面向地质目标的地震采集设计优化方法
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摘要
本文简要回顾了济阳拗陷三维地震采集观测系统的发展历程,从济阳拗陷的地震地质条件出发,进行了面向地质目标的地震采集优化设计方法研究,并获得以下认识:①薄层模型单炮正演模拟表明,只有较高的地震子波主频才能分辨薄层,且随着炮检距增大,将发生薄层干涉现象,并导致地震子波主频降低。因此一定要充分利用中、近炮检距信息研究薄层,并进行分炮检距处理。②通过对缓坡带、洼陷带、中央断裂背斜构造带、潜山披覆构造、陡坡带等地质模型的二维、三维正演模拟认识到:无论激发点位置如何,地下复杂界面反射的有效接收范围都集中在反射段正上方;对于复杂构造,宜采用小炮距、小接收线距、适中的排列片长度和宽度,以确保观测波场的连续性。③面向地质目标的地震采集设计优化的关键技术是建立符合实际的三维地震地质模型,并针对目的层段进行正演模拟,分析不同观测方案的CRP覆盖次数分布,以优选观测系统。CG油田三维地震采集优化设计实例表明,文中方法对具有复杂构造的陆相断陷盆地的地震采集优化设计具有借鉴意义。
The paper briefly reviewed the development history of 3-D seismic acquisition geometry in Jiyang depression, and carried out the study on the optimum design method of geologic target-oriented seismic acquisition by starting from the seismic and geologic conditions of Jiyang depression, which obtained following knowledge:①the single-shot forward simulation of thin-layer model showed the phenomenon of thin-layer interference will be taken place along with increasing the offset, leading to decrease the dominant frequency of seismic wavelet. So, it should fully use mid and near offsets data to study thin layer and carry out offset-divided processing; ②it is known by 2-D and 3-D forward simulation of geologic models such as gentle slope zone, depression zone, central faulted anticline structural zone, buried hill drape structure and steep slope zone that the effective receiving range of reflections from underground complex interface is concentrated into the right upper position of reflections no matter where the shooting points are. It is convenient to use short shot interval and receiving line interval as well as adequate length and width of spread patch for complex structure; ③the key technique of optimum design method of geologic target-oriented seismic acquisition is to build up 3-D seismic and geologic model consistent with practice, carry out forward simulation faced with objective horizon and analyze the distribution of CRP folds in different surveying scheme in order to optimize the geometry.The case of 3-D optimum seismic acquisition design in CG oilfield showed the method in the paper has referential meaning for optimum seismic acquisition design in continental faulted basin having complex structure.
The paper briefly reviewed the development history of 3-D seismic acquisition geometry in Jiyang depression, and carried out the study on the optimum design method of geologic target-oriented seismic acquisition by starting from the seismic and geologic conditions of Jiyang depression, which obtained following knowledge:①the single-shot forward simulation of thin-layer model showed the phenomenon of thin-layer interference will be taken place along with increasing the offset, leading to decrease the dominant frequency of seismic wavelet. So, it should fully use mid and near offsets data to study thin layer and carry out offset-divided processing; ②it is known by 2-D and 3-D forward simulation of geologic models such as gentle slope zone, depression zone, central faulted anticline structural zone, buried hill drape structure and steep slope zone that the effective receiving range of reflections from underground complex interface is concentrated into the right upper position of reflections no matter where the shooting points are. It is convenient to use short shot interval and receiving line interval as well as adequate length and width of spread patch for complex structure; ③the key technique of optimum design method of geologic target-oriented seismic acquisition is to build up 3-D seismic and geologic model consistent with practice, carry out forward simulation faced with objective horizon and analyze the distribution of CRP folds in different surveying scheme in order to optimize the geometry.The case of 3-D optimum seismic acquisition design in CG oilfield showed the method in the paper has referential meaning for optimum seismic acquisition design in continental faulted basin having complex structure.
引文
[1]Berkhout A J.Design criteria for3-D seismic acquisi-tion.Seismic Explor,1998,7(1):65~72
[2]Slawson S E.Model-based3-D seismic acquisition de-sign.Expanded Abstracts of64th SEG Mtg,1994
[3]Brink M.Effects of seismic aquisition geometry on seismic processing:analysis of the DMO techniques.Geophys Lith Predic,1996
[4]Beasley C J.I maging properties of modern3-D seismic acquisition systems.Explor Geophys,1997,28(1,2):192~194
[5]Norm Cooper.A world of reality-Designing land3D programs for signal,noise and prestack migration.The Leading Edge,2004,23(10):1007~1014,(12):1230~1235
[6]熊翥.我国物探技术的进步及展望.石油地球物理勘探,2003,38(4):447~459
[7]沈财余.东营凹陷三维地震采集评述.油气地质与采收率,2004,11(1):42~44
[8]韩文功,沈财余.陆相断陷盆地复杂地质模型建立与正演模拟.石油地球物理勘探,2006,41(4):396~401
[9]陆基孟.地震勘探原理(上册).山东东营:石油大学出版社,1993
[2]Slawson S E.Model-based3-D seismic acquisition de-sign.Expanded Abstracts of64th SEG Mtg,1994
[3]Brink M.Effects of seismic aquisition geometry on seismic processing:analysis of the DMO techniques.Geophys Lith Predic,1996
[4]Beasley C J.I maging properties of modern3-D seismic acquisition systems.Explor Geophys,1997,28(1,2):192~194
[5]Norm Cooper.A world of reality-Designing land3D programs for signal,noise and prestack migration.The Leading Edge,2004,23(10):1007~1014,(12):1230~1235
[6]熊翥.我国物探技术的进步及展望.石油地球物理勘探,2003,38(4):447~459
[7]沈财余.东营凹陷三维地震采集评述.油气地质与采收率,2004,11(1):42~44
[8]韩文功,沈财余.陆相断陷盆地复杂地质模型建立与正演模拟.石油地球物理勘探,2006,41(4):396~401
[9]陆基孟.地震勘探原理(上册).山东东营:石油大学出版社,1993
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