Experimental investigation of the effect of Vitagnus plant extract on enhanced oil recovery process using interfacial tension (IFT) reduction and wettability alteration mechanisms

Seyed Ramin Mousavi Dashtaki,Alireza Keshavarz,Iman Nowrouzi,Amir H Mohammadi,Abbas Khaksar Manshad,Jagar A Ali

doi:10.1007/s13202-020-00966-6

Abstract

Surfactant flooding is a chemical enhanced oil recovery (cEOR) process wherein anionic, cationic, non-ionic, and amphoteric surfactants are injected into oil reservoirs to produce more hydrocarbon. These chemical and industrial agents might cause some economic and environmental challenges. Recently, injection of natural surfactants, as new environmentally friendly EOR agents, for improving oil recovery has been proposed by researchers. In this study, the extract of Vitagnus, a natural surfactant, was used to minimize the interfacial tension (IFT) and alter the rock wettability towards the strong water-wet system, thereby improving the oil recovery from the carbonate rock The conductivity, pH, and turbidity measurements were undertaken to identify the critical micelle concentration (CMC) of the surfactant solutions prepared by mixing 500, 1000, 2000, 3000, 4000, 5000, 6000, and 7000 ppm of the Vitagnus extract and distilled water. The obtained experimental results reveal that the optimum CMC value of the used surfactant was 3000 ppm. At this CMC value, the IFT reduced from 29.5 to 5.28 mN/m, and the contact angle of the oil droplet on the surface of the carbonate rock decreased from 114° to 29°. Accordingly, during the tertiary process, oil recovery was improved from 44% to 54.6% OOIP (original oil in place) by injecting 2.25 PVs of the VIT3000 surfactant containing 3000 ppm of the plant extract.

Highlights

Tertiary processes of oil recovery are applied to extract the trapped oil from the matured oilfields due to influencing the interactions of fluid/fluid and/or fluid/rock (Ali and Stephen 2018; Ali et al 2018; 2019a, b, c; Najimi et al 2019; Asl et al 2019; Howe et al 2015)
The ultimate goal of this study was to investigate the influence of the Vitagnus plant extract, as a natural surfactant, on improving oil recovery from carbonate reservoirs
In this study in accordance with Ahmadi and Shadizadeh (2013b), we considered the electrical conductivity approach to identify the critical micelle concentration (CMC) of the developed natural surfactant (VIT solution)

Summary

Introduction

Tertiary processes of oil recovery are applied to extract the trapped oil from the matured oilfields due to influencing the interactions of fluid/fluid and/or fluid/rock (Ali and Stephen 2018; Ali et al 2018; 2019a, b, c; Najimi et al 2019; Asl et al 2019; Howe et al 2015). The IFT and the contact angle can be reduced by injecting the surfactant solutions into the oil reservoirs (Manshad et al 2017; Ahmadi and Shadizadeh 2018; Hanamertani et al 2017; Olayiwola and Dejam 2019). Surfactant flooding is one of the effective cEOR methods that displace the trapped crude oil in the pore spaces towards the production wells (Najimi et al 2019; Asl et al 2019). According to Wang et al (2010), the volumetric sweep (microscopic) efficiency has a great role in the displacement of hydrocarbons at the pore scale, which is affected by the capillary and viscous forces. On the basis of the relationships between these two forces, a number of capillaries are formed, which are controlled by IFT, viscosity, and contact angle (Bera et al 2013).

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Conclusion