Utilization of Co3O4 nanoparticles for reducing precipitation of asphaltene during CO2 injection

作者：Hassanpour S; Malayeri M R; Riazi M^*

来源：Journal of Natural Gas Science and Engineering, 2016, 31: 39-47.

DOI：10.1016/j.jngse.2016.03.010

• Enhanced oil recovery
• Gas injection
• Interfacial tension
• Asphaltene precipitation
• Nanoparticle

Injection of CO2, as a redundant gas, is considered as one of the most viable options to enhance oil recovery. The performance of this process may though be compromised in the event of severe precipitation and deposition of asphaltene. In this study, the effect of Co3O4 nanoparticles with various concentrations of 0.01, 0.1 and 1.0 wt% on precipitation of asphaltene during CO2 injection was investigated by means of interfacial tension (IFT) measurements. The addition of Co3O4 nanoparticles to synthetic solutions comprising of n-heptane, toluene and 5 wt% asphaltene and crude oil caused the IFT to decrease linearly as a function of pressure with two different slopes. In the first region, CO2 dissolved in the oil phase while in the second region, asphaltene was prone to precipitation. The IFT reduced at lower slope in the second region. It was found that the addition of nanoparticles to the synthetic and crude oils resulted in more asphaltene particles adsorption on the surface of nanoparticles. In addition, more stable dispersion of asphaltene nano-aggregates could be attained. Consequently, the ultimate recovery of asphaltenic oil would take place in reservoir conditions during CO2 injection due to less aggregation and precipitation of asphaltene particles. Finally, the optimum concentration of dispersed Co3O4 nanoparticles was found to be 0.1 wt%.

• 出版日期2016-4