双聚焦法近地表静校正
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摘要
面对着日益复杂的地表采集条件,静校正已经成为地震资料处理中急需解决的关键技术难题。以往通常采用时移静校正去消除复杂近地表的影响,但时移静校正受地表一致性条件的限制和对速度的依赖,复杂近地表条件下,时移法静校正很难满足高精度资料处理的要求。本文引进了近年才发展起来的一种新的静校正方法—双聚焦法近地表静校正,该方法的理论基础是共聚焦点技术,它完全是靠数据驱动的,用聚焦算子来描述近地表的影响。根据等时原理,我们对这些算子进行了更新。使用这些更新过的算子,把起伏地表校正到了风化层下的一水平面,进而消除了起伏地表和复杂地表的影响。
在进行双聚焦近地表静校正过程中,获得正确的聚焦算子是非常关键的,而这就要求对地表结构有充分的认识。论文利用了CFP技术的中间结果—CFP道集和DTS道集,并采用与摄动法相结合的约束参数反演方法对起伏地表的近地表结构进行了分析。正确的聚焦算子的求取主要是以等时原理作为判别准则、差异时移分析作为依据,对算子进行迭代更新,以得到正确的聚焦算子的旅行时。在算子更新前,我们对错误的聚焦算子对CFP道集合成以及DTS面板形态产生的影响做了具体的分析,进而可知算子更新是非常必要的。但算子振幅在起伏地表情况下是需要我们去考虑的,本文采用一种新的近似算子振幅的计算方法获得了满足要求的算子振幅,提高了聚焦算子和CFP道集的分辨率,进而提高了DTS时差拾取的精度。另外,论文还利用稳相原理获得了高质量的CFP道集。
论文中分别给出了上述方法的介绍,模型试算证明了上述方法的有效性。理论模型和实际资料的试处理表明,双聚焦法近地表静校正的处理效果要优于常规的时移静校正,这验证了该方法的正确性和可行性,并说明其具有良好的应用前景。
Facing creasingly complex near-surface acquisition conditions, static has become a vital technique problem to settle in seismic data process. It was used to utilize time shift static to eliminate complex near-surface effects, but this method is restricted by near-surface consistence condition and greatly depends on velocity. Time shift static hardly meet the request of high precision process when counter with complex surface acquisition conditions. This paper introduce a kind of new static method developed recently—near surface static based on double focus method, its theory base is common focus point technology, it depends completely on data-driven, makes use of synthesis operators to describe near-surface effects. Based on equal travel time principle, we can update these operators. Using the updated operators, we can correct rugged surface to a sub-weather plane surface, thus the effects of rugged surface and complex near-surface are eliminated.
In the progress of using the double focus method to realize static, the key technique is attain correct synthesis operator, which desired sufficient acknowledgment with the near-surface configuration. The paper use middle result of CFP technology—CFP gather and DTS gather, and analyzes near-surface configuration by means of parameter constraint iterative inversion integrated with perturbation methods. Equal travel time principle and DTS analysis are the basis of correct synthesis operator calculation. Before updating the operators, we analyze the effects of wrong synthesis operator on synthesized CFP gather and shape of DTS, thus we can see the necessity of the updating operator. And we also have to consider operator’s amplitude, the paper introduces an new approximative calculation of operator amplitude to get desired operator’s amplitude, which is also improves differentiate of synthesis operator and CFP gather, thus improves collection precision of DTS. In addition, the paper also use steady phase principle to obtain high quality CFP gather.
In this paper we give the introduction of above methods, the model tests showed their validity. The processing results of model and real data proved that near-surface static based on double focus method is prior to the conventional time shift static. And the prospect of this technique is very good.
在进行双聚焦近地表静校正过程中,获得正确的聚焦算子是非常关键的,而这就要求对地表结构有充分的认识。论文利用了CFP技术的中间结果—CFP道集和DTS道集,并采用与摄动法相结合的约束参数反演方法对起伏地表的近地表结构进行了分析。正确的聚焦算子的求取主要是以等时原理作为判别准则、差异时移分析作为依据,对算子进行迭代更新,以得到正确的聚焦算子的旅行时。在算子更新前,我们对错误的聚焦算子对CFP道集合成以及DTS面板形态产生的影响做了具体的分析,进而可知算子更新是非常必要的。但算子振幅在起伏地表情况下是需要我们去考虑的,本文采用一种新的近似算子振幅的计算方法获得了满足要求的算子振幅,提高了聚焦算子和CFP道集的分辨率,进而提高了DTS时差拾取的精度。另外,论文还利用稳相原理获得了高质量的CFP道集。
论文中分别给出了上述方法的介绍,模型试算证明了上述方法的有效性。理论模型和实际资料的试处理表明,双聚焦法近地表静校正的处理效果要优于常规的时移静校正,这验证了该方法的正确性和可行性,并说明其具有良好的应用前景。
Facing creasingly complex near-surface acquisition conditions, static has become a vital technique problem to settle in seismic data process. It was used to utilize time shift static to eliminate complex near-surface effects, but this method is restricted by near-surface consistence condition and greatly depends on velocity. Time shift static hardly meet the request of high precision process when counter with complex surface acquisition conditions. This paper introduce a kind of new static method developed recently—near surface static based on double focus method, its theory base is common focus point technology, it depends completely on data-driven, makes use of synthesis operators to describe near-surface effects. Based on equal travel time principle, we can update these operators. Using the updated operators, we can correct rugged surface to a sub-weather plane surface, thus the effects of rugged surface and complex near-surface are eliminated.
In the progress of using the double focus method to realize static, the key technique is attain correct synthesis operator, which desired sufficient acknowledgment with the near-surface configuration. The paper use middle result of CFP technology—CFP gather and DTS gather, and analyzes near-surface configuration by means of parameter constraint iterative inversion integrated with perturbation methods. Equal travel time principle and DTS analysis are the basis of correct synthesis operator calculation. Before updating the operators, we analyze the effects of wrong synthesis operator on synthesized CFP gather and shape of DTS, thus we can see the necessity of the updating operator. And we also have to consider operator’s amplitude, the paper introduces an new approximative calculation of operator amplitude to get desired operator’s amplitude, which is also improves differentiate of synthesis operator and CFP gather, thus improves collection precision of DTS. In addition, the paper also use steady phase principle to obtain high quality CFP gather.
In this paper we give the introduction of above methods, the model tests showed their validity. The processing results of model and real data proved that near-surface static based on double focus method is prior to the conventional time shift static. And the prospect of this technique is very good.
引文
[1] Berryhill J. R.. Wave equation datuming. Geophysics, 1979;44 (8):1329–1344.
[2] Berryhill J. R.. Wave equation datuming before stack. Geophysics, 1984; 49(11): 2064–2067.
[3] Reshef M.Depth migration from irregular surfaces with depth extrapolation methods . Geophysics, 1991, 56(1),119-122.
[4] Bevc D.. Flooding the topography: Wave equation datuming of land data with rugged acquisition topography. Geophysics, 1997; 62(5), 1558~1569.
[5] Bevc D.. Imaging under rugged topography and complex velocity structure. [Ph.D. thesis], Stanford University, The Ameraica: 1995.
[6] Kelamis, P. G. et al. Cfp-based redatuming: Synthetic and field data examples: 70th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 2000: 509–512.
[7] Berkhout A.J.Pushing the limits of seismic imaging, PartⅠ: Prestack migration in terms of double dynamic focusing Geophysics . 1997;62:937-953
[8] Berkhout A.J.Pushing the limits of seismic imaging, PartⅡ:Intergration of prestack migration ,velocity estimation, and AVO analysis. Geophysics, 1997;62, 954-969.
[9] Berkhout A.J.Seismic Resolution.Geophys.1984;Press,CharpterⅥ:177-192–Seismic migration: Imaging of acoustic energy by wavefield extrapolation, third edition. Elsev- ier Science Publ.Co. Inc.1985;ChapterⅥ:185-244—Areal shot record technology. J.Seis.Expl.1992.
[10] E.J.van Veldhuizen. Operator amplitude determination for CFP redatuming through a complex near surface. PhD thesis, Delft University of Technology, 2002
[11] J.F.B.Bolte and D.J.Verschuur. Aspects of focusing operator updating.1998 SEG Expanded Abstracts.
[12] Thorbecke J W.Common Focus Point Technology (Ph.D. Thesis). Delft University of Technology, 1997.
[13] Vinje V.Travel time and amplitude estimation using wave-front construction. Geophysics, 1993; 58: 1157-1166.
[14] Vidale J..Finite-difference calculation in three dimensions. Geophysics, 1990; 55: 521-526.
[15]刘玉莲.基于有限差分走时计算的Kichhoff型保幅叠前深度偏移:[硕士学位论文],石油大学(华东),东营:2004.
[16]马光凯.基于CFP技术的起伏地表基准面重建和近地表结构研究:[硕士学位论文],石油大学(华东),东营:2006.
[17] Hindriks COH, et al. Model independent, true amplitude redatuming for complex near surface effects. 72nd Annual Internat. Mtg., Soc.Expl. Geophys., Expanded Abstracts, 2002:967-974.
[18] Hindriks, C. and Duijndam,A..Handling near surface effects in imaging by using com- mon focal point technology: 69th Ann. Internat. Mtg., Soc. Expl, Geophys, Expanded Abstracts, 1999:575–578.
[19] Bolte J, Verschuur D.. Velocity independent CFP redatuming: strategy for subsalt imaging .71nd Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 2001:1201-1204.
[20] Bolte J F B, Estimation of focusing operators using the common focal point method [D]. The Delft: Delft University of Technology, 2003.
[21] Cox M, Static corrections for seismic reflection surveys[M], USA Tulsa: Society of Exploration Geophysicsts, 1999,531.
[22]李振春等.波动方程法共成像点道集偏移速度建模.地球物理学报,2003;46:86-93.
[23]李振春.多道集偏移速度建模方法研究:[博士论文],同济大学,上海:2002.
[24]辛可锋.共聚焦点成像速度建模方法的应用研究:[博士论文],同济大学,上海:2003.
[25]马在田.计算地球物理学概论.上海:同济大学出版社,1997年:50-67.
[26] Berkhout A.J.and Rietveld W.E.A. Determination of macromodles for prestack migration.PartⅠ:Estimation of macrovelocities.64th Ann.Internat, Mtg.Soc. Expl, Geophys, Expanted Abstracts, 1994:1330-1333.
[27] Hegge R.F. et al. Using focusing operators to estimate velocity models: 68th Annual Internat. Mtg., Soc.Expl. Geophys., Expanded Abstracts, 1998.
[28] Ken Larner, Gabriel Perez, Ed Jenner, Trino Salinas, The quality of the surface-consistency assumption in residual-statics estimation[A]. In: Soc. Expl. Geophys. 66th Ann. Internat. Mtg Expanded Abstracts[C], 1996: 1646~1649.
[29] Beasley C, Lynn W. The zero velocity layer: Migration from irregular surface. Geophysics, 1992; 57(11), 1435–1443.
[30] Wiggins J. W.. Kirchhoff integral extrapolation and migration of nonplanar data. Geophysics, 1984; 49(8), 1239–1248.
[31] Yilmaz O., Lucas D.. Prestack layer replacement. Geophysics, 1986; 51(7), 1355–1369.
[32] Shtivelman V., Canning A.. Datum correction by wave equation extrapolation. Geophysics, 1988; 53(10), 1311~1322.
[33] Langan R.T.Tracing of rays through heterogeneous media : An accurate and efficient procedure.Geophysics , 1985;50:1456-1465.
[34] Schneider W. A. et al. Wave equation velocity replacement of the low-velocity layer for overthrust belt data. Geophysics, 1995; 60(2), 573~580.
[35] Vidale J.Finite-difference calculation of travel times.Bulletin of the Seismiclogical Society of America, 1988; Vol.78, No.6: 2062-2076.
[36] Podvin P and Lecomte I.Finite difference computation of travel times in very contrasted velocity models: A massively parallel approach and its associated tools. Geophysical Journal International, 1991; 105: 271-284.
[37]李振春,张凯,张建磊等.共聚焦点偏移成像方法研究[J].石油物探, 2003, 42(1), 16~21.
[38]王锡文.利用共聚焦点方法消除复杂的近地表效应[J].勘探地球物理进展, 2004,27(4):260~265.
[39]王成祥,赵波,张关泉,等.地下复杂介质地震处理中的CFP技术[J].地球物理学进展, 2003, 18(1):30~34.
[40]俞国柱,姚姚等.共聚焦点(CFP)成像技术述评[J].石油地球物理勘探, 2002, 37(4): 412~422.
[41]娄晓东,曹谊,赵青.地震处理新方法—共聚焦点技术[J].勘探地球物理进展, 2002, 25(5): 7~17.
[42]李振春,张建磊,王延光等.基于共聚焦点道集的叠前深度偏移及其应用[J].石油大学学报, 2003, 27(4):27~31.
[43]吕斌.基于CFP技术的保幅处理与CFP-AVP分析方法:[硕士学位论文],石油大学(华东),东营:2006.
[44]安琪.基于CFP技术的偏移速度建模方法:[硕士学位论文],中国石油大学(华东),东营:2007.
[45]徐秀刚.基于波动理论的CFP偏移与CFP-AVP分析:[硕士学位论文],中国石油大学(华东),东营:2007.
[46]王红落等.波动方程基准面延拓研究进展.地球物理学进展,2004;19(2):230-234.
[47]李振春.地震成像理论与方法.东营:石油大学研究生院,2004:42-47,173-177.
[48]李录明,罗省贤.波场延拓表层模型校正.石油地球物理勘探,2001;36(5):572-583.
[49]李振春,张军华.地震数据处理方法.东营:石油大学出版社,2004:146-180.
[50]陆基孟.地震勘探原理.东营:石油大学出版社,1993:189-210.
[2] Berryhill J. R.. Wave equation datuming before stack. Geophysics, 1984; 49(11): 2064–2067.
[3] Reshef M.Depth migration from irregular surfaces with depth extrapolation methods . Geophysics, 1991, 56(1),119-122.
[4] Bevc D.. Flooding the topography: Wave equation datuming of land data with rugged acquisition topography. Geophysics, 1997; 62(5), 1558~1569.
[5] Bevc D.. Imaging under rugged topography and complex velocity structure. [Ph.D. thesis], Stanford University, The Ameraica: 1995.
[6] Kelamis, P. G. et al. Cfp-based redatuming: Synthetic and field data examples: 70th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 2000: 509–512.
[7] Berkhout A.J.Pushing the limits of seismic imaging, PartⅠ: Prestack migration in terms of double dynamic focusing Geophysics . 1997;62:937-953
[8] Berkhout A.J.Pushing the limits of seismic imaging, PartⅡ:Intergration of prestack migration ,velocity estimation, and AVO analysis. Geophysics, 1997;62, 954-969.
[9] Berkhout A.J.Seismic Resolution.Geophys.1984;Press,CharpterⅥ:177-192–Seismic migration: Imaging of acoustic energy by wavefield extrapolation, third edition. Elsev- ier Science Publ.Co. Inc.1985;ChapterⅥ:185-244—Areal shot record technology. J.Seis.Expl.1992.
[10] E.J.van Veldhuizen. Operator amplitude determination for CFP redatuming through a complex near surface. PhD thesis, Delft University of Technology, 2002
[11] J.F.B.Bolte and D.J.Verschuur. Aspects of focusing operator updating.1998 SEG Expanded Abstracts.
[12] Thorbecke J W.Common Focus Point Technology (Ph.D. Thesis). Delft University of Technology, 1997.
[13] Vinje V.Travel time and amplitude estimation using wave-front construction. Geophysics, 1993; 58: 1157-1166.
[14] Vidale J..Finite-difference calculation in three dimensions. Geophysics, 1990; 55: 521-526.
[15]刘玉莲.基于有限差分走时计算的Kichhoff型保幅叠前深度偏移:[硕士学位论文],石油大学(华东),东营:2004.
[16]马光凯.基于CFP技术的起伏地表基准面重建和近地表结构研究:[硕士学位论文],石油大学(华东),东营:2006.
[17] Hindriks COH, et al. Model independent, true amplitude redatuming for complex near surface effects. 72nd Annual Internat. Mtg., Soc.Expl. Geophys., Expanded Abstracts, 2002:967-974.
[18] Hindriks, C. and Duijndam,A..Handling near surface effects in imaging by using com- mon focal point technology: 69th Ann. Internat. Mtg., Soc. Expl, Geophys, Expanded Abstracts, 1999:575–578.
[19] Bolte J, Verschuur D.. Velocity independent CFP redatuming: strategy for subsalt imaging .71nd Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 2001:1201-1204.
[20] Bolte J F B, Estimation of focusing operators using the common focal point method [D]. The Delft: Delft University of Technology, 2003.
[21] Cox M, Static corrections for seismic reflection surveys[M], USA Tulsa: Society of Exploration Geophysicsts, 1999,531.
[22]李振春等.波动方程法共成像点道集偏移速度建模.地球物理学报,2003;46:86-93.
[23]李振春.多道集偏移速度建模方法研究:[博士论文],同济大学,上海:2002.
[24]辛可锋.共聚焦点成像速度建模方法的应用研究:[博士论文],同济大学,上海:2003.
[25]马在田.计算地球物理学概论.上海:同济大学出版社,1997年:50-67.
[26] Berkhout A.J.and Rietveld W.E.A. Determination of macromodles for prestack migration.PartⅠ:Estimation of macrovelocities.64th Ann.Internat, Mtg.Soc. Expl, Geophys, Expanted Abstracts, 1994:1330-1333.
[27] Hegge R.F. et al. Using focusing operators to estimate velocity models: 68th Annual Internat. Mtg., Soc.Expl. Geophys., Expanded Abstracts, 1998.
[28] Ken Larner, Gabriel Perez, Ed Jenner, Trino Salinas, The quality of the surface-consistency assumption in residual-statics estimation[A]. In: Soc. Expl. Geophys. 66th Ann. Internat. Mtg Expanded Abstracts[C], 1996: 1646~1649.
[29] Beasley C, Lynn W. The zero velocity layer: Migration from irregular surface. Geophysics, 1992; 57(11), 1435–1443.
[30] Wiggins J. W.. Kirchhoff integral extrapolation and migration of nonplanar data. Geophysics, 1984; 49(8), 1239–1248.
[31] Yilmaz O., Lucas D.. Prestack layer replacement. Geophysics, 1986; 51(7), 1355–1369.
[32] Shtivelman V., Canning A.. Datum correction by wave equation extrapolation. Geophysics, 1988; 53(10), 1311~1322.
[33] Langan R.T.Tracing of rays through heterogeneous media : An accurate and efficient procedure.Geophysics , 1985;50:1456-1465.
[34] Schneider W. A. et al. Wave equation velocity replacement of the low-velocity layer for overthrust belt data. Geophysics, 1995; 60(2), 573~580.
[35] Vidale J.Finite-difference calculation of travel times.Bulletin of the Seismiclogical Society of America, 1988; Vol.78, No.6: 2062-2076.
[36] Podvin P and Lecomte I.Finite difference computation of travel times in very contrasted velocity models: A massively parallel approach and its associated tools. Geophysical Journal International, 1991; 105: 271-284.
[37]李振春,张凯,张建磊等.共聚焦点偏移成像方法研究[J].石油物探, 2003, 42(1), 16~21.
[38]王锡文.利用共聚焦点方法消除复杂的近地表效应[J].勘探地球物理进展, 2004,27(4):260~265.
[39]王成祥,赵波,张关泉,等.地下复杂介质地震处理中的CFP技术[J].地球物理学进展, 2003, 18(1):30~34.
[40]俞国柱,姚姚等.共聚焦点(CFP)成像技术述评[J].石油地球物理勘探, 2002, 37(4): 412~422.
[41]娄晓东,曹谊,赵青.地震处理新方法—共聚焦点技术[J].勘探地球物理进展, 2002, 25(5): 7~17.
[42]李振春,张建磊,王延光等.基于共聚焦点道集的叠前深度偏移及其应用[J].石油大学学报, 2003, 27(4):27~31.
[43]吕斌.基于CFP技术的保幅处理与CFP-AVP分析方法:[硕士学位论文],石油大学(华东),东营:2006.
[44]安琪.基于CFP技术的偏移速度建模方法:[硕士学位论文],中国石油大学(华东),东营:2007.
[45]徐秀刚.基于波动理论的CFP偏移与CFP-AVP分析:[硕士学位论文],中国石油大学(华东),东营:2007.
[46]王红落等.波动方程基准面延拓研究进展.地球物理学进展,2004;19(2):230-234.
[47]李振春.地震成像理论与方法.东营:石油大学研究生院,2004:42-47,173-177.
[48]李录明,罗省贤.波场延拓表层模型校正.石油地球物理勘探,2001;36(5):572-583.
[49]李振春,张军华.地震数据处理方法.东营:石油大学出版社,2004:146-180.
[50]陆基孟.地震勘探原理.东营:石油大学出版社,1993:189-210.