A Study of the Colloidal Characteristics of Petroleum using the Ultracentrifuge

Ray, B. Roger; Witherspoon, P.A.; Grim, Ralph E.

doi:10.1021/j150556a009

Cited by 99 publications

(46 citation statements)

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“…According to Figures 2 & 3, it is also observed that when Abkatun-93 and Pol-73 crudes were submitted separately to the test the amount of deposits reached the lowest value at 50"C, where the vol% of sediments is less than 0.3% at all test conditions. Although sizable amounts of sediments were observed in these experiments, the deposits cannot be thought to be comprised of asphaltenes, considering the fact that in order to separate asphaltenes from a live crude oil one needs to use ultracentrifuge with angular velocities in the range of 30,000-80,000 rpm and for a duration of about 9 days [19]. Therefore, we conclude the sediments observed are primarily due to paraffin/wax precipitation.…”

Section: Heavy Organic Deposition In the Campeche Marine Platformmentioning

confidence: 70%

Heavy Organic Deposition and Plugging of Wells (Analysis of Mexico's Experience)

Escobedo

Mansoori

1992

Proceedings of SPE Latin America Petroleum Engineering Conference

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The pipeline transportation of petroleum fluids can be significantly affected by flocculation, deposition, and plugging of asphaItene, paraffin/wax, and/or diamondoid in the transfer pipelines, tubulars, pumps, and other equipment. The economic implications of the problem of heavy organic depositions in such processes are tremendous.In this report Mexico's experience with the pipeline plugging due to heavy organic deposition is reviewed and analysed based on the present state of knowledge. The modeling basis of a comprehensive estimation and prediction technique is presented. This technique is based on observed field and laboratory data, statistical mechanical theories, polydisperse polymer solution theory, continuous thermodynamics, electrokinetics and transport phenomena, colloidal solution theory, and the FRACTAL aggregation theory. INTRODUCTIONA number of problems could arise during the production of petroleum which would drastically increase the production costs.

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Section: Heavy Organic Deposition In the Campeche Marine Platformmentioning

confidence: 70%

Heavy Organic Deposition and Plugging of Wells (Analysis of Mexico's Experience)

Escobedo

Mansoori

1992

Proceedings of SPE Latin America Petroleum Engineering Conference

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“…The molar volume was assumed to be temperatureindependent and was estimated from in which Pa was taken to be 1,200 kg/m 3 [75 lbm/ft 3 ]. 7 We assume asphalt properties to be independent of pressure.…”

Section: Discussionmentioning

confidence: 99%

“…The effective asphalt volume fraction, c/Je, is related to the actual volume fraction, c/Ja, by c/Ja c/Je=--, · · · · · · .·. · · · · · · · · · · · · · ................. (7) c/Jmax where c/Jmax corresponds to the concentration of asphalt for which the oil viscosity becomes infinite. From Yen 9 and Reerink' s 12 data on the shape of asphaltene molecules assuming that an asphalt is about two associated asphaltene sheets (Appendix B) and from the viscosity data of Reerink, Altgelt and Harle 14 and Ronvaux-Vankeerbergen et al, 15 we conclude that a reasonable estimate for c/Jmax is 0.28.…”

Section: Consequences Of Asphalt Segregationmentioning

confidence: 99%

Role of Asphaltenes in Compositional Grading of a Reservoir's Fluid Column

Hirschberg¹

1988

Journal of Petroleum Technology

109

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The relationship between compositional variations induced by gravity and reservoir-fluid phase behavior has been investigated. In light oils (stock-tank oil gravity ::::;0.85 g/cm 3 [2=:35°API]), strong compositional grading will occur if the reservoir fluid is near critical. In heavier oils, compositional grading is caused by the segregation of asphaltenes, resulting in variation in oil viscosity and the possibility of tar-mat formation.

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“…Details of the manner in which these data were obtained and treated are beyond the scope of this review and are presented elsewhere. [26][27][28][29][30][31][32][33][34][35][36] Winniforda5 obtained similar results when he used the ultracentrifuge approach to study asphaltenes that were separated from several air-blown and steam-refined asphalts. He has further refined this approach by pointing out that the asphaltene particles are solvated, and that after the effects of solvation are taken into account, the molecular weights will be higher than when this factor is ignored.…”

Section: Ultracentrifuge Investigationsmentioning

confidence: 97%