79 To What Extent Could Methanol , Toluene and Gas condensate effect on Heavy crude oil viscosity reduction , Sheikhan oil field , Case Study

corresponding Author: ahmedeng1986@yahoo.com


The existence of high viscous heavy crude oil in high amount in Kurdistan/ Iraq reservoir attract the petroleum companies to extract and produce it. The heavy crude oil is a complex fluid with viscosity higher than the conventional oil. Where the viscosity of this type of oil is (greater than 10000 c.p) and the specific gravity is between (10-20) API. These two physical factors effect negatively on the crude oil mobility in both in-situ and surface condition.

High viscous heavy crude oil faces difficulties during separation and transportation from production sites to processing facilities. One of the solutions to enhance the flow rate is reducing the viscosity by using chemical solvents and gas condensate.

Since the asphaltenes are the main component of heavy crude oil; therefore, it plays a significant role to increase the viscosity of heavy oil. As a result, making any modification in structure of asphaltene aggregates leads to oil viscosity alteration. For this purpose, a heavy crude oil sample from Sheikhan oilfield was blended with different concentration rate of solvents (toluene, methanol) and gas condensate in order to justify the structure of asphaltene content and understand how this effect on heavy crude oil viscosity.

Hawbash kh. Mahmood et al /American Journal of Oil and Chemical Technologies 7 (2019) 79-93

This study shows that mixing the heavy crude oil sample with toluene have a great reduction in the crude oil viscosity since this solvent content aromatic molecules in his structure. These molecules tend to interface between asphaltenes sheets and dissociation of asphaltene aggregates.

In addition, the influence of methanol on viscosity reduction is less due to forming hydrogen bonds between asphaltene and methanol molecules. Finally, the gas condensate had a good influence on heavy crude oil viscosity reduction.

Keywords: Heavy crude oil , Viscosity reduction , Chemical Slovetns




[1] Al-Bajalan, A. R., 2015. Effect of (Iron, Nickel, Zinc and Copper) Metal Particles on Heavy oil viscosity reduction. International Journal of Advanced Scientific and Technical Research, 4(5), pp. 199-211.

[2] Amir Hossein Saeedi Dehaghani, M. H. B., 2016. Experimental study of Iranian heavy crude oil viscosity. Petroleum , Volume 2, pp. 415-424.

[3] Esmail, M. T. G. a. N., 2006. Flow Enhancement of Medium-Viscosity Crude Oil. Petroleum Science and Technology, 4(8), pp. 986-998.

[4] Gateau, P.; Hénaut, I.; Barré, L.; Argillier, J., Heavy oil dilution. Oil & gas science and technology 2004, 59, (5), 503-509.

[5] Hashemi, R.; Nassar, N. N.; Pereira Almao, P., Enhanced heavy oil recovery by in situ prepared ultradispersed multimetallic nanoparticles: A study of hot fluid flooding for Athabasca bitumen recovery. Energy & Fuels 2013, 27, (4), 2194-2201.

[6] Junaki, E., Ghanaatian, S. & Zargar, 2012. A new approach to simultaneously enhancing heavy oil recovery and hindering asphaltene precipitation.. Iranian Journal of Oil & Gas Science and Technology, 1(1), pp. 37-42.

[7] Martinez-Palou, R. et al., 2015. Study of the formation and breaking of extra-heavy-crude-oil- in-water emulsions—A proposed strategy for transporting extra heavy crude oils.. Chemical engineering and processing , Volume 98, pp. 112-122.

[8] Martínez-Palou, R.; de Lourdes Mosqueira, M.; Zapata-Rendón, B.; Mar-Juárez, E.; Bernal- Huicochea, C.; de la Cruz Clavel-López, J.; Aburto, J., Transportation of heavy and extra-heavy crude oil by pipeline: A review. Journal of Petroleum Science and Engineering 2011, 75, (3), 274- 278

[9] Peng Luo, C. Y. ,. Y. G., 2007. Enhanced solvent dissolution into in-situ upgraded. Fluid Phase Equilibria, pp. 143-151.


Hawbash kh. Mahmood et al /American Journal of Oil and Chemical Technologies 7 (2019) 79-93

[10] Rafael Martínez-Palou a, M. d. L. M. ,. B. Z.-R. ,. E. M.-J. ,., 2011. Transportation of heavy and extra-heavy crude oil by pipeline: A review. Journal of Petroleum Science and Engineering , Volume 75, pp. 274-282.

[11] Santos, I. C. V. M., Oliveira, P. F. & Mansur, C. R. E. 1., 2017. FACTORS THAT AFFECT CRUDE OIL VISCOSITY AND TECHNIQUES TO REDUCE IT: A REVIEW. Barazilian Journal of Oil and Gas , 11(2), pp. 115-130.

[12] Shadi W. Hasan, M. T. G. ,. N. E., 2010. Heavy crude oil viscosity reduction and rheology for pipeline transportation. FUEL, Issue 89, pp. 1095-1100.

[13] Xie, H., Zhang, F. & Dong, L., 2001. Study and application of the viscosity reducer used in production of the viscous crude oi. SPE International Symposium on Oilfield Chemistry.

[14] Urquhart, R., Heavy oil transportation-present and future. Journal of Canadian Petroleum Technology 1986, 25, (02).

[15] Khan, M. R. 1996. Rheological properties of heavy oils and heavy oil emulsions. Energy Sources 18:385