Influence of Silica Nanofluid on CO₂ Mass Transfer and Hydrocarbon Property Alteration in a Carbonated Water-Hydrocarbon System

Abstract

The study investigates the impact of a nanofluid suspended in carbonated water (CW) on the CO2 mass transfer into hydrocarbon in a carbonated water/hydrocarbon system. Furthermore the study addresses into the influence of the nanofluid assisted CO2 mass transfer on the viscosity and density of hydrocarbon and its relevance to enhanced oil recovery (EOR). The experiments were carried out at 10-70 bar at 25°C and 45°C using an axisymmetric drop shape analysis (ADSA) for three concentrations of silica nanofluid (0, 0.05, 0.5, and 1.0 g/l). A pressure decay method was used to estimate the change in CO2 solubility in water in the presence of the nanofluid. A mathematical model coupled with experimental input was used to quantify the mass of CO2 transferred into the hydrocarbon from the CW. Although this work does not address the EOR process, it indicates its applicability for EOR. The results showed that the dispersed nanofluid in CW enhanced the CO2 mass transfer into the hydrocarbon, and reduced the hydrocarbon viscosity and density. The pressure decay experiments indicated that the nanofluid increases the mass of CO2 in water by 17% compared to that without nanofluid. Compared to CW, CNF (CW+nanofluid) increased the CO2 mass transfer into the hydrocarbon drop by approximately 2% at 10 bar and 45% at 60 bar, this leads to an increment in volume of the pendant drop by approximately 3% at 10 bar and 48% at 60 bar at 25°C. A similar observation was made at 45°C. The nanofluid through CO2 mass transfer was responsible for approximately 40% and 29% reduction in the viscosity and density respectively, when compared with CW. Compared to CO2/hydrocarbon the CNF/hydrocarbon lead to a 17.3% volume increase at 30 bar to 91.2% at 50 bar. The increase in the drop volume is unlikely to be due to the migration of nanofluid across the interface into the hydrocarbon drop as indicated by analysis done using UV spectrophotometry and may be due to increase in the CO2 concentration gradient across the interface due to increase in the CO2 solubility in CW.

Enhanced Oil Recovery and CO2 Storage by Enhanced Carbonated Water Injection: A Mini-Review

“…As shown in Figure , the addition of 0.021 and 0.04 wt % nanoparticles to CW led to oil recovery of 50.91% and 48.18%, respectively, significantly surpassing the recovery obtained with conventional CW injection (45.76%). Research conducted by Bagalkot et al also confirmed that nanofluids can increase the CO 2 content in CW and facilitated the mass transfer of CO 2 from water to crude oil . After adding nanofluids, the CO 2 content in water increased by 17%.…”