三维叠前转换波克希霍夫时间偏移方法研究
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摘要
在地层含气时,转换波勘探可以获得更为丰富的地下信息。但由于转换波的射线路径不对称,因此转换波的叠前偏移比纵波复杂。在VTI介质中,三维叠前转换波克希霍夫时间偏移的旅行时受偏移孔径、速度模型和双程垂向旅行时等多种因素的影响,为此,对转换波旅行时的计算方法和偏移算法进行了讨论。转换波旅行时由激发点到成像点的纵波旅行时和成像点到接收点的转换波旅行时两部分构成,通过建立旅行时表来提高偏移计算效率,保证旅行时精度。同时,讨论了基于VTI介质的三维转换波叠前时间偏移近似算法,利用理论模型验证了叠前时间偏移方法的正确性。对西部某油田实际转换波地震资料进行三维叠前时间偏移的结果与井资料较为吻合,含气地层的成像优于纵波。
Converted wave exploration can obtain abundant information in gas-bearing horizon.The pre-stack migration of converted-wave is more complex than that of P-wave because the ray paths of the converted-wave are asymmetry.In VTI media,the travel time of 3-D pre-stack Kirchhoff time migration for converted-wave is af- fected by many factors,including migration aperture,velocity model,and two-way vertical travel time.Aiming at this problem, we discussed the calculation method and migration algorithm of converted-wave travel time.The travel time includes the P-wave travel time from the source to imaging points and the converted- wave travel time from imaging points to receivers.The travel-time form is established to improve the migration computation efficiency and guarantee the accuracy of travel time.In addition,we also dis- cussed the algorithm for 3-D pre-stack time migration of converted- wave in VTI media.The validity of pre-stack time migration meth- od is verified by a theoretical model.The 3-D pre-stack migration result of one actual converted-wave data from a certain oilfield in west area matches its logging data very well and the imaging effect in gas-bearing horizon is better than that of P-wave.
Converted wave exploration can obtain abundant information in gas-bearing horizon.The pre-stack migration of converted-wave is more complex than that of P-wave because the ray paths of the converted-wave are asymmetry.In VTI media,the travel time of 3-D pre-stack Kirchhoff time migration for converted-wave is af- fected by many factors,including migration aperture,velocity model,and two-way vertical travel time.Aiming at this problem, we discussed the calculation method and migration algorithm of converted-wave travel time.The travel time includes the P-wave travel time from the source to imaging points and the converted- wave travel time from imaging points to receivers.The travel-time form is established to improve the migration computation efficiency and guarantee the accuracy of travel time.In addition,we also dis- cussed the algorithm for 3-D pre-stack time migration of converted- wave in VTI media.The validity of pre-stack time migration meth- od is verified by a theoretical model.The 3-D pre-stack migration result of one actual converted-wave data from a certain oilfield in west area matches its logging data very well and the imaging effect in gas-bearing horizon is better than that of P-wave.
引文
1 Harrison M P,Stewart R R.Poststack migration of P-SV seismic data[J].Geophysics,1993,58(8): 1127～1135
2王磊，李建荣，王赟．多分量转换波地震勘探技术[J]．油气地质与采收率，2002，9(6)：1～4
3 Zhe J P,Greenhalgh S A.Prestack multicomponent migration[J].Geophysics,1997,62(2):598～613
4李录明．P-P波及P-SV波叠前深度偏移速度模型建立方法[J]．地球物理学报，1998，41(增刊)：305～317
5 Li X Y,Dai H C,Yuan J.Converted wave imaging in inhomogeneous,anisotropic media:prestack migration [J].Expanded Abstract of EAGE 63~(rd)Annual Confer- ence,2001,114～117
6 Sun C W,Martinez R D.3D Kirchhoff PS-wave pre- stack time migration for V(z)and VTI media[J].Ex- panded Abstracts of 73~(rd)Annual Internat SEG Mtg, 2003,957～960
7牟永光．地震勘探资料数字处理方法[M]．北京：石油工业出版社，1980．180～183
8 Li X Y,Yuan J.Converted wave travel time equation in layered anisotropic media:an overview[R].Edin- burgh:EAP Annual Research Report,2001,3～32
9张艳丽，刘洋．转换波叠前时间偏移方法综述[J]．地球物理学进展，2005，20(4)：1134～1139
10寻浩，董敏煜，牟永光．横向各向同性介质中的AVO [J]．石油地球物理勘探，1997，32(1)：46～56
11宁书年，吴志勤，王赟，等．叠前Kirchhoff积分偏移法纵横波振幅比剖面的提取与应用[J]．中国矿业大学学报，2004，33(5)：495～498
2王磊，李建荣，王赟．多分量转换波地震勘探技术[J]．油气地质与采收率，2002，9(6)：1～4
3 Zhe J P,Greenhalgh S A.Prestack multicomponent migration[J].Geophysics,1997,62(2):598～613
4李录明．P-P波及P-SV波叠前深度偏移速度模型建立方法[J]．地球物理学报，1998，41(增刊)：305～317
5 Li X Y,Dai H C,Yuan J.Converted wave imaging in inhomogeneous,anisotropic media:prestack migration [J].Expanded Abstract of EAGE 63~(rd)Annual Confer- ence,2001,114～117
6 Sun C W,Martinez R D.3D Kirchhoff PS-wave pre- stack time migration for V(z)and VTI media[J].Ex- panded Abstracts of 73~(rd)Annual Internat SEG Mtg, 2003,957～960
7牟永光．地震勘探资料数字处理方法[M]．北京：石油工业出版社，1980．180～183
8 Li X Y,Yuan J.Converted wave travel time equation in layered anisotropic media:an overview[R].Edin- burgh:EAP Annual Research Report,2001,3～32
9张艳丽，刘洋．转换波叠前时间偏移方法综述[J]．地球物理学进展，2005，20(4)：1134～1139
10寻浩，董敏煜，牟永光．横向各向同性介质中的AVO [J]．石油地球物理勘探，1997，32(1)：46～56
11宁书年，吴志勤，王赟，等．叠前Kirchhoff积分偏移法纵横波振幅比剖面的提取与应用[J]．中国矿业大学学报，2004，33(5)：495～498
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