The ENERXICO project, and more precisely the oil and gas energies package (WP3), aims to expand the impact of HPC in seismic imaging by analyzing and comparing state-of-the-art modelling and inversion software. The outcome of WP3 must take into account the geological complexities and uncertainties of the subsurface models and the possibility of running multiple scenarios.
Repsol provided a use-case which corresponds to a synthetic model, that incorporates geological heterogeneities and complexities observed in several deep offshore fields in the Gulf of Mexico. The horizontal extension of the model is 90 Km and the vertical extension is 5Km.
The geological complexity of the model resides in:
- The presence of geological formations, mainly composed of clastic rocks extending from the sea-floor to the base of the model.
- The local presence of salt domes with high reflectivity contrast, cutting through the geological formations and forming locally salt canopies (bulbs). The height of the salt stems ranges from 1Km to 3Km. The horizontal extension of the salt canopies can reach 10Km
- The localization of oil-bearing and water-bearing reservoirs are linked to the presence of specific porous formations, and the presence of particular shapes of salt domes.
The model was populated with the following properties:
- Primary wave velocity Vp
- Secondary wave velocity Vs
- Rock density ρ
- Acoustic Impedance AI
Figure 1. Range of Properties
Figure 2. Relationship Vp/Vs and Acoustic Impedance