Concurrent gas and oil production from the Virginia Hills Belloy Shunda Unit #1 was considered. A full field simulation study was used to evaluate the impact of initiating early blowdown of the gas cap. An excellent match of the production, pressures, and two-phase interface movements was achieved. The model predicts that early blowdown and delayed blowdown cases achieve comparable ultimate oil and gas recoveries. The role of the well established watts fence between the gas cap and oil leg, unique reservoir characteristics and reservoir management strategy, which contribute to this result, are discussed. Research and analytical work was a prerequisite to the simulation study to establish many of the model input parameters. Conformance plots are discussed and used to determine: I) how efficient reservoir depletion has been to date and 2) a residual oil saturation. Results of the simulation study also confirm the input relative permeability curves and trapped gas saturation obtained from referenced studies.