Sharif Digital Repository

Today, due to limited number of light oil reservoirs, enhanced recovery from heavy oil reservoirs is taken into consideration. During the early production from heavy oil reservoirs, due to high viscosity, only a small amount (about 5%) of the oil can be produced; also after water injection operation due to unfavorable mobility ratio of water and oil, sorely more than about 10% of the original oil can be produced. On the other hand, fractured reservoirs represent about 20% of the world's oil reserves, while over 60% of the world's remaining oil reserves are in fractured reservoirs. Water flooding process leaves very high amounts of oil as remaining oil in these reservoirs too. One of the... 

Naturally fractured oil reservoirs represent over 20% of the world's oil reserves, while over 60% of the world’s remaining oil lies trapped in fractured reservoirs. However, relatively little success has been achieved in increasing oil production from these complex reservoirs. Water flooding process leaves much oil in the reservoir, especially in fractured reservoirs. Surfactant flooding is known to lower the interfacial tension and hence, reduces capillary forces responsible for trapping oil and increasing recovery. However, fundamental understanding how the fracture geometrical properties affect the oil recovery efficiency during surfactant flooding remains a topic of debate in the... 

Due to the importance of enhanced oil recovery of heavy oil fractured reservoirs, in this work micromodel setup has been used to study the miscible solvent injection in five-spot fractured reservoirs with different fracture geometrical characteristics. Due to the visual nature and flexibility of the micromodel patterns it is a subject of interest to be used in different studies. Different patterns has been constructed by chemical etching and controlled laser etching and saturated with displaced fluid and flooded by constant rate injection of hydrocarbon solvent in abient temperature and pressure. At first, effect of fracture’s length, numbering, orientation, discontinuity and scattering on... 

Enhancing oil production from fractured reservoirs is challenging. The flow characteristics observed in naturally fractured reservoirs are complicated due to interaction between the two different flow domains: fracture and matrix. Spontaneous imbibition is one of the most important recovery processes in water-wet fractured reservoirs. Oil cannot be spontaneously produced from oil-wet rocks, unless the capillary pressure barrier between fracture conduits and matrix is overcome. The flow characteristics in fractured systems thus relate to the wettability of the rocks. Low salinity water injection has been widely studied as a method of enhancing oil recovery in recent years. However, its impact...