A hydrocarbon-bearing reservoir is buried deep in the subsurface and typically exists in a high-pore-pressure state. The weight of the formation deposited above the reservoir (overburden) is supported by both the rock matrix and the fluid pore pressure. During oil or gas production, the pore pressure depletes and the overburden compacts the reservoir, causing the surface to subside.

To obtain the necessary legal permits to begin production from a reservoir, surface subsidence must be limited in accordance with the requirements of the given jurisdiction. Minimal subsidence is especially critical when the reservoir is located within the vicinity of a populated area.

The example simulation presented here predicts the surface subsidence caused by a uniform pressure depletion of a completely compartmentalized disc-shaped reservoir. The problem considers the effects of reservoir depth, radius, and height on compaction and surface subsidence. The correlation of maximum surface subsidence to geometric parameters is shown to closely match the trends of the reference analytical solution.[1]