Abstract
Optimal production of gas from gas condensate reservoirs have been a major concern to the petroleum industry. Enormous liquid dropout lost to the reservoir during depletion process has been found to restrict the flow of gas near the wellbore, thereby reducing wellbore productivity. The search for the optimal production strategy to produce gas and even the condensed liquid has resulted to the use of enhanced production technique such as gas cycling, water flooding or wettability alteration. Gas cycling is used in gas condensate reservoirs to improve permeability to gas by evaporating the condensed liquid. Where the cycling is commenced early It may defer the dew point pressure. The challenge is the choice of the best production strategy to effectively recover gas trapped by the condensed liquid hydrocarbon and the condensed liquid hence enhancing the productivity of gas condensate reservoirs. In this study, technical and economic approaches are combined to evaluate the potentials of different production strategies using various injection rate and pressures. In the study dynamic uncertainty parameters that influence recovery of gas, condensate and production profile determination are considered. Model that can predict the recovery of gas was developed by the integration of experimental design, fluid characterization and reservoir compositional simulation. The research investigated a range of production strategies in gas cycling project using the predictive model to assess the effects of the reservoir and production parameters on recovery of gas and condensate. The best strategy was established from the optimal injection rate and the effective injective pressure. The work concluded that cycling is best started above dew point pressure. It also established the minimum injection pressure below which gas cycling is uneconomical.
