Shell's tie-in of the Perdido oil pipeline in the US Gulf of Mexico is the deepest tie-in ever preformed to an already operating system (5,000 ft) . It is also the first to use a prefabricated foundation and jumper. Shell projects Perdido production of 130,000 b/d, with first oil slated for early 20 10. This article examines preparation for the foundation and jumper installation. Pipelines

HOOPS connection

The only path out from Shell's Perdido development is south through harsh terrain and into a canyon running north. Tie-in lies 200 miles south of Houston. The closest platform is Hoover, 7 5 miles to the north but lacking large-diameter connections or expansion capacity (Fig. 1).

Tie-in of Perdido is the first deepwater postinstalled subsea connection. It was designed to reduce mainline downtime, allow for future reconfiguration (or disconnection) , and use proved components.

PERDID0-To-SH0RE INFRASTRUCTURE

Design and installation incorporated lessons Shell learned repairing the Mars pipeline, damaged by an anchor drag during Hurricane Ivan in 2005. Mars repair used dual sleds with a jumper connection. Alignment of the various components, including the large jumper, proved difficult and the project's gantry system had to be redesigned. Repairs included reinstalling a 3,500-ft section of the Delta 20-in. pipeline system upstream of the MP69 P pump station and reconnecting it to the Odyssey 20-in. line (OGJ, Aug. 22, 2005, p. 75).

The Perdido connection to the Hoover Offshore Oil Pipeline System (HOOPS) attaches the Hoover pipeline to a smaller jumper which in turn is attached to a piggableY before reconnecting to the main line (Fig. 2). The other branch of the Y will be used to connect the Perdido line. The frame used (Fig. 3) fixes the alignment of the entire system, allowing the jumper to travel out on the initial mobilization.

Vessel, modeling

Oceaneering's Olympic Intervention IV will transport the hardware and tools required for the installation and perform surface duties during the installation. The vessel features a satellite commu- nications system capable of trans- mitting streaming video for real- time work observation by shore person- nel. Olympic Intervention IV also has 1,600 tons deck capac- ity 10,225 sqftof clear deck, a large working moon pool, two Oceaneering work-class remotely operated vehicles (ROV) , an on-board ROV tooling suite, a 1 50 mt capacity crane with active heave compensation, accommodations for 150 persons, a DNVAUTHR (Class 2) dynamic positioning system, and a helicopter platform capable of landing Super Puma and Sikorsky S61 aircraft.

Fig.