Connecting well engineers to the geological prospect using acoustics driven earth models

Since the early 1990s, Chevron has maintained a strategy to develop technologies that enable the building of 3D rock mechanical earth volumes from acoustics dominated data sets. This effort has led to the current capability to characterize static elastic moduli of the subsurface in order to apply numerical modeling tools to define in-situ stress attributes across the geological structure. The capability to create rock mechanical properties from the standard P-wave 3D seismic grid enables numerical earth modelers to work alongside well engineers to characterize pre-drill location safe drilling mud weight windows and to forecast drill bit performance through the overburden, i.e., rate of penetration and bit life. Furthermore, a mature 3D formation mechanical property data-set focused on the reservoir can be used to predict seismic attributes that correspond to fluid saturation. Chevron now applies this numerical centric technical capability to business units world-wide for wellbore stability, produced solids prediction, fracture stimulation design, drill cuttings disposal design, bit optimization & performance prediction and seismic reservoir characterization for by-passed oil. We introduce acoustics based rock mechanics concepts, describe an acoustics based rock property prediction technique, and present a field application case for wellbore integrity prediction for a deepwater drilling project in the Gulf of Mexico.