基于数字滤波的低频信息可控约束波阻抗反演OA

Seismic data generally lacks low-frequency information in a range of 0-5 Hz,so how to effectively compensate for such information constitutes a critical step in improving the objective accuracy of seismic inver-sion.To this end,this paper proposes a digital filtering-based impedance inversion method with controllable low-frequency constraints.First,an inversion objective function is established to match synthetic seismogram de-rived from inversion results with seismic data and impose regularization constraints on reflection coefficients.Second,digital filtering is integrated into the objective function.During inversion iterations,low-pass filters are separately applied to the broadband geological model and inversion results by digital filter,so as to force the low-frequency information of inversion results to conform to that of the geological model.Therefore,the model-driven constraints on inversion results are achieved.Both model test and field application demonstrate that,com-pared with the existing impedance inversion methods,the proposed method only uses the low-frequency informa-tion of the geological model to constrain the low-frequency information of inversion results without distorting the mid-frequency and high-frequency information.Moreover,by regulating the frequency components of low-frequency information via a digital filter,this method offers a novel low-frequency constraint strategy for seis-mic inversion,which effectively enhances the application flexibility of geological models and improves the reso-lution and accuracy of impedance inversion results.