UTCOMP is an isothermal three-dimensional, EOS compositional reservoir simulator capable of modeling up to four-phase flow, namely, an aqueous phase, an oleic phase, a gaseous phase, and a second nonaqueous liquid phase. A finite-difference method that is third-order correct in space is used to reduce numerical dispersion and grid orientation effects when solving the material balance equations. We have dramatically improved the stability of the third-order method by adding a flux limiter that makes the scheme total variation diminish.
Phase behavior is calculated using the Peng-Robinson equation of state or a modified version of the Redlich-Kwong equation of state. A rigorous Gibbs stability test is performed to determine the number of coexisting phases. A phase identification test is performed to label each phase for subsequent property calculations. Several relative permeability models are available as options. Physical dispersion is modeled using the full dispersion tensor. Some of the applications of UTCOMP are:
- Miscible and immiscible gas injection processes
- CO2 Sequestration in deep saline aquifer and oil reservoirs
- Gas condensate reservoirs
- Tracer tests
- Mobility control using foam or polymer
- Asphaltene precipitation and deposition\