Rouhollah Fatehi

Optimum scenarios for reservoir development planning are evaluated by studying field development options. Gas injection is one of the most popular method for field development. Gas injection projects have been done to improve the recovery efficiency. Gas-oil relative permeability curves are important parameters for gas injection. In this paper, relative permeability of four different fluid systems were investigated using cylindrical shaped sand pack filled with sea sand. 12 sets of dynamic displacement experiments were performed to evaluate the effect of gas flow rate (velocity) on gas and oil relative permeability. In addition to gas-oil relative permeability, oil recovery factor of different fluid systems were investigated, also. Oil and gas relative permeability were determined using one dimensional black oil.The results show increasing both oil and gas relative permeability curves by increasing gas flow rate. Rate effect is more pronounced in oil relative permeability (wetting phase). When gas flow rate increased, in both systems, gas relative permeability (non-wetting phase) shows a little change. Whereas, oil relative permeability changes rapidly. The best scenario for gas injection is using nitrogen as a gas phase for injection at higher rate of 100 cc/min. The highest recovery factor is 44.00 % for experiment number 12 that consist of n-heptane/N2 as a fluid system. There is a good agreement in pressure drop, oil and gas production values between experimental and simulation results. These results show that the calculated relative permeability were quite satisfactory by this method.