Sedimentation-induced burial of subsea pipelines: Observations from field data and laboratory experiments

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

© 2016 Elsevier B.V. Sediment transport-induced changes to the embedment of three 26 km long sections of subsea pipeline are analysed and subsequently explained using model scale experiments. Rather than the scour and scour-induced sinking and sagging traditionally thought to dominate post-lay pipeline spanning and embedment change, the change for these pipelines is shown to be caused by sedimentation. The pipelines traverse a range of metocean and soil conditions; the variation in embedment correlates well with the variation in metocean conditions, with most change occurring in an area where multidirectional high-velocity short-duration flows associated with internal waves propagate at near-perpendicular angles to the pipeline. To understand the mechanism driving these changes, a series of model scale tests in O-tube flumes have been completed under flow conditions mimicking those recorded in the field. Good agreement is found between the field and laboratory results, both in terms of the process timescale and the post-sedimentation profile. The consistency of the embedment changes between the pipelines, their correlation with metocean conditions, and the ability to replicate these changes in model scale tests suggests that such changes can be accounted for in more effective pipeline design. Spans are relatively rare along the pipelines but where they do occur fish rather than scour are shown to be the principal agent of span formation.
Original languageEnglish
Pages (from-to)137-158
JournalCoastal Engineering
Volume114
DOIs
Publication statusPublished - 2016

Fingerprint

Sedimentation
Pipelines
Scour
Experiments
Sediment transport
Fish
Soils

Cite this

@article{9fb7e89e264f4415bc9596fd3a442fac,
title = "Sedimentation-induced burial of subsea pipelines: Observations from field data and laboratory experiments",
abstract = "{\circledC} 2016 Elsevier B.V. Sediment transport-induced changes to the embedment of three 26 km long sections of subsea pipeline are analysed and subsequently explained using model scale experiments. Rather than the scour and scour-induced sinking and sagging traditionally thought to dominate post-lay pipeline spanning and embedment change, the change for these pipelines is shown to be caused by sedimentation. The pipelines traverse a range of metocean and soil conditions; the variation in embedment correlates well with the variation in metocean conditions, with most change occurring in an area where multidirectional high-velocity short-duration flows associated with internal waves propagate at near-perpendicular angles to the pipeline. To understand the mechanism driving these changes, a series of model scale tests in O-tube flumes have been completed under flow conditions mimicking those recorded in the field. Good agreement is found between the field and laboratory results, both in terms of the process timescale and the post-sedimentation profile. The consistency of the embedment changes between the pipelines, their correlation with metocean conditions, and the ability to replicate these changes in model scale tests suggests that such changes can be accounted for in more effective pipeline design. Spans are relatively rare along the pipelines but where they do occur fish rather than scour are shown to be the principal agent of span formation.",
author = "Simon Leckie and Henning Mohr and Scott Draper and Dianne Mclean and David White and Liang Cheng",
year = "2016",
doi = "10.1016/j.coastaleng.2016.04.017",
language = "English",
volume = "114",
pages = "137--158",
journal = "Coastal Engineering",
issn = "0378-3839",
publisher = "Elsevier",

}

TY - JOUR

T1 - Sedimentation-induced burial of subsea pipelines: Observations from field data and laboratory experiments

AU - Leckie, Simon

AU - Mohr, Henning

AU - Draper, Scott

AU - Mclean, Dianne

AU - White, David

AU - Cheng, Liang

PY - 2016

Y1 - 2016

N2 - © 2016 Elsevier B.V. Sediment transport-induced changes to the embedment of three 26 km long sections of subsea pipeline are analysed and subsequently explained using model scale experiments. Rather than the scour and scour-induced sinking and sagging traditionally thought to dominate post-lay pipeline spanning and embedment change, the change for these pipelines is shown to be caused by sedimentation. The pipelines traverse a range of metocean and soil conditions; the variation in embedment correlates well with the variation in metocean conditions, with most change occurring in an area where multidirectional high-velocity short-duration flows associated with internal waves propagate at near-perpendicular angles to the pipeline. To understand the mechanism driving these changes, a series of model scale tests in O-tube flumes have been completed under flow conditions mimicking those recorded in the field. Good agreement is found between the field and laboratory results, both in terms of the process timescale and the post-sedimentation profile. The consistency of the embedment changes between the pipelines, their correlation with metocean conditions, and the ability to replicate these changes in model scale tests suggests that such changes can be accounted for in more effective pipeline design. Spans are relatively rare along the pipelines but where they do occur fish rather than scour are shown to be the principal agent of span formation.

AB - © 2016 Elsevier B.V. Sediment transport-induced changes to the embedment of three 26 km long sections of subsea pipeline are analysed and subsequently explained using model scale experiments. Rather than the scour and scour-induced sinking and sagging traditionally thought to dominate post-lay pipeline spanning and embedment change, the change for these pipelines is shown to be caused by sedimentation. The pipelines traverse a range of metocean and soil conditions; the variation in embedment correlates well with the variation in metocean conditions, with most change occurring in an area where multidirectional high-velocity short-duration flows associated with internal waves propagate at near-perpendicular angles to the pipeline. To understand the mechanism driving these changes, a series of model scale tests in O-tube flumes have been completed under flow conditions mimicking those recorded in the field. Good agreement is found between the field and laboratory results, both in terms of the process timescale and the post-sedimentation profile. The consistency of the embedment changes between the pipelines, their correlation with metocean conditions, and the ability to replicate these changes in model scale tests suggests that such changes can be accounted for in more effective pipeline design. Spans are relatively rare along the pipelines but where they do occur fish rather than scour are shown to be the principal agent of span formation.

U2 - 10.1016/j.coastaleng.2016.04.017

DO - 10.1016/j.coastaleng.2016.04.017

M3 - Article

VL - 114

SP - 137

EP - 158

JO - Coastal Engineering

JF - Coastal Engineering

SN - 0378-3839

ER -