Cours. What is a reservoir ? Reservoir geology, formation and interaction with geofluids (3 h). Reservoir properties, heterogeneities, importance of scaling (3 h). Property measurements, flows in reservoir, Darcy equation (3 h). Challenges in reservoir exploitation and global resource management (3 h). Terrain. Two outcrop surveys, carbonate reservoirs and coastal aquifers (9 h). Quantification of reservoir properties, volume, flow, economic aspects (9 h).