Multi-Mechanistic Flow Domain in Gas Injection for Tight Gas Fractured Reservoirs - Compositional Approach

Gas condensate fractured reservoirs are one of those that molecular diffusion plays an important role in their production mechanism. This paper is the first that investigates the molecular diffusion in gas injection for a gas condensate fractured reservoir. Single block approach is used in this work. This single block is firstly saturated with methane, secondly, methane and ethane and lastly, with methane and n- pentane. Pressure at the left side of this matrix block is kept constant by injection while production is done at the constant pressure at the right side of that. Fully implicit with the using of Newton-Raphson technique is applied to solve highly non-linear equations at this simulation model. In order to speed up the simulation technique, Broyden updating approach is used to update Jacobian matrix. At the end, the most important conclusion is, in gas injection in naturally fractured gas condensate reservoirs, diffusion phenomenon is considerable for matrix blocks with the permeability of lower than 0.01 md in the case of single phase flow at the reservoir condition, while this permeability increases to 0.1 md when two phase flow occurs at the reservoir condition.