Envelope inversion(El)is an efficient tool to mitigate the nonlinearity of conventional full waveform inversion(FWI)by utilizing the ultralow-frequency component in the seismic data.However,the performance of envelope...Envelope inversion(El)is an efficient tool to mitigate the nonlinearity of conventional full waveform inversion(FWI)by utilizing the ultralow-frequency component in the seismic data.However,the performance of envelope inversion depends on the frequency component and initial model to some extent.To improve the convergence ability and avoid the local minima issue,we propose a convolution-based envelope inversion method to update the low-wavenumber component of the velocity model.Besides,the multi-scale inversion strategy(MCEI)is also incorporated to improve the inversion accuracy while guaranteeing the global convergence.The success of this method relies on modifying the original envelope data to expand the overlap region between observed and modeled envelope data,which in turn expands the global minimum basin of misfit function.The accurate low-wavenumber component of the velocity model provided by MCEI can be used as the migration model or an initial model for conventional FWI.The numerical tests on simple layer model and complex BP 2004 model verify that the proposed method is more robust than El even when the initial model is coarse and the frequency component of data is high.展开更多
Full waveform inversion is a fitting process based on full seismic wave field simulation data using the full waveform information in seismic records and theoretically it is the ultimate goal of seismic inversion. Howe...Full waveform inversion is a fitting process based on full seismic wave field simulation data using the full waveform information in seismic records and theoretically it is the ultimate goal of seismic inversion. However,there are many problems to be solved in practical application. Firstly,it is the strong nonlinear problem between the seismic wave field and inversion parameters; secondly,the lack of low-frequency information in seismic records. In this study,the envelope is used as objective function inversion to provide the inversion result for the multi-scale full waveform inversion as the initial model,solving the lack of low-frequency information in seismic records. Taking the envelope of seismic records as the objective function in combination of multi-scale full waveform inversion became a new inversion strategy,which naturally achieved the compensation of shortage of low-frequency information and inversion from low frequency to high frequency,reducing the non-linearity in the inversion process. The comparison of the result of full waveform inversion of the initial model built through envelope inversion with the result of the conventional multi-scale full waveform inversion indicates the effectiveness of envelope inversion for the recovery of low-frequency information in seismic records.展开更多
基金supported by the National Science Foundation(Grant No.41104069,41274124)National“973 Project”(Grant No.2014CB239006)+1 种基金National Oil and Gas Project(Grant No.2016ZX05014001,2016ZX05002)supported by Tai Shan Science Foundation for the Excellent Youth Scholars.
文摘Envelope inversion(El)is an efficient tool to mitigate the nonlinearity of conventional full waveform inversion(FWI)by utilizing the ultralow-frequency component in the seismic data.However,the performance of envelope inversion depends on the frequency component and initial model to some extent.To improve the convergence ability and avoid the local minima issue,we propose a convolution-based envelope inversion method to update the low-wavenumber component of the velocity model.Besides,the multi-scale inversion strategy(MCEI)is also incorporated to improve the inversion accuracy while guaranteeing the global convergence.The success of this method relies on modifying the original envelope data to expand the overlap region between observed and modeled envelope data,which in turn expands the global minimum basin of misfit function.The accurate low-wavenumber component of the velocity model provided by MCEI can be used as the migration model or an initial model for conventional FWI.The numerical tests on simple layer model and complex BP 2004 model verify that the proposed method is more robust than El even when the initial model is coarse and the frequency component of data is high.
基金Supported by Project of National Natural Science Foundation of China(No.41274120)
文摘Full waveform inversion is a fitting process based on full seismic wave field simulation data using the full waveform information in seismic records and theoretically it is the ultimate goal of seismic inversion. However,there are many problems to be solved in practical application. Firstly,it is the strong nonlinear problem between the seismic wave field and inversion parameters; secondly,the lack of low-frequency information in seismic records. In this study,the envelope is used as objective function inversion to provide the inversion result for the multi-scale full waveform inversion as the initial model,solving the lack of low-frequency information in seismic records. Taking the envelope of seismic records as the objective function in combination of multi-scale full waveform inversion became a new inversion strategy,which naturally achieved the compensation of shortage of low-frequency information and inversion from low frequency to high frequency,reducing the non-linearity in the inversion process. The comparison of the result of full waveform inversion of the initial model built through envelope inversion with the result of the conventional multi-scale full waveform inversion indicates the effectiveness of envelope inversion for the recovery of low-frequency information in seismic records.
