Study of asphaltene deposition in wellbores during turbulent flow

Abstract

Abstract During petroleum production, asphaltene particles can precipitate from the crude oil due to pressure, temperature, and composition changes along the fluid path from the reservoir to the surface. Once precipitated, those particles can deposit in the inner surface of production tubings, restricting the available flow area and reducing flow rates. To enable a better understanding of that complex mass transfer problem, a new methodology was proposed in this paper. The methodology involved a comprehensive review of fundamental concepts of the mass transfer and particle deposition theories, placing the asphaltene deposition within a more general context of particle deposition during turbulent flow. Six published particle deposition models ( Lin et al., 1953 . Ind. Eng. Chem. 45 (3), 636–640. 〈http://dx.doi.org/10.1021/ie50519a048〉; Friedlander and Johnstone, 1957. Ind. Eng. Chem. 49 (7), 1151–1956. 〈http://dx.doi.org/10.1021/ie50571a039〉; Beal, 1970. Nucl. Sci. Eng. 40, 1–11; El-Shobokshy and Ismail, 1980. Atmos. Environ. 14 (3), 297–304. 〈http://dx.doi.org/10.1016/0004-6981(80)90063-3〉; Papavergos and Hedley, 1984. Chem. Eng. Res. Des. 62, 275–295.; Escobedo and Mansoori, 1995 . Paper SPE 29488 presented at the SPE Production Operations Symposium, Oklahoma City, Oklahoma, 2–4 April. 〈http://dx.doi.org/10.2118/29488-MS〉) were studied and validated with four published aerosol experimental data sets (Friedlander, 1954. Deposition of Aerosol Particles from Turbulent Gases. Ph.D. Dissertation, University of Illinois, Urbana, Illinois (July 1954); Wells and Chamberlain, 1967. Br. J. Appl. Phys. 18, 1793–1799. 〈 http://dx.doi.org/10.1088/0508-3443/18/12/317 〉; Liu and Agarwal, 1974. J. Aerosol Sci. 5 (2), 145–155. 〈 http://dx.doi.org/10.1016/0021-8502(74)90046-9 〉; Agarwal, 1975. Aerosol Sampling and Transport. Ph.D. Dissertation. University of Minnesota, Minneapolis, Minnesota (June 1975)). Based on the results of the study, Beal’s (1970. Nucl. Sci. Eng. 40, 1–11) model was selected as the most suitable to predict particle deposition and was considered adequate also to predict asphaltene deposition (limiting its application to similar ranges of Reynolds numbers, Schmidt numbers and dimensionless relaxation times in relation to those covered in the validation study). Finally, that model was applied in a sensitivity analysis to evaluate the most important parameters and transport mechanisms governing asphaltene deposition in wellbores.