Application of the SAGD to an Iranian Carbonate Heavy-Oil Reservoir

Abstract Steam injection is the most important thermal enhanced oil recovery; while in this method Steam-Assisted Gravity Drainage (SAGD) is a very promising recovery process to produce heavy oils and bitumen. The method ensures both a stable displacement of steam and economical rates by using gravity as the driving force and a pair of horizontal wells for Injection/production. SAGD in Sandstone heavy oil Reservoirs has been characterized quite well over the last years. However, there is huge carbonate heavy oil reserves in the world which their production can be enhanced by thermal recovery processes, especially by steam injection. In this study, Application of SAGD to an Iranian heavy oil carbonate reservoir with low matrix permeability has been investigated. Field-Scale 3-D and simulation models were constructed by using commercial softwares and by thermal simulators to investigate SAGD performance in this reservoir. The model was further applied to a fractured system and effects of fracture and matrix permeability, Vertical well spacing between producer and Injector and Length of the horizontal section of the injection well on the performance of SAGD process were studied. By comparison with other thermal methods results showed that SAGD can be used as a better EOR method for this heavy oil carbonate reservoir.