ChemSim is a non isothermal three-dimensional chemical flooding simulator. The solution scheme is analogous to IMPES, where pressure is solved for implicitly, but concentrations rather than saturations are then solved for explicitly. Phase saturations and concentrations are then solved in a flash routine. An energy balance equation is solved explicitly for reservoir temperature. The energy balance equation includes heat flow between the reservoir and the over- and under-burden rocks.

The major physical phenomena modeled in the simulator are: • dispersion/diffusion • dilution effects • adsorption for surfactant and polymer • interfacial tension • relative permeability • capillary pressure • capillary trapping • cation exchange • phase density • compositional phase viscosity • phase behavior (pseudoquaternary) • partitioning of chemical species between oil and water • cation exchange reactions involving more than two cations • polymer properties: shear thinning/thickeneing viscosity, inaccessible pore volume, permeability reduction, adsorption • gel properties: viscosity, permeability reduction, adsorption • tracer properties: partitioning, adsorption, radioactive decay, reaction (ester hydrolization), • temperature dependent properties: viscosity, tracer reaction, gel reactions, Surfactant phase behavior