The University of Southampton
University of Southampton Institutional Repository

The impact of submarine slides on pipelines: outcomes from the COFS-MERIWA JIP

The impact of submarine slides on pipelines: outcomes from the COFS-MERIWA JIP
The impact of submarine slides on pipelines: outcomes from the COFS-MERIWA JIP

This paper presents key outcomes of a 3-year Joint Industry Project funded by 6 Operators on the impact of submarine slides on pipelines. This JIP developed new techniques to simulate slide runout, and assess the resulting loading and deformation of seabed pipelines. The work was distilled into guidance for practical application, which has found adoption on projects. The JIP spanned (i) characterization of soils at the solid-fluid transition, (ii) computational modelling of slide runout - via depth-averaged and continuum finite element methods, (iii) physical and numerical modelling of slide runout and pipeline impact, and (iv) analytical studies of pipeline response during slide loading. These elements combine to provide an improved practical basis for quantifying the risk associated with slide-pipeline interaction. To characterize very soft seabed soils, a new geotechnically-based framework was devised based on extensive measurements of different soils. This framework spans the solid-fluid boundary that is crossed as slides evolve into a debris flow and turbidity current. It is shown that the geotechnical link between water content and shear strength extends continuously - with no phase transformation - far into the fluid domain, allowing a single rheology to be applied throughout. Computational modelling of slide runout used a hierarchy of methods, from large deformation finite element analysis (LDFE) (with rate effects and softening at soil element level), through depth-averaged runout, to energy-based analytical solutions. In some regimes of behavior the simpler methods suffice, allowing efficient use of Monte Carlo methods to tackle uncertainty. More complex runout modes can be replicated by newly-developed LDFE techniques. From a runout analysis results, pipeline impact loads can be assessed using new solutions for the bearing capacity and drag forces on pipelines developed from numerical and physical modelling, which again unify concepts from fluid dynamics and geotechnics. Finally, simple analytical methods for assessing the structural response of a pipeline to a known slide loading are provided. These solutions allow rapid assessment of the response of a pipeline to a specified slide loading. These advances improve the methods available for quantitative assessment of slide runout and slide-pipeline interaction, allowing better determination of the resulting geohazard risk.

1820-1850
Curran Associates
White, D.J.
a986033d-d26d-4419-a3f3-20dc54efce93
Randolph, M.F.
75caa33a-e630-4ae8-84cd-758797bf9633
Gaudin, C.
4d1197f0-7c69-4301-8877-33f840784685
Boylan, N.P.
a74ded07-8f6f-4198-bdc9-76e9693091b1
Wang, D.
8252495a-d031-44fa-9f21-6e8c76164aaa
Boukpeti, N.
3a09b546-4d1a-498d-986a-02165e5ab4fc
Zhu, H.
827887ad-e19b-4ba2-b53c-1263023adfe8
Sahdi, F.
4440c2e1-cec9-4cbf-b101-7722b9535ea5
White, D.J.
a986033d-d26d-4419-a3f3-20dc54efce93
Randolph, M.F.
75caa33a-e630-4ae8-84cd-758797bf9633
Gaudin, C.
4d1197f0-7c69-4301-8877-33f840784685
Boylan, N.P.
a74ded07-8f6f-4198-bdc9-76e9693091b1
Wang, D.
8252495a-d031-44fa-9f21-6e8c76164aaa
Boukpeti, N.
3a09b546-4d1a-498d-986a-02165e5ab4fc
Zhu, H.
827887ad-e19b-4ba2-b53c-1263023adfe8
Sahdi, F.
4440c2e1-cec9-4cbf-b101-7722b9535ea5

White, D.J., Randolph, M.F., Gaudin, C., Boylan, N.P., Wang, D., Boukpeti, N., Zhu, H. and Sahdi, F. (2016) The impact of submarine slides on pipelines: outcomes from the COFS-MERIWA JIP. In Offshore Technology Conference 2016 (OTC 2016). vol. 2, Curran Associates. pp. 1820-1850 .

Record type: Conference or Workshop Item (Paper)

Abstract

This paper presents key outcomes of a 3-year Joint Industry Project funded by 6 Operators on the impact of submarine slides on pipelines. This JIP developed new techniques to simulate slide runout, and assess the resulting loading and deformation of seabed pipelines. The work was distilled into guidance for practical application, which has found adoption on projects. The JIP spanned (i) characterization of soils at the solid-fluid transition, (ii) computational modelling of slide runout - via depth-averaged and continuum finite element methods, (iii) physical and numerical modelling of slide runout and pipeline impact, and (iv) analytical studies of pipeline response during slide loading. These elements combine to provide an improved practical basis for quantifying the risk associated with slide-pipeline interaction. To characterize very soft seabed soils, a new geotechnically-based framework was devised based on extensive measurements of different soils. This framework spans the solid-fluid boundary that is crossed as slides evolve into a debris flow and turbidity current. It is shown that the geotechnical link between water content and shear strength extends continuously - with no phase transformation - far into the fluid domain, allowing a single rheology to be applied throughout. Computational modelling of slide runout used a hierarchy of methods, from large deformation finite element analysis (LDFE) (with rate effects and softening at soil element level), through depth-averaged runout, to energy-based analytical solutions. In some regimes of behavior the simpler methods suffice, allowing efficient use of Monte Carlo methods to tackle uncertainty. More complex runout modes can be replicated by newly-developed LDFE techniques. From a runout analysis results, pipeline impact loads can be assessed using new solutions for the bearing capacity and drag forces on pipelines developed from numerical and physical modelling, which again unify concepts from fluid dynamics and geotechnics. Finally, simple analytical methods for assessing the structural response of a pipeline to a known slide loading are provided. These solutions allow rapid assessment of the response of a pipeline to a specified slide loading. These advances improve the methods available for quantitative assessment of slide runout and slide-pipeline interaction, allowing better determination of the resulting geohazard risk.

Full text not available from this repository.

More information

Published date: August 2016
Venue - Dates: Offshore Technology Conference 2016 (OTC 2016), , Houston, United States, 2016-05-01 - 2016-05-04

Identifiers

Local EPrints ID: 420513
URI: http://eprints.soton.ac.uk/id/eprint/420513
PURE UUID: 94938091-8ba2-41eb-b6db-8bbb5b8ecf70
ORCID for D.J. White: ORCID iD orcid.org/0000-0002-2968-582X

Catalogue record

Date deposited: 09 May 2018 16:30
Last modified: 15 Apr 2021 01:55

Export record

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×