Compartmentalisation is where you have a reservoir that contains...

Compartmentalisation is where you have a reservoir that contains permeability barriers that prevent free movement of fluids laterally within the reservoir. The reservoir is broken up into isolated compartments separated by permeability barriers (eg shaley sections, sealing faults etc) Field wide you might have a gas charged reservoir that maps as a large volume but when you go to flow test or produce you are only able to access a small part of the total reserve and production/flow rates drop off faster than expected.