TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractFor the simulation of condensate recovery by lean gas injection below the gas dew point, a common statement is that most of the Black-Oil approaches are not reliable, and that typically 6 to 8 pseudo components in a compositional simulation model are needed, the draw back being a much more considerable computation time.A novel approach, inspired in some extent from BO modeling, has been found adequate to simulate the vaporization effects in the reservoir as lean gas is injected below the dew point. This approach uses a three-component representation of the reservoir fluid. A special attention has been devoted to establish a methodology of practical use for generating the PVT data. To recover the detailed compositional information lost by the use of pseudo components for the dynamic computations, a methodology for delumping the results of the simulation has also been considered.The paper presents firstly the bases of the lumping procedure used for building the ternary representation, the methodology for generating the PVT data, and considerations for delumping the simulation results. Then, test examples are provided, with a comparison between the simulation results obtained with the ternary representation, and with the reference (detailed) compositional representation. Results are shown to be in good agreement, while considerable CPU reduction factors are obtained.