Breaking the Limitations of Pressure and Saturation Inversion With a New Dynamic Constraint

The seismic inversion of 4D prestack amplitude information (AVO) can be very non-unique, leading to dubious estimates of dynamic properties. Here we demonstrate a workflow that simultaneously uses the 4D time shift, 4D amplitude and a novel dynamic constraint to invert for much more robust and reservoir consistent changes in elastic parameters. The conversion of these elastic parameters to pressure and saturation yields very promising results. Previously undetectable small-scale changes in pressure are now observed that are coherent with the completion zones of a water injection well.