Título: | ASSESSMENT OF MOLECULAR DIFFUSION AS A MECHANISM FOR WAX DEPOSITION IN PETROLEUM PIPELINES | ||||||||||||||||||||||||||||||||||||
Autor: |
MAO ILICH ROMERO VELASQUEZ |
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Colaborador(es): |
ANGELA OURIVIO NIECKELE - Orientador LUIS FERNANDO ALZUGUIR AZEVEDO - Coorientador |
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Catalogação: | 03/ABR/2006 | Língua(s): | PORTUGUESE - BRAZIL |
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Tipo: | TEXT | Subtipo: | THESIS | ||||||||||||||||||||||||||||||||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=8057&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=8057&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.8057 | ||||||||||||||||||||||||||||||||||||
Resumo: | |||||||||||||||||||||||||||||||||||||
Deposition of high molecular weight para±ns on the inner
wall of subsea
production and transportation pipelines continues to be a
critical operati-
onal problem faced by the petroleum industry. The accurate
prediction of
wax deposition rates and deposited wax spatial
distribution would be an
invaluable information for the design of subsea pipelines.
A critical review
of the literature conducted lead to the conclusion that
there is not enough
experimental evidence to determine which are the more
relevant mecha-
nisms responsible for wax deposition. However, the
majority of available
simulations employ the molecular diffusion model as the
only deposition
mechanism. Therefore, in the present work, a numerical
analysis of the wax
deposition in ducts is performed employing the molecular
diffusion model
and a comparison with experimental data of a simple and
basic experiment
in a rectangular cross section duct is performed. Two
mathematical mo-
dels are investigated; the first formulation is one-
dimensional and the wax
deposition rate is determined from the temperature
gradient. The second
formulation is two-dimensional and the wax deposition rate
is a function
of the para±n concentration gradient. The finite volume
method was selec-
ted to solve the conservation equations of mass, energy
and mass fraction,
coupled with a difusive equation to describe the growth of
the wax deposi-
tion. Additionally, the influence of the para±n latent
heat was investigated.
It was verified that the latent heat accelerates the
deposition process, but
does not affect thenal wax thickness after reaching the
steady state regime.
The results obtained presented signifficant differences
between experiments
and computation, indicating that molecular diffusion might
not be the only
relevant mechanism responsible for wax deposition.
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