Nolen, J.S., Member AIME INTERCOMP Resource Development and Engineering, Inc.
The only fundamental difference between compositional reservoir simulators and simulators of the black-oil type lies in their treatment of fluid properties and phase behavior. Since properties and phase behavior. Since compositional simulation, the only justification for a compositional study is the increased accuracy that can be obtained by a more realistic description of the fluid.
This paper focuses on the consistent and accurate treatment of fluid properties in describing a three dimensional properties in describing a three dimensional compositional simulator. It describes the methods used to calculate densities, viscosities, and equilibrium K-values, presenting comparisons between calculated values and experimental data.
Another subject of discussion in the paper is the problem of numerical dispersion. An example simulation illustrates the magnitude of the problem and demonstrates that the method-of-characteristics provides a practical means of eliminating numerical provides a practical means of eliminating numerical dispersion in multicomponent miscible displacement problems.
Most numerical simulations of petroleum reservoirs are performed with petroleum reservoirs are performed with "black-oil" type simulators. The validity of these black-oil models rests on the assumption that the reservoir fluid consists of only two components, denoted oil and gas.