Enhanced Oil Recovery (EOR) Process through Miscible Gas Injection: A Case Study of an Iranian Oil Reservoir

Abstract

Speedy computers and development in equations’ numerical solutions have enhanced applying simulation to predict the behavior of oil and gas reservoirs. The pressure in hydrocarbon reservoirs reduces overtime due to utilization of oil and gas resources until the fluid pressure itself is no more able to transfer it to the surface, and even if it reaches to the surface, its production is not cost-effective. Whereas, large amounts of hydrocarbon resources still remain within reservoir’s pores. In order to make reservoir produce as much as possible and increase its recovery factor at different stages of reduced reservoir pressure, different operations are performed on reservoirs. One of these methods is gas injection operations. Gas injection efficiency in reservoirs has been historically doubted as a useful mechanism; however, since 1950s, it is considered as an appropriate method to stabilize pressure and oil production; in addition to a proper approach to recover residual oil following water injection. Miscible and immiscible gas injections are both widely used; as the nature of Iranian reservoirs’ rocks, which are almost carbonated and oil wet.

Keywords: Enhanced oil recovery (EOR), miscible gas injection, reservoir simulation, fractured reservoirs