In order to develop the rich natural gas fields beneath the South China Sea, offshore Malaysia, Petronas proposed the Sabah Sarawak Gas Pipeline.
However, construction of the project has by no means been a small feat, with construction contractor Punj Lloyd overcoming undulating mountains, dense rainforests, and unrelenting wet weather.
Petronas’ plans to develop the gas fields offshore Sabah involves construction of the proposed Sabah Oil and Gas Terminal (SOGT) at Kimanis, which is scheduled for completion in 2013.
Once operational, the terminal will be able to receive, store, and export up to 300,000 bbl/d of crude oil, as well as receive, process, compress, and transport up to 1.25 Bcf/d of gas produced from the Gumusut/Kakap, Kinabalu Deep and East, Kebabangan, and Malikai fields.
The 512 km, 36 inch diameter Sabah Sarawak Gas Pipeline (SSGP) will transport 750 MMcf/d of gas from the SOGT to the Petronas LNG Complex at Bintulu, Sarawak.
It is being constructed using API 5L X70 steel grade pipe, with a thickness range of 14, 17, and 20 mm, and will have a design pressure of 96 bar.
In 2008, Petronas awarded Punj Lloyd an engineering, procurement, construction, and commissioning contract for the SSGP, which includes:
– Cathodic protection
– A launcher station at Kimanis
– A compressor station at Bintulu
– Metering stations at both Kimanis and Bintulu
– Intermediate pigging stations at Lawas, Long Lama, and Bintulu
– 22 block valve stations
– Six future tap-off points along the pipeline.
Also included in the scope of the contract are SCADA, telecommunication, a ﬁre and gas system, leak detection, and a gas management system.
In 2009, Punj Lloyd compiled a project team consisting of 3,000 workers from India, Malaysia and Indonesia.
Punj Lloyd Executive Vice President P.K. Chand says that the SSGP project is one of the most challenging pipeline projects the company has ever undertaken.
Some of the exceptional challenges Punj Lloyd faced included rough mountain terrain with rocks and swampy stretches, thick vegetation consisting of dense rainforests and oil palms, constant wet weather, and stringent regulatory approvals.
Mr Chand says “The terrain is extremely harsh, and is made up of rocky, mountainous slopes with an altitude of up to 3,300 feet, dense forests, swamps and palm oil plantations. Steep, 76° slopes have been encountered, and the undulating terrain has resulted in 39 per cent of the pipeline consisting of field cold bends – a total of 16,380 bends.
“Thinking out of the box to find a solution to the inhospitable terrain, our project team modified trailers and sledges to suit the mountainous terrain. All the vehicles were provided with full-width off-road tyres and excavators with special track grip for steep slope locations. Our project team has also used specially designed internal crawlers for non-destructive testing of the pipeline.”
In addition to the specialised equipment Punj Lloyd is using for pipe transportation, stringing, and welding, the company has also mobilised heavy-duty winches and walking spider excavators for the installation of the pipeline on steep slopes.
As most of the pipeline route crosses challenging terrain, including hillsides, rocks, swamp, and dense forest areas, approach roads were non-existent. Punj Lloyd had to construct and maintain more than 200 km of inaccessible right-of-way (RoW), build approach roads and bridges, and develop and maintain the logging roads.
The company used air crane helicopters for the transportation of the pipes and bends, and for hauling and stringing in the 35 km stretch in Limbang, where land transportation was a high-risk activity.
Pipeline construction involved as many as 3,000 crossings, including eight major and 305 smaller perennial rivers, 27 major road crossings, 88 minor road crossings, and 20 horizontal directionally drilled (HDD) crossings.
In addition to HDD, Punj Lloyd used the conventional crossing, open-cut crossing, and thrust-boring methods to install the pipeline through these areas.
Mr Chand says that under Malaysian law, the project required implementation of stringent regulations by the Department of Safety and Health, Department of Environment, and Department of Irrigation and Drainage
“Punj Lloyd followed all regulations imposed by these departments, maintaining the highest standards of health, safety and environment,” says Mr Chand.
Abridged version of Pipelines International 2012 (pdf)