NS  Vol.2 No.5 , May 2010
Wettability alteration by magnesium ion binding in heavy oil/brine/chemical/sand systems—analysis of hydration forces
In laboratory sandpack tests for heavy oil re-covery by alkaline flooding, it was found that wettability alteration of the sand had a significant impact on oil recovery. In this work, a heavy oil of 14? API was used to examine the effect of organic acids in the oil and water che- mistry on wettability alteration. From interfacial tension measurements and sand surface composition analysis, it was concluded that the water-wet sand became preferentially oil-wet by magnesium ion binding. The presence of Mg2+ in the heavy oil/Na2CO3 solution/sand system increased the oil/water interfacial tension. This confirmed the hypothesis that magnesium ion combined with the ionized organic acids to form magnesium soap at oil/water interface. Under alkaline condition, the ionized organic acids in the oil phase partition into the water phase and subsequently adsorb on the sand surfaces. The analysis of sand surface composition sugg- ested that more ionized organic acids adsorb- ed on the sand surface through magnesium ion binding. The attachment of more organic acids on the sand surface changed hydration forces, making the sand surface more oil-wet.

Cite this paper
Liu, Q. , Dong, M. , Asghari, K. and Tu, Y. (2010) Wettability alteration by magnesium ion binding in heavy oil/brine/chemical/sand systems—analysis of hydration forces. Natural Science, 2, 450-456. doi: 10.4236/ns.2010.25055.
[1]   Dullien, F.A.L. (1992) Porous media – fluid transport and pore structure, 2nd Edition. Academic Press, San Diego.

[2]   Hirasaki, G.L. (1991) Wettability: Fundamentals and surface forces. Society of Petroleum Engineering Forma-tion and Evaluation, 6(2), 217-226.

[3]   Liu, K., Eadington, P. and Coghlan, D. (2003) Fluores-cence evidence of polar hydrocarbon interaction on min-eral surfaces and implications to alteration of reservoir wettability. Journal of Petroleum Science and Engineering, 39(3-4), 275-285.

[4]   Dubey, S.T. and Waxman, M.H. (1991) Asphaltenes ad-sorption and desorption from mineral surfaces. Society of Petroleum Engineering Research, 6(1), 389-395.

[5]   Croker, M.E. and Marchin, L.M. (1988) Wettability and adsorption characteristics of crude oil asphaltenes and polar fractions. Journal of Petroleum Technology, 40(4), 470-474.

[6]   Morrow, N.R., Cram, P.J. and McCaffery, F.G. (1973) Displacement studies in dolomite with wettability control by octanoic acid. Society of Petroleum Engineering Jour- nal, 13(4), 221-232.

[7]   Collins, S.H. and Melrose, J.C. (1983) Adsorption of asphaltenes and water on reservoir rock minerals. Pro-ceedings of the SPE International Symposium on Oilfield and Geothermal Chemistry, 11800, Denver.

[8]   Kaminsky, R. and Radke, C.J. (1998) Water films, as-phaltenes, and wettablity alteration. SPE/DOE Symposium on Improved Oil Recovery, 39087, Tulsa.

[9]   Kowalewski, E., Holt, T. and Torsaeter, O. (2002) Wetta-bility alterations due to an oil additive. Journal of Petro-leum Sciences and Engineering, 33(1-3), 19-28.

[10]   Ashayer, R., Grattoni, C.A. and Luckham, P.F. (2000) Wettability changes during surfactant flooding. 6th In-ternational Symposium on Evaluation of Reservoir Wet-tability and its Effect on Oil Recovery, Socotrro.

[11]   Buckley, J.S., Liu, Y. and Monsterleet, S. (1998) Me-chanisms of wetting alteration by crude oils. Society of Petroleum Engineering Journal, 3(1), 54-61.

[12]   Cooke, Jr.C.E., William, R.E. and Kolodzie, P.A. (1974) Oil recovery by alkaline waterflooding. Journal of Pe-troleum Technology, 26(12), 1365-1374.

[13]   Miller, K.A. (2005) State of the art of western Canadian heavy oil water flood technology. Proceedings of Petro-leum Society’s 6th International Petroleum Conference (56th Annual Technical Meeting), 2005-251, Calgary.

[14]   Ma, S., Dong, M., Li, Z. and Shirif, E. (2007) Evaluation of effectiveness of chemical flooding using heterogeneous sandpack flood test. Journal of Petroleum Science and Engineering, 55(3-4), 219-228.

[15]   Liu, Q., Dong, M., Asghari, K. and Tu, Y. (2007) Wetta-bility alteration by magnesium ion binding in heavy oil/brine/chemical/sand systems-Analysis of electrostatic forces. Journal of Petroleum Science and Engineering, 59(1-2), 147-156.

[16]   Dong, M., Foraie, J., Huang, S. and Chatzis, I. (2005) Analysis of immiscible water-alternating-gas (WAG) in-jection using micromodel. Journal Canadian Petroleum Technology, 44(2), 17-25.

[17]   ASTM (1989), Standard test method for synthetic anionic ingredient by cationic titration. Annual Book of ASTM Standards, American Society for Testing and Materials, West Conshohocken, 15(4), 320-323