Experimental study of improving Nigerian heavy crude oil (Agbabu bitumen) viscosity reduction by dilution with n-heptane, phenol, toluene, xylene, and naphtha
DOI:
https://doi.org/10.53704/Keywords:
Viscosity, Heavy Oil, Solvent, Dynamic, KinematicAbstract
This experimental study examines the viscosity reduction of Nigerian heavy crude oil, specifically Agbabu bitumen, through dilution with selected solvents, including naphtha, n-heptane, phenol, toluene, and xylene. The influence of pressure variation on the solubility-driven reduction of viscosity was investigated. Solubility tests of bitumen in each solvent were conducted at pressures of 20, 80, 140, 200, and 260 psia. The results indicate that bitumen solubility increases with pressure across all solvents, with xylene exhibiting the highest solubility, 13.0 mol/dm³, at 260 psia. Kinematic and dynamic viscosities were measured using a Redwood viscometer under minimum- and maximum-solubility conditions. Xylene achieved the highest viscosity reduction, with dynamic viscosity decreasing from 390.6 cP to 13.95 cP and kinematic viscosity reducing from 420 cSt to 15.0 cSt. The study highlights the superiority of aromatic solvents in reducing the viscosity of Agbabu bitumen, providing insights useful for heavy crude oil production and transportation. The findings of this study contribute to the development of cost-effective, efficient approaches to enhancing the production and transportation of heavy crude oil. The results also provide valuable insights into the thermodynamic and rheological behaviour of heavy oil-solvent mixtures under varying pressure conditions. This study's results can be applied to optimise the design and operation of heavy oil production and transportation systems, ultimately improving the economic viability of heavy oil resources.
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Copyright (c) 2026 Adetokunbo A. Falade, O. O Akinsete, H. O Aliu,, Olawole Mobolaji, Temitope Oni
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