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Damaged Pipeline Section ReplacementFacilitated By Dual Subsea BISEP® Isolation

Managing Pressure, Minimising Risk© STATS GROUP Slide: 2

STATS Group – Subsea Capabilities

Isolation Services

Tecno Plug®

Remote Tecno Plug®

Intervention & Isolation Services

BISEP®

SureTap® Hot Tap Machines

Subsea Modification & Repair

Repair ClampsMechanical Connectors

Abandonment Plugs

Caisson Lifting / Handling Tools


10” Hot Tapping & Plugging, Pipeline Abandonment, Gulf of Mexico

Client: Crimson Gulf

Challenge

• Isolate and abandon a 10” oil pipeline in the Gulf of Mexico, at a water depth of approximately 25 meters.

• Supply personnel and equipment to complete subsea hot tapping and plugging at two locations to facilitate the removal of a short section of pipework as part of a decommissioning project.

Solution

• 10” Subsea hot tap operations, 2x 10” BISEPs, 2x Hot Tap Fittings, 2x Slab Valves, Mechanical Connector.

Benefits

• BISEPs allowed flushing and purging capabilities, removing oil prior to breaking containment.

• The BISEP prevented additional hot tapping and reduced the number of fittings installed on the pipeline, saving time, reducing risk and expenditure.

• Pipeline safely abandoned according to plan and without incident.


Work Scope Overview• Vent the isolated section to subsea ambient • Disconnect umbilical from upstream BISEP – seal verification tests to be performed using BISEP diver control panel.

(Note: if poor visibility prevents gauge reading umbilical can be used as contingency)

Venting of Isolated Section of Pipeline


28” Subsea Pipeline Isolation & Repair, Yacheng Pipeline, China

Client: COOEC Subsea Technology Co. Ltd

Challenge

• 780km 28” subsea gas export pipeline suppling gas to Hong Kong had become damaged by an anchor at a water depth of 90m

• Provide temporary double block and bleed isolation to allow a quick and safe repair without depressurising or flooding the entire pipeline

• Ensure any seawater that enters the system is removed before the pipeline resumes operation

Solution

• 28” Subsea hot tap operations, 28” BISEP, 4x 28” Remote Tecno Plugs and a 28” Flangeless Subsea Launcher

• Two PLEMs and damaged section of pipeline removed and replaced while pipeline remained at 50 bar

Benefits

• No requirement to depressurise entire pipeline

• Subsea repair completed safely and on schedule – 8 weeks

• No seawater entered the pipeline system


8” Subsea Pipeline Isolation & Repair, North Pailin Field, Gulf of Thailand

Client: Chevron Thailand

Challenge

• 8” Gas condensate export pipeline has suffered anchor strike damage to a wye section of pipeline at 90m

• Install a permanent bypass and temporary double block and bleed isolation to allow damaged wye section to be removed and capped

• Maintain production during repair and remediation activities

Solution

• Numerous subsea hot taps, 3x BISEPs, 6x Subsea Mechanical Fittings, 3x Subsea Mechanical Connectors and 3x Subsea Abandonment Plugs

Benefits

• Production maintained during repair and remediation activities

• No seawater entered the pipeline system


for more information visit

www.statsgroup.com

Thank You For Your AttentionQuestions?


Copyright & Disclaimer

Copyright

Copyright of all published material including photographs, drawings and images in this document remains vested in STATS (UK) Ltdand third party contributors as appropriate. Accordingly, neither the whole nor any part of this document shall be reproduced in anyform nor used in any manner without express prior permission and applicable acknowledgements. No trademark, copyright or othernotice shall be altered or removed from any reproduction.

Disclaimer

Although STATS Group believes that the Presentation and the references therein are based upon reasonable assumptions, it can giveno assurance that the actual results will be as set out in the Presentation. STATS Group is making no representation or warranty,expressed or implied, as to the accuracy, reliability or completeness of the Presentation or the data referenced therein, and neitherSTATS (UK) Ltd nor any of its directors, officers or employees will have any liability to you or any other persons resulting from youruse.

STATS Group consists of many legally independent entities, constituting their own separate identities. STATS Group is used as thecommon brand or trade mark for most of these entities. In this presentation we may sometimes use “STATS”, “we” or “us” when werefer to STATS Group companies in general or where no useful purpose is served by identifying any particular STATS Groupcompany.

Damaged Pipeline Section ReplacementFacilitated By Dual Subsea BISEP® Isolation


Work Scope Overview• Seabed to be dredged, and prepared to allow landing of handling frame (if required) and

installation of hot tap fittings.• Concrete coating removed at fitting installation locations• Overboard hot tap assembly and position onto downstream section of pipeline.

Downstream Location Upstream Location

Topside / Deployment of Stack Up


Work Scope Overview• Install mechanical hot tap fitting onto pipeline• Perform downstream hot tap fitting annulus test – (test

pressure/duration TBC)• Perform stack up joint integrity test – 15 minutes @ 1.1 x

pipeline operating pressure

Hot Tap Fitting Tests


Work Scope Overview• Perform Hot tap Operations , Retrieve Cutter c/w coupon• CLOSE slab valve• Perform double block seal integrity tests of slab valve – duration = 15 minutes per seal test• Unbolt hot tap machine from slab valve and recover to surface• Deploy and install BISEP onto slab valve

Hot Tap Operations & BISEP Installation


Note: Downstream BISEP not deployed yet

• Disconnect umbilical's and retrieve to surface and relocate to upstream location.• Repeat installation of stack up/ hot tapping / BISEP installation at upstream location.

Upstream Stack Up Operations


Work Scope Overview• Perform flange integrity test between BISEP and slab valve (downstream) – 15 minutes @ 1.1 x pipeline operating

pressure• Initiate pipeline shut in (production to cease / pipeline to remain pressurised).• Equalise BISEP launcher pressure with pipeline operating pressure • OPEN Slab valve and Deploy upstream BISEP into pipeline –note BISEP orientates toward upstream direction • Activate BISEP• Ensure positive annulus pressure achieved – indicating sealing integrity of both seals• Activate hydraulic accumulator system• Disconnect hydraulic umbilical

Upstream BISEP Deployment Operations


Work Scope Overview• Relocate vessel to downstream BISEP• BISEP Perform flange integrity test between BISEP and slab valve – 15 minutes @ 1.1 x pipeline pressure• Equalise BISEP launcher pressure with pipeline pressure• Open Slab valve, Deploy downstream BISEP into pipeline – note BISEP orientates toward downstream direction• Activate BISEP• Ensure positive annulus pressure achieved – indicating sealing integrity of both seals

Downstream BISEP Deployment Operations


Work Scope Overview• Vent the isolated section to subsea ambient • Disconnect umbilical from upstream BISEP – seal verification tests to be performed using BISEP diver control panel.

(Note: if poor visibility prevents gauge reading umbilical can be used as contingency)

Venting of Isolated Section of Pipeline


Downstream BISEP

• Perform Secondary seal leak off test – 1 hour• Vent annulus to ambient• Perform primary seal pressure build up test – 1 hour*• Perform 4 hr integrity seal

During 4 hr hold, vessel to relocate to Upstream BISEP

Upstream BISEP• Perform Secondary seal leak off test – 1 hour• Vent Annulus to ambient• Perform primary seal pressure build up test - 1hour• Commence 4 hr integrity hold

NOTE: During 4 hr hold period vessel to locate to each BISEP and perform status checks when possible to ensure test stable.

*Option to relocate to DS location and perform secondary seal test then vent annulus to have combined 4hr test of primary seals

BISEP’s Double Block and Seal Verification


• Issue isolation certificate for both upstream and downstream BISEP’s after 4 hr hold• Flush isolated section of pipeline to ensure free of hydrocarbons – utilise 2” ports on the BISEP launchers

NOTE: If damaged section is leaking then fit temporary low pressure banded clamp to prevent product leakage during flushing

• Deploy pipe cutter at dedicated locations and perform pipe cut(s)• Retrieve pipe cutting machine(s) and retrieve pipe cut sections or cap off damaged section with

pipe end abandonment plugs

Pipeline Destruction Works


Overview of Work Scope• Deploy subsea mechanical connectors and install onto each open end of pipe • Perform annulus test for 1 hour - TBC• Connect replacement pipeline section to each connector

Installation of Mechanical Connectors and Flexible Pipe


• Flush out entrained seawater from pipe section – if required• Perform 1.1 x MAOP joint reinstatement leak test using the BISEPs at the test boundary*• Hold leak test for 1 hour (TBC)

*Note: Reverse pressure capability of BISEP is 50% of the isolation pressure ratingE.g. Isolation pressure rating of 600# BISEP is 102bar (1500psi)

Reverse pressure capability is 51bar (750psi) differential pressuretherefore, to perform a 100bar leak test, the outboard, isolated pipeline pressure need to be 49bar or greater.

Flexible Pipe Flange Joint Leak Test


• Vent test pressure to equalise with pipeline pressure

BISEP Unset Operations


Overview of Work Scope• Deploy hydraulic umbilical to BISEP to unset and retract BISEPS into their launchers • CLOSE slab valves and perform dual seal integrity tests – duration 15 minutes per test• Depressurise BISEP launcher, ensure vent valves are open then unbolt from slab valve• Retrieve to surface

BISEP Retrieval Operations


Overview of Work Scope• To enable future pigging operations, deploy Hot Tap Machine (HTM) c/w scarfed (or pigging barred)

completion plug and install onto slab valve• Perform flange integrity test – 15 mins• Equalise HTM with pipeline pressure• OPEN slab valve and deploy completion plug into hot tap branch flange• Lock completion plug into position

Completion Plug Installation


Overview of Work Scope• Disengage HTM from completion plug• Vent hot tap assembly to subsea ambient and perform PBU test of completion plug seal• Disconnect slab valve and HTM from hot tap fitting and retrieve to surface

Retrieval of STATS Equipment


Overview of Work Scope• Deploy RTJ blind flange c/w gasket and install.• Work Scope complete

Work Scope Completion


for more information visit

www.statsgroup.com

Thank You For Your AttentionQuestions?


Copyright & Disclaimer

Copyright

Copyright of all published material including photographs, drawings and images in this document remains vested in STATS (UK) Ltdand third party contributors as appropriate. Accordingly, neither the whole nor any part of this document shall be reproduced in anyform nor used in any manner without express prior permission and applicable acknowledgements. No trademark, copyright or othernotice shall be altered or removed from any reproduction.

Disclaimer

Although STATS Group believes that the Presentation and the references therein are based upon reasonable assumptions, it can giveno assurance that the actual results will be as set out in the Presentation. STATS Group is making no representation or warranty,expressed or implied, as to the accuracy, reliability or completeness of the Presentation or the data referenced therein, and neitherSTATS (UK) Ltd nor any of its directors, officers or employees will have any liability to you or any other persons resulting from youruse.

STATS Group consists of many legally independent entities, constituting their own separate identities. STATS Group is used as thecommon brand or trade mark for most of these entities. In this presentation we may sometimes use “STATS”, “we” or “us” when werefer to STATS Group companies in general or where no useful purpose is served by identifying any particular STATS Groupcompany.

damaged pipeline section replacement facilitated by dual ... group.pdfform nor used in any manner...

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