Petroleum reservoirs show variations in pressure, temperature and composition with depth. This is the result of gravity segregation and thermal effects. Calsep uses a model based on irreversible thermodynamics to account for the thermal effects and offers consulting services to model PVT property variations with depth. The depth of a Gas-Oil Contact (GOC) can be predicted or the depth gradient model can be configured to match an observed GOC.
For fluids with asphaltene components Calsep can simulate the variations in composition, saturation point, and asphaltene onset point with depth and identify the location of a possible tar mat.