Inspection/maintenance

Moorings Replacement and Hookup for a Damaged North Sea FPSO

This paper describes the measures put in place so that the mooring system of the Gryphon Alpha FPSO could be replaced and reconnected on an efficient schedule.

jpt-2015-02-fig2moorings1.jpg
Fig. 2—Anchors on deck (Stage 1).

In a North Sea storm during February 2011, the Gryphon Alpha floating production, storage, and offloading (FPSO) unit broke four of its 10 mooring lines and moved partially off station, resulting in damage to subsea assets. Following the incident, the FPSO was taken to dry dock for replacement of the damaged subsea infrastructure and moorings. This paper describes the measures put in place so that the mooring system could be replaced and the FPSO reconnected on an efficient schedule.

The FPSO

In September of 1993, the Gryphon Alpha became the first purpose-built long-term-moored FPSO to be installed in the North Sea. The unit is located 175 miles northeast of Aberdeen in a water depth of 112 m.

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