The classical elastic impedance (EI) inversion method, however, is based on the L2-norm misfit function and considerably sensitive to outliers, assuming the noise of the seismic data to be the Guassian-distribution, so a more robust elastic impedance inversion based on the L1-norm misfit function has been developed, and the noise is assumed to be non-Gaussian. Meanwhile, some regularization methods including the sparse constraint regularization and elastic impedance constraint regularization are incorporated to improve the ill-posed characteristics of the seismic inversion problem. Firstly, we create the L1-norm misfit objective function of pre-stack inversion problem based on the Bayesian scheme within the sparse constraint regularization and elastic impedance constraint regularization. And then, we obtain more robust elastic impedances of different angles which are less sensitive to outliers in seismic data by using the IRLS strategy. Finally, we extract the P- and S-wave velocity and density by using the more stable parameter extraction method. A test on the real data set shows that compared to the results of the classical elastic impedance inversion method, the estimated results using the method proposed in this paper can get better lateral continuity and more distinct show of the gas, verifying the feasibility and stability of the method proposed in this paper.
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