The project included modification of the PLEM to allow disconnection of submarine hoses and installation of the launching spool without impacting the subsea environment.
The pipe spool was installed with drains and vents between the PLEM valve and the submarine hoses for product recuperation before hose removal.
The bypass approach involved creating an alternative export pipeline network that began at a platform bypassing the gas PLEM, which enabled gas to flow to a subsea isolation valve (SSIV) before connecting with the 32-inch export sealine to an onshore gas plant.
After shutting down the platform, TDW used its STOPPEE plug technology to isolate several lines, thereby sidestepping the need to flood the entire network with salt water during the PLEM replacement.
As a result of the work on the Temsah Concession pipeline network, Petrobel was able to resume production, and gas flowed once again through the new central PLEM.
Stolt installed the PLEM handling frame on the Seaway Falcon's port side to facilitate manual welding the PLEMS to each end of the flowline, which Stolt lifted from the seabed floor to secure the pipe in the frame.
Stolt completed the welds on the deck of the Seaway Falcon and then lowered the flowline and each PLEM to the target locations at each well site for final lay down.
Fabrication of the subsea PLEM
and gravity structure was completed at a Gulf Coast fabrication facility and shipped to the job site.
Communication to the surface is by a link from an underwater acoustic modem mounted on the PLEM
and powered by two lithium battery packs wired in parallel.
They have prepared this book for aspiring subsea engineers, a discipline described in the preface as involving the "design, analysis, construction, installation and integrity management of subsea wellheads, trees, manifolds, jumpers PLETS and PLEMs
The project scope consists of the installation and replacement of subsea equipment comprised of manifolds, PLEMs
(Pipeline End Manifolds), jumpers and associated hardware in 6,800 feet of water, as well as assisting BP with complete commissioning and start-up activities.
Comprised of a jacket, float-over topsides, pipelines, umbilicals, PLEMS and living quarters for 66 people, the Su Tu Vang Central Processing Platform (CPP) is a fully integrated EPCI project.