Numerical simulations using reservoirA subsurface body of rock with sufficient porosityMeasure for the amount of pore spaceSpace between rock or sediment grains that can contain fluids in a rock and permeabilityAbility to flow or transmit fluids through a porous solid such as rock to store and transmit fluids parameters and a simple geomechanical model based on rock and fluid compressibilities can be performed with the commercial simulator GEM from Computer Modelling Group (CMG).