TTI各向异性叠前深度偏移在高陡构造区应用——以DB三维区为例
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摘要
由于DB三维区古近系盐上浅层高陡,盐下目的层逆冲断片发育,导致地震资料品质差:信噪比低,成像不理想。无论是时间域处理还是各向同性叠前深度偏移处理,均难以得到好的成像,不能满足构造精细解释需要,限制了该区天然气勘探。为了提高地震资料品质,这里针对DB高陡构造低信噪比资料,除了处理解释一体化提高高速砾岩体速度建模精度外,重点开展了倾斜介质——TTI各向异性参数研究,获得了参数预测的有效方法。通过各向异性模型与速度模型的迭代,使得叠前深度偏移的速度模型更加合理,明显提高了地震资料成像质量。
Many gas and oil reservoirs have been discovered in DB 3D seismic district which is located in the north of Kuqa depression in the Tarim basin.The wave field is complicated caused by the precipitous upper layer and the multiple fragments under the salt.And the velocity's anisotropy problem is so serious that the quality of the seismic data is bad:low signal-to-noise ratio,unable to image well.Neither processing in time area nor prestack depth migration processing in isotropy media is good enough to image.And the failure in exact interpretation of seismic data limits the exploration of gas in the area.In order to improve the quality of the seismic data,our work in the DB precipitous structure area,which is low signal-to-noise ratio,emphasis on studying in the anisotropy parameters in TTI media to propose a valid method for estimating parameters,along with improving the accuracy of velocity modeling by combination of both processing and interpretation of the high-speed conglomerate.By iteration of anisotropy and velocity model,we have a more acceptable prestack depth migration velocity model with which we improve in imaging and provide assurance for gas exploration in the area.
Many gas and oil reservoirs have been discovered in DB 3D seismic district which is located in the north of Kuqa depression in the Tarim basin.The wave field is complicated caused by the precipitous upper layer and the multiple fragments under the salt.And the velocity's anisotropy problem is so serious that the quality of the seismic data is bad:low signal-to-noise ratio,unable to image well.Neither processing in time area nor prestack depth migration processing in isotropy media is good enough to image.And the failure in exact interpretation of seismic data limits the exploration of gas in the area.In order to improve the quality of the seismic data,our work in the DB precipitous structure area,which is low signal-to-noise ratio,emphasis on studying in the anisotropy parameters in TTI media to propose a valid method for estimating parameters,along with improving the accuracy of velocity modeling by combination of both processing and interpretation of the high-speed conglomerate.By iteration of anisotropy and velocity model,we have a more acceptable prestack depth migration velocity model with which we improve in imaging and provide assurance for gas exploration in the area.
引文
[1]渥!伊尔马滋.地震资料分析[M].北京:石油工业出版社,2006.
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[3]φRJAN PEDERSEN,BJRN URSIN,ALEXEY STOVAS.Wide-angle phase-slowness approximations in VTI media[J].Geophysics,2007(72):177.
[4]JRG SCHLEICHER,RAFAEL ALEIXO.Time and depth remigration in elliptically anisotropic media using image-wave propagation[J].Geophysics,2007(72):1.
[5]BJφRN URSIN,ALEXEY STOVAS.Generalized Dix equations for a layered transversely isotropic medium[J].Geophysics,2005(70):77.
[6]GUOJIAN SHAN,IONDO BIONDI.Plane-wave migration in tilted coordinates[J].Geophysics,2008(70):185.
[7]HUUB DOUMA,MIRKO VAN DER BAAN.Rational interpolation of qP-traveltimes for semblance-based anisotropy estimation in layered VTI media[J].Geophysics,2008(73):53.
[8]薛冈,王良书,胡中平.大炮检距地震资料动校正方法比较[J].石油地球物理勘探,2003,38(2):151.
[9]凌云,郭向宇,孙祥娥,等,地震勘探中的各向异性影响问题研究[J].石油地球物理勘探,2010,45(4):606.
[2]THOMSEN,L.Weak elastic anisotropy[J].Geophysics,1986(51):1951.
[3]φRJAN PEDERSEN,BJRN URSIN,ALEXEY STOVAS.Wide-angle phase-slowness approximations in VTI media[J].Geophysics,2007(72):177.
[4]JRG SCHLEICHER,RAFAEL ALEIXO.Time and depth remigration in elliptically anisotropic media using image-wave propagation[J].Geophysics,2007(72):1.
[5]BJφRN URSIN,ALEXEY STOVAS.Generalized Dix equations for a layered transversely isotropic medium[J].Geophysics,2005(70):77.
[6]GUOJIAN SHAN,IONDO BIONDI.Plane-wave migration in tilted coordinates[J].Geophysics,2008(70):185.
[7]HUUB DOUMA,MIRKO VAN DER BAAN.Rational interpolation of qP-traveltimes for semblance-based anisotropy estimation in layered VTI media[J].Geophysics,2008(73):53.
[8]薛冈,王良书,胡中平.大炮检距地震资料动校正方法比较[J].石油地球物理勘探,2003,38(2):151.
[9]凌云,郭向宇,孙祥娥,等,地震勘探中的各向异性影响问题研究[J].石油地球物理勘探,2010,45(4):606.
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