TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe VLE WAG pilot in Maracaibo Lake is one of the laboratory IOR fields of the State Venezuelan Oil Company PDVSA. The area of the VLE WAG pilot encompasses 5 production wells, one injection well and one observation well.The producing reservoir C-23 is stratified heterogeneous sandstone. The WAG injection pilot in the VLE field is planned to start in year 2000. The main objective of the WAG pilot is to improve oil recovery from the area being produced since 1991 under natural pressure depletion.Available data were integrated to have representative description of the reservoir and fluids simulation model. The stochastic description of the C-23 reservoir was used to build the model of the pilot area. Available well data were used to condition the stochastic geological model. Core flood experiments were simulated and interpreted to establish relative permeability data. The available PVT data from different production time periods was reviewed and black oil fluid description was established to account for injection hydrocarbon gas dissolution and oil swelling effects under WAG injection. The established simulation model was used to history match production data and to evaluate WAG injection scenarios. The injection well has dual completion for separate simultaneous water and gas injection cycles. Cyclic simultaneous water and gas injection in the VLE WAG pilot has a potential to improve waterflooding recovery by 5-7% of STOOIP after 5 years of production. The planned tracer injection program will provide additional data for further simulation model adjustments and improvements. This paper will discuss the integration of data to establish a representative simulation model, history matching and WAG process modelling, VLE WAG laboratory field evaluation.