Cable Burial in Subsea Cables davies... · 1 Changing the way you succeed. 1 Cable Burial in Subsea Cables Who is Canyon Offshore What have we done in cables outside O&G What are

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Changing the way you succeed. 1

Cable Burial in Subsea Cables

Who is Canyon Offshore

What have we done in cables outside O&G

What are the seabed conditions that are encountered

What equipment is there to burial cables

Who sets and how do you achieve the DOB required

What happens if you don’t

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Canyon’s Current Trenching Equipment

Our fleet of purpose built trenchers are

available to trench and backfill in water

depths up to 2500m.

Operating in tracked, free fly or pipe follow

mode, along with unique jetting and backfill

tooling, each system can be customised

based on project soil conditions and desired

trench results.

Current fleet consists of 5

Trenchers

i-Trencher – 1725 HP

T1200 – 1200HP

T750 - 750 HP

T600 - 600 HP

T1500 – 1500HP

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Grand Canyon 1, 2 & 3 Trenching Support Vessel

Vessel Overview

DP 3 , Ice Class

Long term charter from Volstad

Purpose built trenching vessel

Clean & Comfort Class

Accommodation for 108 POB

250 MT crane

125m LOA ,beam 26m, deck space 1600 m2

Vessel Spread

Reeled or Carousel lay spread

Jet Trencher (T1200, T1500 or T750)

Heavy Soils Trencher (itrencher)

2 x WROVs

The Grand Canyon is the host vessel to the equipment that form

the Primary Trenching Solution. Since entering service in 2012, it

has acted host vessel on a number of projects on a global

footprint

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Interconnector , Export Cable & Offshore Wind Farm Experience

BritNed - IC

EWIP – IC

NorBolt - IC

Greater Gabbard

Thornton Bank

Sherringham Shoal

London Array

Meerwind

Northwind

Nord See Ost

Borkum West 2

Dan Tysk

Baltic 1 - E

Baltic 2 - E

Borkum Riffgund - E

Dolwin 2 - E

Butendiek – E

Sandbanks - E

WMF Export Ends

Nord See 1 - E

Norrthwind, Belwind, Alstom

Remedial – IA & E

Dudgeon – IA

Galloper – IA

Blyth Demonstrator - IA

CMS – IC 2017

Racebank – E remedial

NSL – IC 2018-2021

Nordlink – IC 2018

Hornsea – IA 2018

Beatrice – IA 2018

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Seabed Conditions

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Tools in the box

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Tool Selection Process – Burial Protection Index

Very Soft

Clay 10 kpa

Firm

Clay 40kpa

Coarse sand

Very Stiff

Clay Fine

sand

Burial P

rote

ctio

n In

de

x

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Mole, P., Featherstone, J. and Winter, S. (1997) Cable

Protection –

Solutions Through New Installation and Burial Approaches.

SubOptic ’97.

Burial Depth (m) 1 2 3

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Soils Overview-Tool Selection and Risk Matrix

During the bids / tender phase complete

full Geotechnical Analysis on data

provided

Work with client to define any areas of

risk and then select tool to achieve

contracted burial depth

Complete Programme of Work in

conjunction with client construction

programme and amended as client more

fully understands his customers

expectations

Submit contractual and Reasonable

Endeavours clauses to meet requirements

of the contract

Complete all engineering, procedures and

survey reporting as required by the client

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Reasonable Endeavours

Why Reasonable? Why Not Best?

used to qualify a schedule and therefore price

to complete a burial operation

Used to mitigate that the survey may not be

representative of the actual conditions found

and therefore it used where Adverse Soil

Conditions are encountered

Limits the use of one tool in favour of another

Limitation of obligation (liability) on the

contractor to perform the works

Excludes certain other remedial protection.

Its NOT a place to hide – old style

protectionism

It is about Risk share and balance

Used extensively in renewables projects

Though some Clients would rather you went

to FIDIC – Silver book

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Thank You

Bringing Past Experience to a Safer Future John Davies

Director Seabed Intervention

Canyon Offshore Ltd

http://www.helixesg.com/canyon/

Helix House, Kirkton Drive, Pitmedden Industrial

Estate, Dyce, Aberdeen, AB21 0BG

Tel: +44 (0)1224 351800

DDI: +44 (0) 1224 755015

Mob: +44 (0) 7971 223383

Fax: +44 (0)1224 351801

Email: [email protected]