行方向行波分离,得出了基于上下行波分离的互相关成像条件,并将其应用在复杂VTI介质中。通过层状模型和SEG/EAGE岩丘模型测试验证了该算法的有效性以及在成像上的优越性;另外,当偏移速度不准确时,本文方法仍能够有效压制偏移噪声,成像质量更佳。
Seismic anisotropy characterized by velocity anisotropy will inevitably affect the kinematic characteristics of underground seismic waves.Ignoring the anisotropy of the media will result in inaccurate velocity extraction and thus affect the imaging of target region.In view of such a situation,the authors carried out a study of anisotropy in this paper.According to the first-order velocity stress equation in VTI media,the authors obtained the cross-correlation imaging condition based on wavefield separation which used Poynting vector.Then the authors applied it to complex VTI media,and demonstrated the validity and superiority of the algorithm by numerical experiments.This method produces better images with less noise even for inaccurate migration velocities.
Seismic anisotropy characterized by velocity anisotropy will inevitably affect the kinematic characteristics of underground seismic waves.Ignoring the anisotropy of the media will result in inaccurate velocity extraction and thus affect the imaging of target region.In view of such a situation,the authors carried out a study of anisotropy in this paper.According to the first-order velocity stress equation in VTI media,the authors obtained the cross-correlation imaging condition based on wavefield separation which used Poynting vector.Then the authors applied it to complex VTI media,and demonstrated the validity and superiority of the algorithm by numerical experiments.This method produces better images with less noise even for inaccurate migration velocities.
引文
[1] Tsvankin I,Thomsen L.Nonhyperbolic reflection moveout in anisotropic media[J].Geophysics,1994,59(8):1290-1304.
[2]吴国忱.各向异性介质地震波传播与成像[M].东营:中国石油大学出版社,2006.Wu G C. Seismic wave propagation and imaging in anisotropic media[M].Dongying:China University of Petroleum Press,2006.
[3]黄中玉,曲寿利,王于静,等.层状各向异性介质转换波克希霍夫叠前时间偏移[J].地球物理学报,2009,52(12):3109-3115.Huang Z Y,Qu S L,Wang Y J,et al. Kirchhoff prestack time migration of PS-wave data for the layered anisotropic medium[J].Chinese J. Geophys.(in Chinese),2009,52(12):3109-3115.
[4]周巍,王鹏燕,杨勤勇,等.各向异性克希霍夫叠前深度偏移[J].石油物探,2012,51(5):476-485.Zhou W,Wang P Y,Yang Q Y,et al. Research on anisotropic kirchhoff pre-stack depth migration[J]. GPP,2012,51(5):476-485.
[5] Hill N R. Prestack Gaussian-beam migration[J]. Geophysics,2001,66(4):1240-1250.
[6] Gray S H.Gaussian beam migration of common-shot records[J].Geophysics,2005,70(4):71-77.
[7]张凯,段新意,李振春,等.角度域各向异性高斯束逆时偏移[J].石油地球物理勘探,2015,50(5):912-918.Zhang K,Duan X Y,Li Z C,et al. Angle domain reverse time migration with Gaussian beams in anisotropic media[J].OGP,2015,50(5):912-918.
[8] Alkhalifah T.Acoustic approximations for processing in transversely isotropic media[J].Geophysics,1998,63(2):623-631.
[9] Klie H,Toro W.A new acoustic wave equation for modeling in anisotropic media[C]//Expanded Abstracts of the 71stAnnual SEG Meeting,Society of Exploration Geophysicists,2001:1171-1174.
[10] Zhou H,Zhang G,Bloor R.An anisotropic acoustic wave equation for VTI media[C]//68thEAGE Conference and Exhibition,2006a.
[11] Duveneck E P,Milcik P,Bakker P M,et al.Acoustic VTI wave equations and their application for anisotropic reverse-time migration[C]//Expanded Abstracts of the 78thAnnual SEG Meeting,Society of Exploration Geophysicists,2008:2186-2189.
[12] Hestholm S.Acoustic VTI modeling using high-order finite differences[J].Geophysics,2009,74(5):T67-T73.
[13] Fletcher R P,Du X,Fowler P J. Reverse time migration in tilted transversely isotropic(TTI)media[J].Geophysics,2009,74(6):WCA179-WCA187.
[14] Crawley S,Brandsberg-Dahl S,Mc Clean J,et al.TTI reverse time migration using the pseudo-analytic method[J]. The Leading Edge,2010,29(11):1378-1384.
[15] Zhan G,Pestana R C,Stoffa P L.Decoupled equations for reverse time migration in tilted transversely isotropic media[J]. Geophysics,2012,77(2):T37-T45.
[16]徐文才,李振春,王姣,等.基于拟声波一阶应力—速度方程的TI介质叠前逆时偏移[J].地球物理学进展,2016,31(2):836-844.Xu W C,Li Z C,Wang J,et al. TI medium reverse time migration based on quasi acoustic first-order velocity-stress equation[J].Progress in Geophysics(in Chinese),2016,31(2):836-844.
[17] Baysal E,Kosloff D D,Sherwood J W C. Reverse time migration[J].Geophysics,1983,48(11):1514-1524.
[18] Fletcher R P,Fowler P J,Kitchenside P,et al.Suppressing unwanted internal reflections in prestack reverse-time migration[J].Geophysics,2006,71(6):E79-E82.
[19] Yoon K,Marfurt K J. Reverse-time migration using the Poynting vector[J].Exploration Geophysics,2006,37(1):102-107.
[20] Guitton A,Kaelin B,Biondi B.Least-square attenuation of reverse time migration artifacts[C]//Expanded Abstracts of the 76thAnnual SEG Meeting,Society of Exploration Geophysicists,2006:2348-2352.
[21] Fei T W,Luo Y,Schuster G T.De-blending reverse-time migration[C]//Expanded Abstracts of the 80thAnnual SEG Meeting,Society of Exploration Geophysicists,2010:3130-3134.
[22] Liu F Q,Zhang G Q,Morton S A,et al.An effective imaging condition for reverse-time migration using wavefield decomposition[J].Geophysics,2011,76(1):29-39.
[23] Chen T,He B S.A normalized wavefield separation cross-correlation imaging condition for reverse time migration based on Poynting vector[J].Applied Geophysics,2014,11(2):158-166.
[24]陈可洋,陈树民,李来林,等.地震波动方程方向行波波场分离正演数值模拟与逆时成像[J].岩性油气藏,2014,26(4):130-136.Chen K Y,Chen S M,Li L L,et al.Directional one-way wave field separating numerical simulation of the seismic wave equation and reverse-time migration[J].Lithologic Reservoirs,2014,26(4):130-136.
[25]陈可洋.各向异性弹性介质方向行波波场分离正演数值模拟[J].岩性油气藏,2014,26(5):91-96.Chen K Y.Wave field separating numerical simulation of anisotropic elastic medium directional one-way wave[J]. Lithologic Reservoirs,2014,26(5):91-96.
[26]陈可洋.基于行波分离和角度域衰减的地震波叠前逆时成像条件[J].计算物理,2016,33(2):205-211.Chen K Y.Seismic wave pre-stack reverse-time migration imaging condition based on one-way wave field separation and angle domain attenuation[J].Chinese Journal of Computational Physics,2016,33(2):205-211.
[27]韩文功,王江川,李振春,等.基于Poynting矢量和方向行波波场分离的逆时偏移成像条件[J].地球物理学进展,2015,30(6):2660-2665.Han W G,Wang J C,Li Z C,et al.Reverse-time migration imaging conditions based on Poynting vector and directional one-way wave field separating[J].Progress in Geophysics,2015,30(6):2660-2665.
[28]李沁慈,刘国峰,孟小红,等.基于Poynting矢量的逆时偏移去噪[J].物探与化探,2015,39(6):1223-1232.Li Q C,Liu G F,Meng X H,et al. The denoising of reverse time migration based on the Poynting vector[J]. Geophysical&Geochemical Exploration,2015,39(6):1223-1232.
[29] Guo X,Huang J P,Li Z C,et al.Reverse time migration in complex TI media using wavefield decomposition[C]//Qingdao:International Geophysical Conference,2017:522-525.
[30] Han Q Y,Wu R S.Depth imaging in strongly heterogeneous VTI media[C]//SEG Technical Program Expanded Abstracts,2004:1061-1064.
[2]吴国忱.各向异性介质地震波传播与成像[M].东营:中国石油大学出版社,2006.Wu G C. Seismic wave propagation and imaging in anisotropic media[M].Dongying:China University of Petroleum Press,2006.
[3]黄中玉,曲寿利,王于静,等.层状各向异性介质转换波克希霍夫叠前时间偏移[J].地球物理学报,2009,52(12):3109-3115.Huang Z Y,Qu S L,Wang Y J,et al. Kirchhoff prestack time migration of PS-wave data for the layered anisotropic medium[J].Chinese J. Geophys.(in Chinese),2009,52(12):3109-3115.
[4]周巍,王鹏燕,杨勤勇,等.各向异性克希霍夫叠前深度偏移[J].石油物探,2012,51(5):476-485.Zhou W,Wang P Y,Yang Q Y,et al. Research on anisotropic kirchhoff pre-stack depth migration[J]. GPP,2012,51(5):476-485.
[5] Hill N R. Prestack Gaussian-beam migration[J]. Geophysics,2001,66(4):1240-1250.
[6] Gray S H.Gaussian beam migration of common-shot records[J].Geophysics,2005,70(4):71-77.
[7]张凯,段新意,李振春,等.角度域各向异性高斯束逆时偏移[J].石油地球物理勘探,2015,50(5):912-918.Zhang K,Duan X Y,Li Z C,et al. Angle domain reverse time migration with Gaussian beams in anisotropic media[J].OGP,2015,50(5):912-918.
[8] Alkhalifah T.Acoustic approximations for processing in transversely isotropic media[J].Geophysics,1998,63(2):623-631.
[9] Klie H,Toro W.A new acoustic wave equation for modeling in anisotropic media[C]//Expanded Abstracts of the 71stAnnual SEG Meeting,Society of Exploration Geophysicists,2001:1171-1174.
[10] Zhou H,Zhang G,Bloor R.An anisotropic acoustic wave equation for VTI media[C]//68thEAGE Conference and Exhibition,2006a.
[11] Duveneck E P,Milcik P,Bakker P M,et al.Acoustic VTI wave equations and their application for anisotropic reverse-time migration[C]//Expanded Abstracts of the 78thAnnual SEG Meeting,Society of Exploration Geophysicists,2008:2186-2189.
[12] Hestholm S.Acoustic VTI modeling using high-order finite differences[J].Geophysics,2009,74(5):T67-T73.
[13] Fletcher R P,Du X,Fowler P J. Reverse time migration in tilted transversely isotropic(TTI)media[J].Geophysics,2009,74(6):WCA179-WCA187.
[14] Crawley S,Brandsberg-Dahl S,Mc Clean J,et al.TTI reverse time migration using the pseudo-analytic method[J]. The Leading Edge,2010,29(11):1378-1384.
[15] Zhan G,Pestana R C,Stoffa P L.Decoupled equations for reverse time migration in tilted transversely isotropic media[J]. Geophysics,2012,77(2):T37-T45.
[16]徐文才,李振春,王姣,等.基于拟声波一阶应力—速度方程的TI介质叠前逆时偏移[J].地球物理学进展,2016,31(2):836-844.Xu W C,Li Z C,Wang J,et al. TI medium reverse time migration based on quasi acoustic first-order velocity-stress equation[J].Progress in Geophysics(in Chinese),2016,31(2):836-844.
[17] Baysal E,Kosloff D D,Sherwood J W C. Reverse time migration[J].Geophysics,1983,48(11):1514-1524.
[18] Fletcher R P,Fowler P J,Kitchenside P,et al.Suppressing unwanted internal reflections in prestack reverse-time migration[J].Geophysics,2006,71(6):E79-E82.
[19] Yoon K,Marfurt K J. Reverse-time migration using the Poynting vector[J].Exploration Geophysics,2006,37(1):102-107.
[20] Guitton A,Kaelin B,Biondi B.Least-square attenuation of reverse time migration artifacts[C]//Expanded Abstracts of the 76thAnnual SEG Meeting,Society of Exploration Geophysicists,2006:2348-2352.
[21] Fei T W,Luo Y,Schuster G T.De-blending reverse-time migration[C]//Expanded Abstracts of the 80thAnnual SEG Meeting,Society of Exploration Geophysicists,2010:3130-3134.
[22] Liu F Q,Zhang G Q,Morton S A,et al.An effective imaging condition for reverse-time migration using wavefield decomposition[J].Geophysics,2011,76(1):29-39.
[23] Chen T,He B S.A normalized wavefield separation cross-correlation imaging condition for reverse time migration based on Poynting vector[J].Applied Geophysics,2014,11(2):158-166.
[24]陈可洋,陈树民,李来林,等.地震波动方程方向行波波场分离正演数值模拟与逆时成像[J].岩性油气藏,2014,26(4):130-136.Chen K Y,Chen S M,Li L L,et al.Directional one-way wave field separating numerical simulation of the seismic wave equation and reverse-time migration[J].Lithologic Reservoirs,2014,26(4):130-136.
[25]陈可洋.各向异性弹性介质方向行波波场分离正演数值模拟[J].岩性油气藏,2014,26(5):91-96.Chen K Y.Wave field separating numerical simulation of anisotropic elastic medium directional one-way wave[J]. Lithologic Reservoirs,2014,26(5):91-96.
[26]陈可洋.基于行波分离和角度域衰减的地震波叠前逆时成像条件[J].计算物理,2016,33(2):205-211.Chen K Y.Seismic wave pre-stack reverse-time migration imaging condition based on one-way wave field separation and angle domain attenuation[J].Chinese Journal of Computational Physics,2016,33(2):205-211.
[27]韩文功,王江川,李振春,等.基于Poynting矢量和方向行波波场分离的逆时偏移成像条件[J].地球物理学进展,2015,30(6):2660-2665.Han W G,Wang J C,Li Z C,et al.Reverse-time migration imaging conditions based on Poynting vector and directional one-way wave field separating[J].Progress in Geophysics,2015,30(6):2660-2665.
[28]李沁慈,刘国峰,孟小红,等.基于Poynting矢量的逆时偏移去噪[J].物探与化探,2015,39(6):1223-1232.Li Q C,Liu G F,Meng X H,et al. The denoising of reverse time migration based on the Poynting vector[J]. Geophysical&Geochemical Exploration,2015,39(6):1223-1232.
[29] Guo X,Huang J P,Li Z C,et al.Reverse time migration in complex TI media using wavefield decomposition[C]//Qingdao:International Geophysical Conference,2017:522-525.
[30] Han Q Y,Wu R S.Depth imaging in strongly heterogeneous VTI media[C]//SEG Technical Program Expanded Abstracts,2004:1061-1064.
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