Hydrodynamic forces on near-bed small diameter cables and pipelines in currents, waves and combined flow

Terry Griffiths, Yunfei Teng, Liang Cheng, Hongwei An, Scott Draper, Henning Mohr, Antonino Fogliani, Alessio Mariani, David White

Research output: Chapter in Book/Conference paperConference paper

Abstract

The on-bottom stability design of subsea pipelines and cables is important to ensure safety and reliability but can be challenging to achieve, particularly for renewable energy projects which are preferentially located in high energy metocean environments. Often these conditions lead to the seabed being stripped of all loose sediment, leaving the cables to rest on exposed bedrock where roughness features can be similar in size to the cables. As offshore renewable energy projects progress from concept demonstration to commercial-scale developments, new approaches are needed to capture the relevant physics for small diameter cables on rocky seabeds to reduce the costs and risks of export power transmission and increase operational reliability. These same considerations also apply to the cables and small diameter pipes – such as umbilicals – required by oil and gas projects located on rocky seabeds. Recent experimental testing using the University of Western Australia's unique Large O-tube has enabled the experimental measurement of hydrodynamic forces on small diameter cables and pipes in proximity to smooth and rough beds. The tested conditions extend well beyond the existing published parameter range including much higher KC conditions together with seabed roughness which is comparable in size to the diameter. The results provide design data of great relevance to the ongoing development of marine renewable and conventional oil and gas projects, especially on rocky seabeds. This paper presents a summary of the existing knowledge on the subject as a preface to preliminary test results and gives tentative conclusions on the likely outcomes from this work.

Original languageEnglish
Title of host publicationPipelines, Risers, and Subsea Systems
Place of PublicationUK
PublisherThe American Society of Mechanical Engineers (ASME)
ISBN (Electronic)9780791858813
DOIs
Publication statusPublished - 1 Jan 2019
EventASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2019 - Glasgow, United Kingdom
Duration: 9 Jun 201914 Jun 2019

Publication series

NameProceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE
Volume5B-2019

Conference

ConferenceASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2019
CountryUnited Kingdom
CityGlasgow
Period9/06/1914/06/19

Fingerprint

Cables
Hydrodynamics
Pipelines
Surface roughness
Pipe
Power transmission
Gases
Sediments
Demonstrations
Physics
Testing
Costs
Oils

Cite this

Griffiths, T., Teng, Y., Cheng, L., An, H., Draper, S., Mohr, H., ... White, D. (2019). Hydrodynamic forces on near-bed small diameter cables and pipelines in currents, waves and combined flow. In Pipelines, Risers, and Subsea Systems (Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE; Vol. 5B-2019). UK: The American Society of Mechanical Engineers (ASME). https://doi.org/10.1115/OMAE2019-95557
Griffiths, Terry ; Teng, Yunfei ; Cheng, Liang ; An, Hongwei ; Draper, Scott ; Mohr, Henning ; Fogliani, Antonino ; Mariani, Alessio ; White, David. / Hydrodynamic forces on near-bed small diameter cables and pipelines in currents, waves and combined flow. Pipelines, Risers, and Subsea Systems. UK : The American Society of Mechanical Engineers (ASME), 2019. (Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE).
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abstract = "The on-bottom stability design of subsea pipelines and cables is important to ensure safety and reliability but can be challenging to achieve, particularly for renewable energy projects which are preferentially located in high energy metocean environments. Often these conditions lead to the seabed being stripped of all loose sediment, leaving the cables to rest on exposed bedrock where roughness features can be similar in size to the cables. As offshore renewable energy projects progress from concept demonstration to commercial-scale developments, new approaches are needed to capture the relevant physics for small diameter cables on rocky seabeds to reduce the costs and risks of export power transmission and increase operational reliability. These same considerations also apply to the cables and small diameter pipes – such as umbilicals – required by oil and gas projects located on rocky seabeds. Recent experimental testing using the University of Western Australia's unique Large O-tube has enabled the experimental measurement of hydrodynamic forces on small diameter cables and pipes in proximity to smooth and rough beds. The tested conditions extend well beyond the existing published parameter range including much higher KC conditions together with seabed roughness which is comparable in size to the diameter. The results provide design data of great relevance to the ongoing development of marine renewable and conventional oil and gas projects, especially on rocky seabeds. This paper presents a summary of the existing knowledge on the subject as a preface to preliminary test results and gives tentative conclusions on the likely outcomes from this work.",
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Griffiths, T, Teng, Y, Cheng, L, An, H, Draper, S, Mohr, H, Fogliani, A, Mariani, A & White, D 2019, Hydrodynamic forces on near-bed small diameter cables and pipelines in currents, waves and combined flow. in Pipelines, Risers, and Subsea Systems. Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, vol. 5B-2019, The American Society of Mechanical Engineers (ASME), UK, ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2019, Glasgow, United Kingdom, 9/06/19. https://doi.org/10.1115/OMAE2019-95557

Hydrodynamic forces on near-bed small diameter cables and pipelines in currents, waves and combined flow. / Griffiths, Terry; Teng, Yunfei; Cheng, Liang; An, Hongwei; Draper, Scott; Mohr, Henning; Fogliani, Antonino; Mariani, Alessio; White, David.

Pipelines, Risers, and Subsea Systems. UK : The American Society of Mechanical Engineers (ASME), 2019. (Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE; Vol. 5B-2019).

Research output: Chapter in Book/Conference paperConference paper

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AB - The on-bottom stability design of subsea pipelines and cables is important to ensure safety and reliability but can be challenging to achieve, particularly for renewable energy projects which are preferentially located in high energy metocean environments. Often these conditions lead to the seabed being stripped of all loose sediment, leaving the cables to rest on exposed bedrock where roughness features can be similar in size to the cables. As offshore renewable energy projects progress from concept demonstration to commercial-scale developments, new approaches are needed to capture the relevant physics for small diameter cables on rocky seabeds to reduce the costs and risks of export power transmission and increase operational reliability. These same considerations also apply to the cables and small diameter pipes – such as umbilicals – required by oil and gas projects located on rocky seabeds. Recent experimental testing using the University of Western Australia's unique Large O-tube has enabled the experimental measurement of hydrodynamic forces on small diameter cables and pipes in proximity to smooth and rough beds. The tested conditions extend well beyond the existing published parameter range including much higher KC conditions together with seabed roughness which is comparable in size to the diameter. The results provide design data of great relevance to the ongoing development of marine renewable and conventional oil and gas projects, especially on rocky seabeds. This paper presents a summary of the existing knowledge on the subject as a preface to preliminary test results and gives tentative conclusions on the likely outcomes from this work.

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BT - Pipelines, Risers, and Subsea Systems

PB - The American Society of Mechanical Engineers (ASME)

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Griffiths T, Teng Y, Cheng L, An H, Draper S, Mohr H et al. Hydrodynamic forces on near-bed small diameter cables and pipelines in currents, waves and combined flow. In Pipelines, Risers, and Subsea Systems. UK: The American Society of Mechanical Engineers (ASME). 2019. (Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE). https://doi.org/10.1115/OMAE2019-95557