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ISSN Online: 2377-424X

ISBN Print: 0-89116-130-9

International Heat Transfer Conference 6
August, 7-11, 1978, Toronto, Canada

TRANSIENT TEMPERATURE EEEECTS IN PREDICTING START-UP CHARACTERISTICS OF GELLING-TYPE CRUDE OILS

Get access (open in a dialog) DOI: 10.1615/IHTC6.4050
pages 67-71

Resumo

Problems related to start-up of pipelines carrying gelling-type crude oils in the Canadian Arctic are particularly challenging because of low temperatures and difficult accessibility.

Rheological studies showed that below -6.7°C, a test oil began tc gel due to crystallization of a solid phase. The gelled oil exhibited a yield stress which showed a strong dependence on the technique employed as well as on temperature.

Transient heat transfer from a pipeline containing the waxy test oil has been studied under no-flow conditions. Centre-line, mid-radius and pipe wall temperatures were measured in a section of 30.5 cm diameter pipe insulated with glass fibre. A model that assumed simple Newtonian cooling with complete mixing in the oil phase down to the gelling temperature and solid body conduction below this temperature was found to predict the measured cooling curves well, with experimental data and model being in good agreement at the centre-line and half-radius positions, while at the pipe wall (where the assumptions of the model are least valid) fair correlation was obtained.

Some estimates of allowable shut-down time are made based on the measurements of yield stress and the heat transfer model.