Seismic inversion with accuracy and efficiency

We present an inversion methodology using a combination of prestack waveform inversion and simultaneous inversion of amplitude-variation-with-offset data (simultaneous AVO inversion). In this approach, we run prestack waveform inversion at well controls and other sparse locations away from the wells over the entire seismic data to obtain detailed descriptions of the elastic earth models for these locations. These elastic earth models are then used as pseudo well controls for simultaneous AVO inversion of the entire seismic data. Application of our methodology on real data illustrates that our approach provides a better definition of subsurface properties compared to a standard simultaneous AVO inversion that uses the well controls but no pseudo well controls from prestack waveform inversion. This improvement is primarily due to the fact that prestack waveform inversion provides reliable and consistent low-frequency earth models. These low-frequency models, interpolated smoothly over the interpreted horizons allows a better definition of subsurface reservoir properties from simultaneous AVO inversion compared to the same where the low-frequency model is derived only from the well information.