CORRELATION OF ASPHALTENE SOLVATION WITH STABILITY OF CRUDE OIL EMULSION USING SCALING EQUATIONS
Keywords:Crude Oil, Emulsion, Asphaltene, Solvation, Scaling equations, Bancroft’s rule
Due to the simplicity of scaling equations and its applicability to colloid chemistry, the scaling theory is widely used in studying emulsion properties such as force profiles. Scaling equations were developed for the studied samples for correlation of asphaltene solvation with stability of crude oil emulsions. Correlations were made for viscosity and percentage water resolved by varying the volume concentration of toluene in heptol mixture that was used as solvent for the asphaltene re-dissolution. The study shows that tuning the composition of heptol allows fine control of colloidal forces between asphaltene surfaces in an organic solvent and therefore determines the stability state of the emulsion. Statistically derived correlation equations provide for a range in the aromaticity of the crude medium for which an optimum stability is observed and therefore gives good understanding on the control of emulsion stability. The study further shows that emulsion inversion can be achieved by adjusting the concentration of surfactant.
Anisa, A. N. I; Nour, A. H.; Nour, Ashary H (2010): Castastrophic and Transitional Phase Inversion of water-in-oil Emulsion for Heavy and Light Crude Oil. Journal of Applied Sci., 10(23) 3076 – 3083.
Cimino, R., et al. (1995): Solubility and Phase Behavior of Asphaltenes in Hydrocarbon Media, in Asphaltenes: Fundamentals and Applications, E.Y. Sheu and O.C. Mullins, Editors. 1995, Plenum Press: New York, 97-130.
Ekott and Akpabio (2013): Understanding Asphaltene Solvation Nexus and Stability Analyses of Heavy Crude Oil Emulsions. Int. Journal of Engineering, Science and Technology. Vol.3, No. 1
Espinat, D.; Ravey, J. C.; Guille, V.; Lambard, J.; Zemb, T. and Cotton, J. P. (1993): Colloidal macrostructure of crude oil studied by neutron and X-ray small angle scattering techniques. Journal de Physique IV, (Colloque C8, supplément au Journal de Physique I), 181-184.
Hong, E. and Watkinson, P. (2004): A study of asphaltene: Solubility and Precipitation. Fuel, 83, 1881 – 1887.
Hu, Yu-Feng; Li, S; Liu, N; Chu, Y; Park, S. J.; Mansoori, G. A and Guo, T. (2004): Measurement and corresponding states modelling of asphaltene precipitation in Jilin reservoir oils. Journal of Petroleum Science and Engineering. 41(1-3), 199-221 – 242.
McLean, J. D. and Kilpatrick, P. K. (1997): Effects of asphaltene aggregation in model heptane-toluene mixtures on stability of water-in-oil emulsions. Journal of Colloid and Interface Science, 196 (1), 23-34.
Siffert, B.; Bourgeois, C. and Papirer, E. (1984): Structure and Water-Oil Emulsifying Properties of Asphaltenes. Fuel, 63 (6): p. 834-837.
Spiecker, P. M. and Kilpatrick, P. K (2004): Interfacial Rheology of Petroleum Asphaltenes at the oil-water interface. Langmuir. 20. 4022-4032.
Wang, S. (2011): Understanding Stability of Water-in-diluted Bitumen Emulsion by Colloidal Force Measurements. Ph.D. Thesis, University of Alberta, Edmonton.