Nabipour - College of petroleum and Chemical Engineering, Shiraz University
Escrochi - College of petroleum and Chemical Engineering, Shiraz University
Ayatollahi - College of petroleum and Chemical Engineering, Shiraz University

It is known that the oil content in matrix porosity in some of the fractured oil reservoirs exceeds more than 90% of the oil originally in place. Minimal recovery factors during the primary stages of production are due to the nature of these reservoirs; geometry and extent of the fracture network, matrix permeability, wettability tendency, as well as the nature of the fluid system. The occurrence of a strong water drive, in some of the fields, becomes even more detrimental to primary recovery. Besides, having very active water drives, some of these reservoirs are already depleted resulting in very high residual oil in place. The oil recovery factor in these reservoirs was also hindered due to heavy oil viscosity as well as very high water cut production during the traditional oil recovery mechanisms. Gas-Oil Gravity Drainage (GOGD) has been found as a very efficient process of secondary and tertiary oil recovery. Temperature effects on the improvement of GOGD process for the recovery of heavy oil has been investigated here. High oil recovery factor was achieved during the multiple processes of free fall gravity drainage, pressure aintenance and thermal simulation from the fractured and non-fractured water-wet sand packed models. It was also noted that a combination of waterflooding and GOGD process is very effective to enhance heavy oil recovery from fractured water-wet porous media.

GOGD, Fractured Reservoirs, Gas Injection, Thermal Enhanced Oil Recovery