Contents lists available at ScienceDirect Fuel journal homepage: www.elsevier.com/locate/fuel Full Length Article A modeling strategy to investigate carbonated water injection for EOR and CO 2 sequestration Cleverson Esene, Sohrab Zendehboudi ⁎ , Amer Aborig, Hodjat Shiri Faculty of Engineering and Applied Science, Memorial University, St. John’s, NL, Canada ARTICLEINFO Keywords: Carbonated water injection (CWI) Grid local pressure CO 2 storage Oil recovery factor Well placement ABSTRACT Carbonated water injection (CWI) has been well investigated to improve oil recovery when compared to other enhanced oil recovery (EOR) techniques both in the secondary and tertiary modes. Extra oil recovery and CO 2 sequestration associated with CWI have been studied through several experimental works. There are not adequate number of modelling studies about the CWI operation in the open sources because of the complex multi-physics involved with the fuid-fuid and fuid-rock interactions during CWI processes. Hence, further experimental and modelling investigations are needed to be conducted on CWI to systematically capture/comprehend the governing physics and complex displacement mechanisms. This research work will focus on the analysis of vital aspects such as oil recovery amount (and mechanisms), fuids distribution, and efects of operational parameters and well placement on the performance of CWI for both EOR and CO 2 sequestration purposes. To achieve these objectives, a 3-D heterogenous reservoir model is developed using the experimental data reported in the recent literature. A new approach of using the grid local pressure to model CWI is adopted where the moles of CO 2 /water are controlled by their injection rates. The dissolution of CO 2 in water is modeled by the Henry’s law for each subsequent grid local pressure. In this research, it is found that through CWI, an additional oil recovery can be achieved when compared to plain (conventional) waterfooding (WF) in the secondary recovery mode. A subsequent increase in the injection pressure leads to more dissolution of CO 2 and enhancement of the overall performance of CWI. There is an op- timum injector rate, which ensures an efective mass transfer across phases. An optimal well orientation will also give a better recovery performance during CWI. The amount of CO 2 stored is also illustrated in this work as an additional beneft achieved in the CWI processes. 1. Introduction The technical/practical challenges associated with reservoir deple- tion have motivated researchers to develop new recovery methods that improve oil recovery factor to meet the ever-increasing energy de- mands. Normally, after primary oil recovery stage, 75%, 95%, and 100% of the original oil in place (OOIP) remain as the residual fuid in the reservoir containing light oil, heavy oil, and tar sands, respectively [1]. Enhanced oil recovery (EOR) methods are usually implemented to considerably reduce the residual oil saturation in the reservoir espe- cially after primary and secondary processes. Conducting EOR pro- cesses, the desired oil recovery for light oil, heavy oil, and tar sands reserves is estimated to be 45%, 90%, and 100%, respectively [1]. After conventional water injection (WI) or water fooding (WF), the injection of CO 2 is normally conducted in most reservoirs to lower the residual oil saturation. Gas injection (GI) has been commonly employed in various felds as a suitable EOR method, though it is associated with some demerits [2]. For example, a poor sweep efciency attributed to the high mobility of CO 2 gas has been reported during CO 2 injection. This poor displacement process is due to the large contrast between the fuid densities (oil and gas) and hence high mobility of CO 2 gas, compared to oil [2]. Gravity segregation (override) is another issue where the in- jected CO 2 migrates to the top of the reservoir leaving behind a con- siderable area of unswept zones because of early gas breakthrough in the production wells. To overcome the problems associated with pure CO 2 injection, alternative EOR methods such as CO 2 foam fooding, water alternating gas (WAG), polymer fooding, simultaneous water alternating gas (SWAG), and low salinity water injection (LSWI) have been developed at the laboratory, pilot, and feld scales. Esene et al. [32] recently performed a modelling investigation on low salinity water injection (LSWI) in sandstone and carbonate reservoirs. In their re- search, it was reported that oil recovery is improved in the LSWI pro- cess when compared to the plain/conventional WF. However, there was a high mobility ratio because of the considerable diference between the https://doi.org/10.1016/j.fuel.2019.04.058 Received 22 January 2019; Received in revised form 8 April 2019; Accepted 10 April 2019 ⁎ Corresponding author. E-mail address: szendehboudi@mun.ca (S. Zendehboudi). Fuel 252 (2019) 710–721 0016-2361/ © 2019 Elsevier Ltd. All rights reserved. T