TDW Offshore completes pipeline isolation projectProjects and Operations // September 24, 2012
TDW Offshore Services (TDW) has successfully completed a subsea pipeline pressure isolation operation in the Gulf of Mexico.
Carried out at a depth of 113m against 870 psig, the isolation enabled the safe and effective tie-in of a piggable wye to the Mississippi Canyon Gas Pipeline, a 30in natural gas line running between the West Delta 143 platform – a hub facility for deepwater oil and gas production – and the Venice Gas Plant in Louisiana.
The isolation project utilized two remote-controlled 30in SmartPlug dual module pressure isolation tools to isolate 45 miles of pipeline.
“The SmartPlug isolation tool is certified to ‘Safety Class High’ in accordance with OS-F101 for Submarine Pipeline Systems and is uniquely suited for use in connection with diving operations,” said Bjørn-Olav Gilje, project manager for TDW.
Each tool included two plug modules and two pigging modules. One of the tools provided double block isolation on the high pressure side of the tie-in location. The first module on the second tool provided a hydraulic locked barrier of the high pressure side for the divers installing the wye.
The second module on the second tool was used to perform a leak test to verify integrity of the new wye after installation.
Following launch, TDW technicians aboard dive support vessel Norman Commander used the remotely-operated SmartTrack tracking and pressure monitoring system to continuously monitor the locations of the SmartPlug tools as they traveled to their subsea set destinations.
The SmartTrack system uses two-way, through-wall, electromagnetic communication between a transponder and a receiver to track tool progress. Once the tools were set, the isolation period was approximately two and a half weeks.