Numerical investigation of two-phase flow encountered in electrically enhanced oil recovery

Abstract

The study of two-phase immiscible flow in porous media using electrokinetics is important in different fields including the remediation of hydrocarbon contaminated soils and enhanced oil recovery. While electrokinetic technology has been traditionally used for treatment and decontamination of hydrocarbon polluted sites, electrically enhanced oil recovery (EEOR) is relatively new. Although a few laboratory and field experiments have investigated the potential promise of the EEOR method, further investigation is necessary to better understand the fundamentals and the importance of different parameters/ processes that affect the oil production in this method. This study presents a numerical investigation of two-phase flow in EEOR method in an attempt to provide insight into the feasibility of, and the important parameters involved in this method. A sensitivity analysis is performed on important parameters involved in EEOR combined with water flooding. Most of the investigated reservoir and operational parameters were found to be significant and critical to the transport phenomena controlling the oil production. In addition, the results showed that the applied electrical gradient involved in EEOR combined with water flooding contributes to a small increase in oil production.

Effect of direct current on gas condensate droplet immersed in brine solution

“…2 Schematics of gas condensate banking (Ikpeka et al 2020) have shown significant improvement in oil recovery when direct current is passed through the core samples (Ansari et al 2015b;Ghosh et al 2012;Hill 2014;Yim et al 2017;Wentong Zhang et al 2019a, b). Numerical investigation conducted by Peraki et al (2018) reported an increase in oil recovery when electric current is combined with waterflooding. The improved recoveries observed in these studies were attributed to electrical double layer expansion of oil-brinerock interface, movement of charged ions from the anode to the cathode, drag-force transfer of water molecules associated with charged ion movement, disintegration of water molecules into constituent gaseous and ionic phases, movement of colloid particles, viscosity reduction and thermal mobility of reservoir fluid (Ghazanfari et al 2012;Haroun et al 2009;Peraki et al 2018;Wittle et al 2011).…”

“…Numerical investigation conducted by Peraki et al (2018) reported an increase in oil recovery when electric current is combined with waterflooding. The improved recoveries observed in these studies were attributed to electrical double layer expansion of oil-brinerock interface, movement of charged ions from the anode to the cathode, drag-force transfer of water molecules associated with charged ion movement, disintegration of water molecules into constituent gaseous and ionic phases, movement of colloid particles, viscosity reduction and thermal mobility of reservoir fluid (Ghazanfari et al 2012;Haroun et al 2009;Peraki et al 2018;Wittle et al 2011). Some factors affecting the efficiency of EEOR in oil reservoirs include brine salinity, hydrocarbon composition (presence of polar components as found in asphaltenes), rock mineral composition and the amount of direct current passed through the reservoir.…”

Effectiveness of electrokinetic-enhanced oil recovery (EK-EOR): a systematic review

“…The introduction of electric current into the reservoir, has shown significant improvement in hydrocarbon recovery based on laboratory studies [18,64,65] and preliminary field deployment [36,37,46]. The improved recoveries observed in these studies were attributed to electrical double layer expansion of oil-brine-rock interface, movement of charged ions from the anode to the cathode, drag-force transfer of water molecules associated with charged ion movement, disintegration of water molecules into constituent gaseous and ionic phases, movement of colloid particles, viscosity reduction, and thermal mobility of reservoir fluid [32,34,49,62]. Hill [36], while using the concept of coupled flow, identifies 5 mechanisms that occur when electric current is introduced to the reservoir: Joule heating, electromigration, electrophoresis, electroosmosis, and electrochemically enhanced reactions.…”

“…Expressing ∇ 2 in terms of cylindrical coordinates (x, r, θ), and assuming ϕ and u e are independent of x and θ [49],…”

“…The effect of electroosmosis becomes more pronounced as the hydrodynamic permeability decreases. Peraki et al [49] performed a sensitivity analysis to investigate key parameters that affect electrokinetic flow. Results from their numerical analysis revealed absolute electro-osmotic permeability was a key factor among other factors which include porosity, initial water saturation, applied current density, water resistivity, and applied current density.…”