TDW Offshore Services AS in May successfully completed a key pipeline pressure isolation and joint testing operation offshore western Borneo in Malaysia for Sarawak Shell Berhad. TDW worked on platform F23P-A (Fig. 1), part of operations run by Sarawak Shell Berhad 80-200 km from Miri and Bintulu.
The operation took place on a gas export line forming a portion of the line running from F23P-A to the E11R-A platform. The network then extends to one of four major trunklines connected to an LNG plant onshore in Bintulu. Sarawak Shell Berhad's operations also include the M3, B11, E11 R-B, and F6 platforms. Shell operates the development for a joint venture between it and Petronas Carigali Sdn. Bhd.
The pressure isolation allowed Shell to install a motor-operated valve (MOV) in preparation for installation of a new compressor module. TDW used a 30-in. version of its SmartPlug isolation tool (Fig. 2) to isolate the section of the line requiring a new valve, pigging it in from the launcher past the site designated for valve installation, and safely isolating the line in preparation for cutting, welding a new flange to it, and valve installation.
To ensure the flange was properly installed without pressurizing the entire line, TDW tested the weld with a joint tester, with valve installation following testing. This process required the affected portion of the gas export line to be isolated for 1 month.
TDW says the operation allowed Shell to avoid the costs incurred by bleeding down the line to undertake repairs.
TDW built the SmartPlug tool and joint tester used by the company at its headquarters in Stavanger, and used local support from personnel based in Singapore and its agent in Malaysia, Amserve Engineering, during the operation.
The isolation operation on the F23P-A took place as part of a 3-year framework agreement reached in 2009 between TDW and Sarawak Shell Berhad to provide pipeline pressure isolation services and hot tapping services, as well as a subsea repair clamp.