偏移速度分析的精度与观测系统的关系
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摘要
偏移速度是决定叠前地震数据成像质量的最关键参数。叠前偏移速度分析的精度受地震数据的信噪比和分辨率、地震观测系统(主要是观测孔径)及成像方法的影响,很难进行定量的估计。针对此,在常速介质情况下建立了速度估计结果的相对误差与地震数据分辨率、观测孔径及地下反射界面倾角的关系式。利用该关系式,在进行观测系统设计时,可以根据目标反射层的速度估计精度设计观测系统的参数(主要是最大偏移距)。
Migration velocity is the most key parameter for determining the imaging quality of pre-stack seismic data.Accuracy of pre-stack migration velocity analysis is impacted by S/N and resolution of seismic data,geometry(mainly about observation aperture)and imaging method,which is difficult for quantitative evaluation.Aiming at the problem,we established the relation between relative error of velocity evaluation result and seismic data resolution,observation aperture and subsurface reflection interface dip in the medium with constant velocity.By using the relation,we can design geometry parameters according to the velocity evaluation accuracy of target reflection(mainly about maximum offset).
Migration velocity is the most key parameter for determining the imaging quality of pre-stack seismic data.Accuracy of pre-stack migration velocity analysis is impacted by S/N and resolution of seismic data,geometry(mainly about observation aperture)and imaging method,which is difficult for quantitative evaluation.Aiming at the problem,we established the relation between relative error of velocity evaluation result and seismic data resolution,observation aperture and subsurface reflection interface dip in the medium with constant velocity.By using the relation,we can design geometry parameters according to the velocity evaluation accuracy of target reflection(mainly about maximum offset).
引文
1 Al-Yahya K.Velocity analysis by iterative profile migration [J].Geophysics,1989,54(6):718-729
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5 Tieman H J.Investigating the velocity-depth ambiguity of reflection traveltimes[J].Geophysics,1994,59(10): 1763-1773
6 Liu Z,Bleistein N.Migration velocity analysis:theory and an iterative algorithm[J].Geophysics,1995,60 (11):142-153
2 Bickel S H.Velocity-depth ambiguity of reflection traveltimes [J].Geophysics,1990,55(11):266-276
3 Lines L.Ambiguity in analysis of velocity and depth [J].Geophysics,1993,58(4):596-597
4 Ross W S.The velocity-depth ambiguity in seismic t raveltime data[J].Geophysics,1994,59(5):830-843
5 Tieman H J.Investigating the velocity-depth ambiguity of reflection traveltimes[J].Geophysics,1994,59(10): 1763-1773
6 Liu Z,Bleistein N.Migration velocity analysis:theory and an iterative algorithm[J].Geophysics,1995,60 (11):142-153
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