各向异性地层深度域速度建模

Velocity modeling in depth domain of anisotropic stratigraphic

提出了一种新的方法来更新纵波和转换波的深度域速度模型。该方法基于矢量波波场延拓的弹性波叠前深度偏移得到的共成像点的剩余曲率分析(RCA)。在共成像点道集上进行速度更新,并将偏移速度与真实速度的差异参数化,通过拾取能量团的方式估计真实速度。同样的方法也可用于更新各向异性参数。推导了成像深度与各向异性参数关系的方程,并利用模型各向异性和真各向异性的相关参数更新了横向各向同性介质(VTI)的各向异性参数。在实际应用中,采用分层剥离法逐层更新速度,通过剩余时差反演各向异性参数。利用合成地震资料和实际工区模型资料进行验证,验证了偏移速度更新方法和各向异性参数分析方法的可行性和准确性。

A new method was proposed to update the depth-domain velocity models for longitudinal and converted waves.The method was based on residual curvature analysis(RCA)of common imaging points obtained by elastic wave prestack depth migration of vector wave wavefield continuation.The velocity update was performed on the common imaging point gather,and the difference between the offset velocity and the true velocity was parameterized,and the true velocity was estimated by picking up energy clusters.The same method could also be used to update anisotropy parameters.The equation of the relationship between the imaging depth and the anisotropy parameters was derived,and the anisotropy parameters of the transversely isotropic medium(VTI)were updated using the relevant parameters of the model anisotropy and true anisotropy.In practical applications,the layer-by-layer peeling method was used to update the speed layer by layer,and the anisotropy parameters were inverted through the residual time difference.The synthetic seismic data and the actual work area model data were used to verify the feasibility and accuracy of the migration velocity update method and the anisotropic parameter analysis method.