TDW Completes Subsea Pipeline Isolation in Gulf Of Mexico

TDW Offshore Services (TDW), a leading supplier of pipeline services and equipment has successfully completed a subsea pipeline pressure isolation operation in the Gulf of Mexico. Carried out at a depth of 370 ft (113 m) against 870 psig, this isolation enabled the safe and effective tie-in of a piggable wye to the Mississippi Canyon Gas Pipeline, a 30-inch 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 30-inch 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,” says Bj?rn-Olav Gilje, project manager for TDW.

Each tool was composed of 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.

“TDW worked with the client and their contractors over several months to ensure that associated risks were evaluated and mitigated,” Gilje adds. “This thorough up-front planning resulted in a successful tie-in operation for our client. Working together achieved a result that we are proud to have been part of.”