Multiparameter Full-Waveform Inversion for Velocity and Attenuation Reconstruction Using Nearly-Constant Q Models

Precise modeling of the attenuation parameter Q is important to confirm the robust and diagnostic attenuation characteristics of seismic waveforms in oil and gas reservoirs. For this purpose, the nearly constant Q viscoacoustic wave equation is beneficial. Compared with attenuation models such as standard linear solid (SLS), the wave equation corresponding to the nearly constant Q model contains an explicit Q, which is conducive to inversion and can provide a more effective parameterization. This parameterization facilitates the initial suppression of parameter crosstalk in multiparameter inversion. We derive the adjoint equation containing auxiliary variables, compare the sensitive kernels of different parameterizations, and explain the superiority of the constructed parameterization. The truncated Gauss-Newton (GN-TRN) method is introduced to suppress parameter crosstalk further. The GN-TRN method updates the model parameters by calculating the Hessian vector product and iteratively solving the approximation of the Newton gradient directions. The test results of the theoretical model and field data verify the effectiveness and stability of the inversion method.