Simultaneous Q and Velocity Model Building - Incorporating Attenuation to Enhance Model Resolution

We present a new model building workflow for simultaneous building of high resolution Q and anisotropic velocity models. The tomography algorithm uses both travel times and spectral ratios from subsurface seismic data to build the Q model together with the anisotropic velocity model. A consistent spectral analysis is achieved by computing spectral ratios in windows that follow the moveout of events in common image gathers. These simultaneous updates ensure that both the Q- and velocity-models are updated in a kinematically consistent way. The jointly derived earth models are used to perform Q anisotropic pre-stack depth migration. The performance of the new workflow is illustrated with an example from a North Sea dataset with a shallow gas cloud. The results show that QVMB generates high quality anisotropic velocity and Q models that greatly enhance imaging below the gas anomalies.