Ali Shariat - M.ScReservoir Engineer (Petroleum University of Technology
AliReza Behbahani Nia - Kish Petroleum Engineering Director, E members

Naturally fractured carbonate reservoirs contain a significant amount of the world ois reserves. Production mechanisms such as expansion, solution gas drive, oil/water imbibition, and gas gravity drainage may all contribute to production of oil at different stages in the production life of the fractured reservoir. Gas gravity drainage takes place when gas from the gas saturaled fractures displaces oil in the matrix. The free gas may be the gas liberated from the oil that has segregated in the fractures, gas from an expanding gas cap, or gas from gas injection. The density difference between the oil and the gas phases provides the energy for the gas gravity drainage process, Both gas gravity drainage and oil/water imbibition act without depleting the reservoir. Gravity drainage is a gas/oil displacement in which gravity forces are dominating. Main conclusion of this work is that reinfilration causes to reduce the production rate and also in the case of capillary continuity we will have more ultimate recovery in relative to dual porosity model, Also in a stack of blocks oil in a block above always prefers to reinfiltrate in to the block below if there is enough space rather than going through the fractures.