FRANCE:

Flexible connections for FPSO and loading buoy export lines

In a project that began in early 2000, Techlam of the SNECMA Group, France, is about to complete delivery of the final items related to the supply of FPSO and loading buoy export line connections for Girassol field, offshore Angola. Installation work is being performed by the AMG Consortium (Stolt Offshore and Bouygues Offshore) for operator TotalFinaElf.

Designed, engineered and manufactured by Techlam, the connections faced several technical challenges, including:

• Severe angles in the 16-in. flex joints – single type: ±21° rotation angle on FPSO side; double flexible element type: ±36° angle on buoy side.
• One flex joint prototype has been fatigue tested successfully in early 2001. It exceeded, by more than 100 times, the normal 20-year operation lifespan, with no failure in the rubber / steel flexible element.
• New type of FPSO and buoy-side steel receptacle, with an integrated pre-tensioning system, is suitable for easy and safe installation operation. This device answers AMG’s request for the installation of the male connector into the receptacle. The male connector, which is welded to the export line, is lifted by a cable through a pulling head. It enters the pre-tensioning device when it is first securely locked by means of four hydraulic jacks. A positive tension load of about 250 tons then is applied through the jacks, and finally maintained with four strong steel struts. Hydraulic jacks are removed and may be reused for dismantling (reverse operation). After removal of the pulling head, the export line is connected to the FPSO and/or buoy through an upper swivel flange.

The FPSO receptacles and buoy-side structures have been delivered to the Korea FPSO yard and to Lobito Angola Sonamet facilities, respectively, for welding integration.

An FPSO side fit-up test currently is being successfully implemented in Korea with a mock-up of the male connector / flex joint assembly in order to simulate an installation operation and to test the pre-tensioning device.

The delivery of the six rubber steel flexible elements and assembly of the four flex joints / male connectors is scheduled for May 2001. Installation in Girassol field is planned for the third quarter of 2001.

FPSO-side flex joint connection that is being used by TotalFinaElf for its Girassol field offshore Angola.

This flexible connection system is suitable for any type of oil and gas flow-line, including:

• Export lines from an FPSO to a loading buoy
• Production, injection and export SCRs (steel catenary risers), connected to an FPSO, TLP or semisubmersible floater.

Within the scope of the production-sharing agreement covering Block 17, SONANGOL (Sociedade National de Combustiveis de Angola) is the concessionaire, and TotalFinaElf-E&P Angola is the operator for the following partners: TotalFinaElf-E&P Angola (40%); Esso Exploration Angola (Block 17) Ltd. (20%); BP Exploration Angola Ltd. (16.67%); Den Norsk Stats Oljeselskap a.s. (13.33%); and Norsk Hydro ASA (10%).