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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Heat and Mass Transfer in Wax Deposition in Pipelines

Get access (open in a dialog) DOI: 10.1615/IHTC15.kn.000004
pages 62-81

Abstract

Wax deposition continues to be a critical operational problem in crude oil pipelines operating in cold environments. Therefore, accurate prediction of wax deposition rates and deposited wax spatial distribution is invaluable information for the design of subsea lines. Unfortunately, wax deposition is a complex process for which the mechanisms are still not fully understood. The present paper is part of an ongoing research effort directed at identifying the relative importance of the mechanisms responsible for paraffin deposition. The research program encompasses experiments at the laboratory scale and numerical simulations. The experiments employ test sections with simple geometries with well-defined and controlled boundary and initial conditions, using simple oil-paraffin laboratory solutions, and with known transport properties. The results obtained from these controlled experiments are then compared to numerical simulations that try to faithfully reproduce the experimental conditions. Contrary to the experimental studies, the simulations studies permit that different models proposed for deposition mentioned in the literature can be tested individually, allowing, thereby, an assessment of the relative importance of each of the deposition mechanisms. The present paper focus on the comparison of measured and predicted laminar and turbulent deposition data obtained under controlled conditions with numerical simulations of the conservation equations of mass, momentum, energy and concentration. Based on the experimental evidences, different deposition models were investigated. All models predicted the same deposit thickness at steady state with a reasonable agreement with experimental data. However, the transient evolution of the deposit was not well capture, indicating that the deposition mechanisms proposed in the literature still do not proper represent the phenomenon.