Subsea pipeline walking with velocity dependent seabed friction
Subsea pipeline walking with velocity dependent seabed friction
With the increase in demand and supply gap in the oil and gas industry, new developments of oil and gasinfrastructure are moving into deeper water. This requires design and construction of long high temperature and high pressure pipelines from deep sea to shore. These pipelines are subjected to cyclic expansion during operating cycles. Accumulated axial movement due to repeated thermal cycles may lead to global displacement referred to as ‘walking’. Walking rates depend on the restraint associated with seabed friction. In conventional analyses, seabed friction is independent of the rate of thermal loading and expansion but it has been recognised that the sliding resistance between a pipe and the seabed varies with velocity, partly due to drainage effects. In this paper a numerical model is used to explore the effect of velocity-dependent seabed friction. A velocity-dependent friction model is implemented in commercial software ABAQUS and validated via single element and simple (flat seabed) pipeline cases. This model features upper and lower friction limits, with a transition that occurs as an exponential function of velocity. A parametric study is performed using differing rates of heating and cool-down in walking situations driven by seabed slope, SCR end tension and the difference between heat up and cool down rates. The walking behaviour is compared to cases with constant friction and solutions are proposed to express the velocity-dependent response in terms of an equivalent constant friction. These equivalent friction values can then be applied in existing simple solutions or more complex numerical analyses, as a short cut method to account for velocity-dependent friction.
Subsea pipelines, Velocity dependent seabed friction, Walking
296-308
Guha, Indranil
1ba88002-5df6-4ece-a7a1-312cf699fac0
White, David J.
a986033d-d26d-4419-a3f3-20dc54efce93
Randolph, Mark F.
75caa33a-e630-4ae8-84cd-758797bf9633
1 January 2019
Guha, Indranil
1ba88002-5df6-4ece-a7a1-312cf699fac0
White, David J.
a986033d-d26d-4419-a3f3-20dc54efce93
Randolph, Mark F.
75caa33a-e630-4ae8-84cd-758797bf9633
Guha, Indranil, White, David J. and Randolph, Mark F.
(2019)
Subsea pipeline walking with velocity dependent seabed friction.
Applied Ocean Research, 82, .
(doi:10.1016/j.apor.2018.10.028).
Abstract
With the increase in demand and supply gap in the oil and gas industry, new developments of oil and gasinfrastructure are moving into deeper water. This requires design and construction of long high temperature and high pressure pipelines from deep sea to shore. These pipelines are subjected to cyclic expansion during operating cycles. Accumulated axial movement due to repeated thermal cycles may lead to global displacement referred to as ‘walking’. Walking rates depend on the restraint associated with seabed friction. In conventional analyses, seabed friction is independent of the rate of thermal loading and expansion but it has been recognised that the sliding resistance between a pipe and the seabed varies with velocity, partly due to drainage effects. In this paper a numerical model is used to explore the effect of velocity-dependent seabed friction. A velocity-dependent friction model is implemented in commercial software ABAQUS and validated via single element and simple (flat seabed) pipeline cases. This model features upper and lower friction limits, with a transition that occurs as an exponential function of velocity. A parametric study is performed using differing rates of heating and cool-down in walking situations driven by seabed slope, SCR end tension and the difference between heat up and cool down rates. The walking behaviour is compared to cases with constant friction and solutions are proposed to express the velocity-dependent response in terms of an equivalent constant friction. These equivalent friction values can then be applied in existing simple solutions or more complex numerical analyses, as a short cut method to account for velocity-dependent friction.
Text
Guha et al 2018 AM
- Accepted Manuscript
More information
Accepted/In Press date: 30 October 2018
e-pub ahead of print date: 22 November 2018
Published date: 1 January 2019
Keywords:
Subsea pipelines, Velocity dependent seabed friction, Walking
Identifiers
Local EPrints ID: 426827
URI: http://eprints.soton.ac.uk/id/eprint/426827
ISSN: 0141-1187
PURE UUID: 5e365e4c-b549-44b4-990c-a63988bbdf0c
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Date deposited: 13 Dec 2018 10:36
Last modified: 18 Mar 2024 05:21
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Contributors
Author:
Indranil Guha
Author:
Mark F. Randolph
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