复杂近地表波动方程波场延拓静校正
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摘要
当地形起伏剧烈、地表高程差较大时,采用传统的垂直静校正方法会使地震波场发生扭曲。基于单平方根算子的波动方程基准面静校正方法,将起伏地表的叠前数据通过波场外推到高于地形线的某一基准面上,在基准面与地形线之间填充一套新地层,填充层的速度选为接近于直达波;从地形线以下的某深度出发,在共炮点集中,根据菲涅尔原理以及检波点的空间位置,以检波点接收的地震数据为二次震源,通过上行波正向外推将检波点延拓到基准面上;再根据炮点、检波点互易原理,通过下行波反向外推将炮点延拓到基准面上。数值模拟结果证明,该方法正确有效,有利于后续的常规处理和叠前成像。图7参10
When topography and elevation differences vary between stations,conventional vertical static time shift will cause wavefield distortion.A novel approach of wave equation datum plane correction based on the single square-root operator is proposed: the seismic data on rugged acquisition topography is continued up to the datum plane above topography starting from some depth below near surface,by filling an additional layer between datum plane and topography with the velocity close to that of the first arrival wave.In common shot gathers,based on the Fresnel Principle and location of receivers,regarding the recorded data on real surface as a secondary emission the receivers are continued to the final datum plane by the forward propagation of upcoming wave.As a cascade step,all sources are continued up to the final datum plane in common receiver gathers,by the inverse propagation of down going wave based on the reciprocal principle of source and receiver.Numerical experiment results indicate that the method is correct and efficient,and is good for the subsequent seismic data processing.
When topography and elevation differences vary between stations,conventional vertical static time shift will cause wavefield distortion.A novel approach of wave equation datum plane correction based on the single square-root operator is proposed: the seismic data on rugged acquisition topography is continued up to the datum plane above topography starting from some depth below near surface,by filling an additional layer between datum plane and topography with the velocity close to that of the first arrival wave.In common shot gathers,based on the Fresnel Principle and location of receivers,regarding the recorded data on real surface as a secondary emission the receivers are continued to the final datum plane by the forward propagation of upcoming wave.As a cascade step,all sources are continued up to the final datum plane in common receiver gathers,by the inverse propagation of down going wave based on the reciprocal principle of source and receiver.Numerical experiment results indicate that the method is correct and efficient,and is good for the subsequent seismic data processing.
引文
[1]蔡春江,陈志刚,李学义.叠前偏移技术在准噶尔盆地逆冲断裂带地震资料处理中的应用[J].石油勘探与开发,2004,31(4):55-57(CAI Chun-jiang,CHENZhi-gang,LI Xue-yi,et al.Applicationof 2D pre-stack migration in sub-aerial reverse fracture zone inJunggar Basin,Northwest China[J].Petroleum Exploration andDevelopment,2004,31(4):55-57.)
[2]吴小洲,陈立康,邹才能,等.叠前深度偏移技术对速度变化平缓的复杂构造清晰成像[J].石油勘探与开发,2002,29(2):77-80.(WU Xiao-zhou,CHEN Li-kang,ZOU Cai-neng,et al.Applyingprestack depth migration to gental complex geologic structurei maginggained by using velocity model with gradient[J].PetroleumExploration and Development,2002,29(2):77-80.)
[3]张颖,乐金,阎世信,等.三维地震资料连片处理技术及应用效果[J].石油勘探与开发,2002,29(6):58-60.(ZHANG Ying,YUEJin,YUAN Shi-xin,et al.Multi-survey joint processing of 3-Dseismic data:techniques and applications[J].PetroleumExploration and Development,2002,29(6):58-60.)
[4]Berryhill J R.Wave equation datuming[J].Geophysics,1979,44(5):1329-1344.
[5]Berryhill J R.Wave equation datuming before stack[J].Geophy-sics,1984,49(11):2064-2067.
[6]Wiggins J W.Kirchhoff integral extrapolation and migration ofnonplanar data[J].Geophysics,1984,49(8):1239-1248.
[7]Shitivel man V,Canning A.Datum correction by wave equationextrapolation[J].Geophysics,1988,53(10):1311-1322.
[8]Yil maz O,Lucas D.Prestacklayer replacement[J].Geophysics,1986,51(8):1355-1369.
[9]Schneider W AJ,Philip L D,Paal E F.Wave equation velocityreplacement of the low-velocity layer for overthrust belt data[J].Geophysics,1995,60(17):573-580.
[10]Bevc D.Flooding the topography:Wave-equation datuming ofland data with rugged acquisition topography[J].Geophysics,1997,62(5):1558-1569.
[2]吴小洲,陈立康,邹才能,等.叠前深度偏移技术对速度变化平缓的复杂构造清晰成像[J].石油勘探与开发,2002,29(2):77-80.(WU Xiao-zhou,CHEN Li-kang,ZOU Cai-neng,et al.Applyingprestack depth migration to gental complex geologic structurei maginggained by using velocity model with gradient[J].PetroleumExploration and Development,2002,29(2):77-80.)
[3]张颖,乐金,阎世信,等.三维地震资料连片处理技术及应用效果[J].石油勘探与开发,2002,29(6):58-60.(ZHANG Ying,YUEJin,YUAN Shi-xin,et al.Multi-survey joint processing of 3-Dseismic data:techniques and applications[J].PetroleumExploration and Development,2002,29(6):58-60.)
[4]Berryhill J R.Wave equation datuming[J].Geophysics,1979,44(5):1329-1344.
[5]Berryhill J R.Wave equation datuming before stack[J].Geophy-sics,1984,49(11):2064-2067.
[6]Wiggins J W.Kirchhoff integral extrapolation and migration ofnonplanar data[J].Geophysics,1984,49(8):1239-1248.
[7]Shitivel man V,Canning A.Datum correction by wave equationextrapolation[J].Geophysics,1988,53(10):1311-1322.
[8]Yil maz O,Lucas D.Prestacklayer replacement[J].Geophysics,1986,51(8):1355-1369.
[9]Schneider W AJ,Philip L D,Paal E F.Wave equation velocityreplacement of the low-velocity layer for overthrust belt data[J].Geophysics,1995,60(17):573-580.
[10]Bevc D.Flooding the topography:Wave-equation datuming ofland data with rugged acquisition topography[J].Geophysics,1997,62(5):1558-1569.
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