Effect of Nanoparticles on Asphaltene Aggregation in a Microsized Pore

Abstract

During oil recovery process, the equilibrium state of asphaltene−oil solution system and colloidal system in porous media is altered, which could cause asphaltene to precipitate from crude oil in rock pores. This severely results in the alteration of wettability, permeability, and porosity of formation and damages oil reservoir formation. Nanoparticles have recently been considered as effective asphaltene inhibitors. Several experimental works were carried out to study the impact of nanoparticles on asphaltene precipitation. The majority of these studies were performed using coreflooding experiments in bulk phase. However, few experimental investigations were performed to directly reveal the impact of nanoparticles on asphaltene aggregation based on the direct pore-scale visual evidence. In this work, a novel method was employed to make direct visualization and measurement on the kinetics of asphaltene aggregation in the presence of nanoparticles in a microcapillary. NiO, SiO 2 , and Fe 3 O 4 nanoparticles were used. We directly measured the diameter and number and analyze size distribution of asphaltene aggregate particles in a microsized pore. The results indicate that the nanoparticles can significantly inhibit the aggregation of asphaltene particles in a microsized pore due to adsorption of asphaltene particles onto nanoparticle surfaces. The effect of nanoparticle concentration was investigated. Higher concentration of nanoparticles could contribute to the inhibition of aggregation of asphaltene particles. The asphaltene precipitation and aggregation can be prevented more effectively at higher concentration of asphaltene precipitant in the presence of nanoparticles.

Characterization of bitumen and a novel multiple synergistic method for reducing bitumen viscosity with nanoparticles and surfactants

“…Although the asphaltene content in the toluene solution was low, asphaltene precipitants increase the viscosity, and asphaltene agglomerates increase with increasing asphaltene concentration. 12,[41][42][43] This is consistent with the results obtained by Hemmati-Sarapardeh et al 44 3.3 Effects of SARA composite concentrations on viscosities of SARA-toluene solutions Fig. 6 shows the effect of SARA composite concentrations on the viscosities of the SARA-toluene solutions.…”

“…Asphaltene has a high percentage of heteroatoms (N, O, S, and metals), and its self-aggregation effect will further increase the structural complexity of bitumen. [11][12][13] However, studies on the inuence of other components on the viscosity of bitumen, including saturates, aromatics, and resins, are lacking. In addition, the relationship between the different subfractions in increasing the bitumen viscosity is unclear.…”

Interfacial and Confinement-Mediated Organization of Gas Hydrates, Water, Organic Fluids, and Nanoparticles for the Utilization of Subsurface Energy and Geological Resources

“…Various nanoparticles in porous media were found to inhibit asphaltene aggregation and deposition under reservoir conditions and facilitated successful flow through the studied porous media . NiO, SiO 2 , and Fe 3 O 4 nanoparticles in the micropores of glass square borosilicate capillaries inhibited the aggregation of asphaltenes with higher concentrations of nanoparticles having a higher impact on asphaltene aggregation . A detailed summary of the inhibition effect of various nanoparticles on asphaltene aggregation is listed in Table .…”

“…The thermodynamics and kinetics of asphaltene assembly in confinement differ from that of bulk fluids due to the effects of pore size and surface chemistry. ,,, The self-assembly of asphaltenes is influenced by asphaltene concentrations and solvent compositions, − the presence of injection agents such as water, air, and CO 2 , ,, and temperature and mechanical conditions. , Smaller asphaltene aggregates are observed in confinement compared to in bulk solvents due to adsorption on the interior surface of the confining pores . Further, pores with diameters larger than 5 nm showed higher adsorption capacity for asphaltenes. , Clays such as montmorillonite and kaolinite adsorb asphaltenes preferentially to other surfaces, making pores of mineral clays more prone to pore blockage due to the adsorption of asphaltene molecules. , The dissociation of aggregated asphaltenes is effective in the presence of silica and alumina nanoparticles due to the high adsorption capacity of asphaltenes on the nanoparticles’ surface. − However, the adsorption of asphaltenes on the surfaces of the nanoparticles changes their properties and performance in inhibiting asphaltene assembly. Studies on asphaltene aggregation in confinement are scarce, and the effect of pore size, chemistry, the presence of multiphase interfaces, and aggregation inhibitors in confinement are among the knowledge gaps in this topic.…”

Investigating the Performance of Carboxylate-Alumoxane Nanoparticles as a Novel Chemically Functionalized Inhibitor on Asphaltene Precipitation

“…Recently, nanotechnology has drawn the researchers’ attention as a novel method to tackle the asphaltene precipitation problems. − Due to appealing characteristics such as small size, high specific surface area, appreciable dispersibility in liquid media, and high adsorption capacity, the utilization of nanoparticles can be considered as an effective method for inhibiting the asphaltene aggregation. , Nassar et al studied the impact of the acidic–basic characteristics of alumina nanoparticles on asphaltene adsorption. By investigating these characteristics, they realized that the acidic, basic, and neutral alumina nanoparticles exhibit a definite tendency for asphaltene adsorption.…”