Abstract: A new method to investigate optimal development decisions of gas-cycling in condensate reservoirs is presented. It is shown that both the oil recovery and the total net present value of a condensate reservoir can be enhanced obviously through optimization of gas production rate, gas injection rate and the mole fractions of each component in injection gas. The corresponding computer program makes a progress in automatic optimal design of development of condensate reservoirs.

Key words: condensate Reservoir, gas-cycling, optimal Control