Professional paper
Immiscible-Recycle Gas Injection to Enhance Recovery in an Iranian Naturally Fractured Reservoir: a Case Study with Emphasis on Uncertain Parameters
Navab Rostami
; Islamic Azad University, Science and Research Branch, Tehran, Iran
Ghasem Zargar
; Petroleum University of Technology, Tehran, Iran
Abdolnabi Hashemi
; Petroleum University of Technology, Tehran, Iran
Jamshid Aladaghloo
; Islamic Azad University, Science and Research Branch, Tehran, Iran
Abstract
Recycle-gas injection is a promising recovery process to produce oil and gas. The method uses continues injection of the produced gas at economical rates to keep the reservoirs energy up and using viscous force as the driving force. There are numerous studies done on recycle-gas injection in conventional reservoirs, however, there are some other factors such as location of wells and completion type, rate and pressure of injection which highly affect the final result of this method and failed to be considered in the majority of them.
In this study, we investigate the immiscible recycle gas injection process in one of the Iranian carbonate naturally fractured reservoirs on a field scale. The real heterogeneous model was constructed and simulated by Eclipse-100 module. The effects of operational parameters, such as number and location of injection/production wells, production/injection rate, completion type and interval, on the immiscible gas injection performance were investigated and the result were compared with natural depletion method.
It was found that, in sensitivity with number of the wells, 1 injection/2 production wells was the most efficient case. Also well oil production rate of 3 145 bbl/d (500 m3/d) and well bottom-hole pressure of 25 bar provided higher oil recovery. Completing of the injection wells in fracture and production wells in matrix has a better field oil efficiency in comparison to the other cases. Moreover, it was observed that the most efficient type of well completion for injection well is vertical and for production wells are horizontal. The results revealed that the substantial secondary oil recovery can be achieved using optimum conditions for immiscible recycle gas injection in this reservoir.
Keywords
Immiscible-recycle gas; fractured reservoirs; secondary recovery; operational parameters
Hrčak ID:
111091
URI
Publication date:
30.9.2013.
Visits: 2.739 *