The role of shale pressure diffusion in 4D seismic reservoir monitoring - case studies

The low but non-negligible permeability of shale enables pressure diffusion; the elastic implications of this process are sizeable over the production lifetime and can be recorded by time-lapse seismic monitoring (Ricard et al. 2012). To assess this effect our study include the internal architecture analysis of the shale in the 3D and 4D seismic modeling of two field applications: a shallow marine and a turbidite reservoir, where shale permeability, sand - shale geometry, time, reservoir connectivity and compartmentalization, determinate the impact of pressure diffusion in generating 4D signal related to changes in saturation (gas coming out of solution) and pressure.