| The vertical seismic profile(VSP)can help to understand the characteristics of seismic wavelet propagation and lay a foundation for the joint application of borehole seismic information.High-resolution wave impedance inversion based on VSP data can help to obtain high-precision calibration and reservoir distribution information.The complementary advantages of the VSP and surface seismic data can improve the inversion accuracy.The absorption attenuation property of the formation can be reflected by quality factor Q.The Q value extracted from the VSP data can help to recover the phase and amplitude energy of seismic waves,thereby improving the resolution of the data.Above all,this paper studies a processing flow of high-resolution wave impedance inversion method for VSP data.First,calculate the Q value from the VSP down-going wave record,and then uses the inverse Q filtering algorithm to compensate the attenuation effect.Second,extract the wavelet from the VSP down-going wave record and establish the initial model for inversion.Third,based on the least square theory,perform the highresolution wave impedance inversion on VSP corridor stack record.Among which,introduce the Marquette method and the preconditioned conjugate gradient method to enhance the stability and convergence speed of inversion.The synthetic data tests illustrate the effectiveness of this method.Afterwards,apply the high-resolution wave impedance inversion method on the actual VSP data from the Ordos Basin.The initial model for inversion is established by velocity analysis on the VSP data and the wave impedance results with high-resolution are obtained by wave impedance nonlinear inversion method.Finally,the high-resolution zero-offset VSP corridor and walkaway VSP-CDP imaging are inlaid calibrated,and the joint meticulous layer calibration between the VSP data and the surface seismic data in the study area has been acquired,which has a relatively good performance. |
PDF Full Text Request