abstract of papers:- - malaysian gas...

Abstract of Papers:-

The Malampaya Deep Water Gas to Power Project is a development in the Malampaya and

Camago reservoirs that uses deep water subsea wells connected by wet-gas flow lines to a

platform in shallow water, where gas and condensate are processed. Dry gas then travels via

a 504 km subsea Gas Export Pipeline (GEP) to the Malampaya Onshore Gas Plant (MOGP) at

Batangas for final processing and fiscal metering before the gas is dispatched to customers

downstream.

The primary emergency shutdown valve (ESDV) on the GEP riser, having been discovered to

be defective, was unable to provide an acceptable isolation for the platform from the GEP

inventory in the event of an emergency shutdown. This mandated that the ESDV be

removed and replaced, along with its neighbouring manual block valve. This work

necessitated a plant shutdown since gas export is not possible while repairs proceed. A

major shutdown, planned for over a year, was due to take place in February/March 2010. A

range of rejuvenation work was scheduled, including replacement of the aforementioned

valves.

Abstract of Papers (cont’d) :-

Two options presented themselves: i) to bleed down the entire GEP—a protracted and very

costly alternative—and ii) to deploy pressure isolation of the line downstream of the valves.

The latter method was preferred, with isolation using remote-controlled plugging

technology known as the SmartPlug® was provided by TDW. SmartPlug® is a remote-

controlled (umbilical-less) pipeline isolation system effective in isolating oil and gas

pipelines. Designed, manufactured, and tested to withstand MAOP (Maximum Allowable

Operating Pressure), SmartPlug® allows repairs and maintenance to be carried out while

maintaining pipeline pressure.

Several challenges were apparent. As this was the first ever pressure isolation of its kind

undertaken at the Malampaya platform by SPEX, there were understandable concerns

about viability. This paper describes the steps from the site visit and engineering feasibility

study of applying pipeline plugging technology, to offshore mobilization and then to

execution. Fortunately, the operation proceeded according to plan, and was judged a

success by the operator.

www.tdwilliamson.com

By Rolf Gunnar Lie, T.D. Williamson Asia Pacific Pte Ltd, Singapore

7th Asian Pipeline Conference and Exhibition

“Overcoming Challenges in Pipelines”

Malampaya Gas Export Line

Valve Replacement

using

Remote-controlled Plugging Technology

http://www.tdwilliamson.com/en/Pages/Home.aspx

57th Asian Pipeline Conference & Exhibition 2011 5

Agenda

Malampaya pipeline system.

Why valve change out

Gas Export Line – Shut Down activities & Isolation scope

Pipeline Isolation by use of SmartPlug®

Pigging of the SmartPlug®

Actuation System and Communication System

Benefits in using pipeline pressure isolation

Launching, setting, monitoring and retrieval

Results

Safety




Malampaya Pipeline System




Malampaya gas Export Line – Isolation scope

Gas Export Line to onshore

processing facility (isolation

location) Defect ESDV and Manual Valve



87th Asian Pipeline Conference & Exhibition 2011

Why Valve Change Outs!

8

A. If the primary emergency shutdown valve (ESDV) or Launcher Valves (MOV) fail to provide an acceptable isolation for the platform from the Gas Export Pipeline inventory in the event of an emergency shutdown it represents a safety risk and the valve therefore has to be removed and replaced.

B. Why? Because even a pin hole leak above the leaking valve can cause a CatastropicEvent at the platform or has too large impact for the operator to accept the risk!

C. The leakage of valves are generally determined by acoustic leak detection.

D. Leakage rate criteria are:

i. MOV’s in H2S lines: >=0,01kg/s

ii. SDV Gas Lines: >=0,1kg/s

iii. SDV Oil lines: >=6kg/min

E. Shell does this globally but have different leakage acceptance criteria.

F. Valve replacement work is generally done during planned shutdowns as gas export will not be possible for the duration of the work.

G. Thinking is preventive planned maintenance rather then emergency response.




Possible solutions to the problem

Live with a defective ESDV at the platform – NO, because of

safety

Replace the ESDV relying solely on a single SSIV flapper

type valve for isolation from the Gas Export Line (single

isolation) – NO, because of safety

Depressurise and purge the entire GEP, then replace ESDV

– NO, because of Cost

Using of high pressure Isolation Plugs - YES




Benefits in using SmartPlug®

FEATURE BENEFIT

Eliminates

displacement of

product

• No bleed-down

• Reduced chemicals to

treat water

• Reduced nitrogen to

purge

Eliminates re-

commissioning of

pipelines

• No disposal of hydrates

• No disposal of chemicals

or contaminated water

• No full line drying

Eliminate

shutdown

completely

• Production can continue

during maintenance

Allows phased de-

commissioning, or

start-up of new

facilities

Production continues, or

starts while construction

work is on going

THE REAL BENEFIT

• Reduces pipeline

down time

• Saves money

• Increases

production & profits




Isolation by use of SmartPlug®

The TDW SmartPlug® is a remotely controlled and

operated (umbilical-less) pipeline isolation system used

for isolation of oil and gas pipelines.




Pigging of the SmartPlug®

SmartPlug is a bi –directional piggable tool.

Travels with the flow in the pipeline.

Negotiate 3D bend , sometimes as small as 1.5D bends.

Negotiate valves, T’s.

Pre –engineering always include piggability study.

Onboard tracking and positioningsystem.




SmartPlug® Actuation System




SmartPlug® Communication System




Project Execution

Steps to be achieved:

1. Engineering

2. Equipment and personnel mobilization

3. Launching of the SmartPlug® & pigging

4. Setting of the SmartPlug®

5. Monitoring while ESDV replacement is ongoing.

6. Un-setting and retrieval




Setting and Monitoring

Manual valve

ESDV

SmartPlug® Set location




Results

The defective ESDV and manual block valve were

successfully removed and replaced and the integrity safety

barrier in the GAS Export Line re-established.

The SmartPlug® offered a quick and effective solution to an

otherwise costly and complicated problem.




Safety




Acknowledgements

Co-Author: Gerald Mr. Gerald Misajon, Maintenance Engineer, Shell Philippines Exploration and Production, Manila

Nathan Roberts, Discipline Lead - Mechanical Engineering, Shell Philippines Exploration, Manila

Nathan Stephenson, Project Manager, Sarawak Shell Sdn Berhad /Sabah Shell Petroleum Co Ltd, Kuala Lumpur

Bård Kloster, Offshore Supervisor SmartPlug® operation, TDW Offshore Services AS, Stavanger, Norway




Contact details:

Rolf Gunnar Lie

T.D. Williamson Asia Pacific Pte Ltd

4 Tech Park Crescent

SINGAPORE 638128

Phone: +65 96651 3837

E-mail: [email protected]

® Registered trademarks of T.D. Williamson, Inc. in the United States and in foreign countries. ™ Trademarks of T.D. Williamson, Inc. in

the United States and in foreign countries.

Thank you for your

attention!



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