A Novel Method for Mitigation of Asphaltene Deposition in the Wellstring

Document Type: Research Article

Authors

1 Faculty of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11365-8639 Tehran, I.R. IRAN

2 Institute of Petroleum Engineering, Heriot-Watt University, Edinburgh EH14 4AS, UNITED KINGDOM

3 Petroleum University of Technology, PO Box: 63431 Ahwaz, I.R. IRAN

Abstract

Asphaltene precipitation and deposition is a serious problem in many Iranian fields. The deposited asphaltene results in partial or total blockage of the wellbore and wellstring reducing or completely seizing oil production. This paper studies the asphaltene problem and mitigation methods in wellstring systematically. It presents new approach based on the combination of thermodynamic modeling of asphaltene precipitation with hydrodynamic well modeling. The developed model is capable to determine the asphaltene precipitation and deposition interval through the wellstring. Therefore, it could study the effect of hydrodynamic parameters such as wellhead pressure, well flow-rate and tubing size on the mitigation of asphaltene deposition. The conventional way to treat asphaltene deposition was through remediation which attacks the problem after it occurs. This model is capable to determine the severity of asphaltene deposition even before start of production. The model was applied to simulate the asphaltene precipitation in one of the south Iranian oil fields (Kupal) and important guidelines have been studied to mitigate the risks associated with asphaltene deposition. The results of modeling show that change in hydrodynamic condition could reduce and mitigate asphaltene deposition damage. But in some cases it would not be possible to prevent asphaltene precipitation completely. Therefore, the approach for flow assurance in those cases would be to change the well completion and inject asphaltene inhibitor, in order to prevent deposition of asphaltene flocculates.  

Keywords

Main Subjects


[1] Leontaritis K.J., Mansoori G.A., Asphaltene Flocculation During Oil Production and Processing: A Thermodynamic Colloidal Model, SPE 16258 (1987).
[2] Civan F., Reservoir Formation Damage, Gulf Publication, Burlington, pp. 468-477 (2007).
[3] Bunger J.W., Li N.C., "Chemistry of Asphaltene", P.195, Amer. Chemical Society, Washington(1982).
[4] Khalil C.N., Rocha N.O., Silva E.B., Detection of Formation Damage Associated to Paraffin in Researvoir of the Reconcavo Baiano, Brazil, SPE 37238, (1997).
[5] Allenson S.J., Walsh M.A, A Novel Way to Treat Asphaltene Depositoin Problems Found in Oil Production, SPE 37286 (1997).
[6] Haskett C.E., Tartera M.,A., Practical Solution to the Problem of Asphaltene Deposits-Hassi Messoud Field, Algeria, Pet. Eng. J., 387 (1965).
[7]Thawer R., Nicoll D.C.A., Graeme D.,Asphaltene Deposition in Production Facilities, Soc. Pet. Eng. J., 475 (1990).
[8] Alkafeef S.F., Al-Medhadi F., Al-Shammari A., A Simplified Method to Predict and Prevent Asphaltene Deposition in Oil Well Tubings: Field Case, Soc. Pet. Eng. J., 126 (2005).
[9] Soulgani B.S., Tohidi B., Rashtchian D., Jamialahmadi M., Modeling of Asphltene Precipitation in Well Column of Iranian Crudes: Kupal Case Study, Can. Int. Pet. Conf., (2008).
[10] Begges H.D., Brill J.P., A Study of Two-Phase Flow in Inclined Pipes, J.  Pet. Tech., 607 (1973).
[11] Hirschberg A., De Jong L.N.J., Schipper B.A., Meyers J.G., Influence of Temperature and Pressure on Asphaltene Flocculation, Soc. Pet. Eng. J.,24,(3), 283(1984).
[12] Boer R.B., Leerlooyer K., Elgner M.R.P., van Bergen A.R.D., Screening of Crude Oil for Asphalt Precipitation: Theory, Practice, and the Selection of Inhibitors, Soc. Pet. Eng. J., 10,(2), 55 (1995)
[13] Nghiem L.X., Coombe D.A., Ali F., Compositional Simulation of Asphaltene Deposition and Plugging, SPE 48996 (1998).
[14] Zhou X., Thomas F.B., Moore R.G., Modeling of Solid Precipitation from Reservoir Oil, J. Can. Pet. Tech., 35(10), 37 (1996).
[15] Jamaluddin  A.K.M,  Nigheswander  J., Joshi  N., D. Calder D., Ross B., Asphaltenes Characterization: A Key to Deepwater Developments, SPE 77936 (2002).
[16] Leontaritis K.J., Mansoori G.A., Asphaltene Flocculation During Oil Production and Processing: A Thermodynamic Colloidal Mode, SPE 16258 (1987).
[17] Rassamdana H., Dabir B., Nematy M., Farhani M., Sahimi M., Asphalte Flocculation and Deposition: I.The Onset of Precipitation, AIChE J., 42, (1),10 (1996).
[18] Hu Y.F.,  Chen G.J.,  Yang J.T.,  Guo T.M., A Study on the Application of Scale Equation for Asphaltene Precipitation, Fluid Phase Equilibria, 171, p. 181 (2000).
[19] Hong E., Watkinsom P., A Study of Asphaltene Solubility and Precipitation, Fuel., 83, 1881 (2004).
[20] Ashoori S., PhD thesis, Department of Chemical and Process Engineering. University o fSurrey, Guildford, UK. (2005)
[21] Rassamdana M., Farhani M., Dabir B., Mozaffarian, M., Sahimi M., Asphalt Flocculation and Deposition. V. Phase Behavior in Miscible and Immiscible Injection, Energy &Fuels. 13, (1), p. 176 (1999).
[22] Hu Y.F., Guo T.M., Effect of Temperature and Molecular Weight of N-Alkane Precipitants on Asphaltene Precipitation, Fluid Phase Equiliria, 192, (1), 13 (2001).
[23] Burke N.E., HobbsR.E., Kashou, S.F., Measurement and Modeling of Asphaltene Precipitation, J. Pet. Tech,1440, p. 145 (1990).
[24] Jamaluddin, A.K.M., Kabir, C.S., McFadden, J.D., D’Cruz, D., Joseph, M.T., Joshi N., Ross, A Comparison of Various Laboratory Techniques to Measure Thermodynamic Asphaltene Instability, SPE 72154 (2001).
[25] Brill J.P., Mukhrejee H., Multiphase Flow in Well, Soc. Pet. Eng.Texas, P.41-47 (1999).
[26] Sagar R.,  Doty D.R.,  Schmidt Z., Predicting Temperature Profiles in a Flowing Well,  SPE 19702 (1991).
[27] Mansoori G.A., Modeling of Asphaltenes and Other Heavy Oranics Deposition, J. Pet. Sci. Tech., 17,
p. 101 (1997).