应用正演模拟分析近地表黏弹性对深层缝洞储层地震波衰减及成像的影响
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摘要
近地表沙层的黏弹特性引起的地震波能量及频率的吸收衰减不容忽视。本文基于黏弹性介质波动方程正演模拟技术,研究了近地表不同Q值情况下地震波穿过黏弹介质后的地震波场特征,通过波场频谱特征分析了影响地震波能量及频率吸收衰减的因素,即Q值越小、激发子波的主频越高、传播距离越远的地震波能量及主频吸收衰减越严重。在此基础上建立起伏地表沙层缝洞型模型,研究近地表沙层对中深部储层反射波的衰减及对缝洞型储层成像的影响,对实际地震资料的振幅、频率的恢复补偿以及提高分辨率具有一定意义。
Seismic absorption and attenuation of energyand frequency caused by visco-elasticity nearsurface sand layers cannot be ignored.In this article,we discuss seismic wave field generated by seismic wave travelling through visco-elastic medium with different Qby forward modeling based on visco-elastic wave equation.We also analyze factors affecting seismic energy and frequency absorption and decay through wave field spectral analysis.The smaller the Qvalue is,the higher dominant frequency the wavelet has,seismic energy and frequency absorption and decay are more serious and with the propagation distance increases.Finally,building fractured-vuggy models,we analyze nearsurface sand influence on wave attenuation and deep fractured-vuggy reservoir imaging.It is proved that this meaningful work is helpful for amplitude and frequency compensation and data resolution enhancement.
Seismic absorption and attenuation of energyand frequency caused by visco-elasticity nearsurface sand layers cannot be ignored.In this article,we discuss seismic wave field generated by seismic wave travelling through visco-elastic medium with different Qby forward modeling based on visco-elastic wave equation.We also analyze factors affecting seismic energy and frequency absorption and decay through wave field spectral analysis.The smaller the Qvalue is,the higher dominant frequency the wavelet has,seismic energy and frequency absorption and decay are more serious and with the propagation distance increases.Finally,building fractured-vuggy models,we analyze nearsurface sand influence on wave attenuation and deep fractured-vuggy reservoir imaging.It is proved that this meaningful work is helpful for amplitude and frequency compensation and data resolution enhancement.
引文
[1]李庆忠.走向精确勘探的道路.北京:石油工业出版社,1994.
[2]黄凯,徐群洲,杨晓海等.地震波能量的衰减及其影响因素.新疆石油地质,1997,18(3):212-216.Huang Kai,Xu Qunzhou,Yang Xiaohai et al.Attenuation of seismic wave energy and its influencing factors.Xinjiang Petroleum Geology,1997,18(3):212-216.
[3]凌云.大地吸收衰减分析.石油地球物理勘探,2001,36(1):1-8.Ling Yun.Analysis of attenuation by earth absorption.OGP,2001,36(1):1-8.
[4]凌云,高军,吴琳.时频空间域球面发散与吸收补偿.石油地球物理勘探,2005,40(2):176-182.Ling Yun,Gao Jun and Wu Lin.Compensation for spherical dispersion in time-frequency-space domain.OGP,2005,40(2):176-182.
[5]刘建华,胥颐,郝天珧.地震波衰减的物理机制研究.地球物理学进展,2004,19(1):1-6.Liu Jianhua,Xu Yi,Hao Tianyao.Study on physical mechanism of the seismic wave attentuation.Progress in Geophysics,2004,19(1):1-6.
[6]周发祥,宁鹏鹏,刘斌等.吸收衰减对地震分辨率的影响.石油地球物理勘探,2008,43(增刊2):84-87.Zhou Faxiang,Ning Pengpeng,Liu Bin et al.Influence of attenuation by absorption on seismic resolution.OGP,2008,43(S 2):84-87.
[7]钱绍瑚,高建华,谷永兴等.地层吸收衰减模型的制作及补偿方法的研究.石油地球物理勘探,1998,33(增刊1):18-24.
[8]Carcione J M.Seismic modeling in viscoelastic media.Geophysics,1993,58(1):110-120.
[9]Robertsson J O A,Blanch J O and Symes W W.Viscoelastic finite-diffence modeling.Geophysics,1994,59(9):1444-1456.
[10]Arntsen B,Nebel A G and Amundsen L.Visco-acoustic finite-difference modeling in the frequency domain.Journal of Seismic Exploration,1998,7(1):45-64.
[11]Saenger E H and Bohen T.Finite-difference modeling of viscoelastic and anisotropic wave propagation using the rotated staggered grid.Geophysics,2004,69(2):583-591.
[12]杜启振.各向异性黏弹性介质伪谱法波场模拟.物理学报,2004,53(12):4428-4434.Du Qizhen.Wavefield forward modeling with the pseudo-spectral method in viscoelastic and azimuthally anisotropic media.Acta Physica Sinica,2004,53(12):4428-4434.
[13]张智,刘财,邵志刚等.伪谱法在常Q黏弹介质地震波场模拟中的应用效果.地球物理学进展,2005,20(4):945-949.Zhang Zhi,Liu Cai,Shao Zhigang et al.The application of pseudo-spectral forward modeling of seismic wave field in constant Qviscoelastic medium.Progress in Geophysics,2005,20(4):945-949.
[14]宋常瑜,裴正林.井间地震黏弹性波场特征的数值模拟研究.石油物探,2006,45(5):508-513.Song Changyu and Pei Zhenglin.Numerical simulation of viscoelastic wavefield for crosshole seismic exploration.GPP,2006,45(5):508-513.
[15]牛滨华,孙春岩.黏弹介质与地震波传播.北京:地质出版社,2007.
[16]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,2005.
[17]成景旺,顾汉明,刘琳等.海上黏弹弹性介质FCT有限差分正演模拟.石油天然气学报,2011,33(12):83-87.Cheng Jingwang,Gu Hanming,Liu Lin et al.Flux correction transport(FCT)finite forward modeling for marine viscoelastic media.Journal of Oil and Gas Technology,2011,33(12):83-87.
[18]俞寿朋.高分辨率地震勘探.北京:石油工业出版社,1993.
[2]黄凯,徐群洲,杨晓海等.地震波能量的衰减及其影响因素.新疆石油地质,1997,18(3):212-216.Huang Kai,Xu Qunzhou,Yang Xiaohai et al.Attenuation of seismic wave energy and its influencing factors.Xinjiang Petroleum Geology,1997,18(3):212-216.
[3]凌云.大地吸收衰减分析.石油地球物理勘探,2001,36(1):1-8.Ling Yun.Analysis of attenuation by earth absorption.OGP,2001,36(1):1-8.
[4]凌云,高军,吴琳.时频空间域球面发散与吸收补偿.石油地球物理勘探,2005,40(2):176-182.Ling Yun,Gao Jun and Wu Lin.Compensation for spherical dispersion in time-frequency-space domain.OGP,2005,40(2):176-182.
[5]刘建华,胥颐,郝天珧.地震波衰减的物理机制研究.地球物理学进展,2004,19(1):1-6.Liu Jianhua,Xu Yi,Hao Tianyao.Study on physical mechanism of the seismic wave attentuation.Progress in Geophysics,2004,19(1):1-6.
[6]周发祥,宁鹏鹏,刘斌等.吸收衰减对地震分辨率的影响.石油地球物理勘探,2008,43(增刊2):84-87.Zhou Faxiang,Ning Pengpeng,Liu Bin et al.Influence of attenuation by absorption on seismic resolution.OGP,2008,43(S 2):84-87.
[7]钱绍瑚,高建华,谷永兴等.地层吸收衰减模型的制作及补偿方法的研究.石油地球物理勘探,1998,33(增刊1):18-24.
[8]Carcione J M.Seismic modeling in viscoelastic media.Geophysics,1993,58(1):110-120.
[9]Robertsson J O A,Blanch J O and Symes W W.Viscoelastic finite-diffence modeling.Geophysics,1994,59(9):1444-1456.
[10]Arntsen B,Nebel A G and Amundsen L.Visco-acoustic finite-difference modeling in the frequency domain.Journal of Seismic Exploration,1998,7(1):45-64.
[11]Saenger E H and Bohen T.Finite-difference modeling of viscoelastic and anisotropic wave propagation using the rotated staggered grid.Geophysics,2004,69(2):583-591.
[12]杜启振.各向异性黏弹性介质伪谱法波场模拟.物理学报,2004,53(12):4428-4434.Du Qizhen.Wavefield forward modeling with the pseudo-spectral method in viscoelastic and azimuthally anisotropic media.Acta Physica Sinica,2004,53(12):4428-4434.
[13]张智,刘财,邵志刚等.伪谱法在常Q黏弹介质地震波场模拟中的应用效果.地球物理学进展,2005,20(4):945-949.Zhang Zhi,Liu Cai,Shao Zhigang et al.The application of pseudo-spectral forward modeling of seismic wave field in constant Qviscoelastic medium.Progress in Geophysics,2005,20(4):945-949.
[14]宋常瑜,裴正林.井间地震黏弹性波场特征的数值模拟研究.石油物探,2006,45(5):508-513.Song Changyu and Pei Zhenglin.Numerical simulation of viscoelastic wavefield for crosshole seismic exploration.GPP,2006,45(5):508-513.
[15]牛滨华,孙春岩.黏弹介质与地震波传播.北京:地质出版社,2007.
[16]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,2005.
[17]成景旺,顾汉明,刘琳等.海上黏弹弹性介质FCT有限差分正演模拟.石油天然气学报,2011,33(12):83-87.Cheng Jingwang,Gu Hanming,Liu Lin et al.Flux correction transport(FCT)finite forward modeling for marine viscoelastic media.Journal of Oil and Gas Technology,2011,33(12):83-87.
[18]俞寿朋.高分辨率地震勘探.北京:石油工业出版社,1993.