Ocean Legend Conversion

Oceaneering was awarded a time-charter contract in November 1999 by Woodside Energy and its partners to provide a jackup MOPS unit (JPU) for development of the Legendre fields on Western Australia's North West Shelf. Under the contract, which has a primary term of three years, Oceaneering converted its jackup Marine 7 to the JPU Ocean Legend for production service. The conversion took place at Friede and Goldman Offshore, Pascagoula, Miss. Oceaneering is scheduled to install the JPU at Legendre field in December 2000 and will operate it for the contract period. The conversion, transport and installation of the MOPU have an estimated capital cost of approximately $80 million.

Major elements of the conversion workscope included:

• Total refurbishment and repair of the hull and mat structures
• Repair and refurbishment of the tubular legs and jacking system
• Reconfiguration of the previously telescoping legs to eliminate the telescoping feature and provide concentric dual tubulars over the entire leg length
• Installation in the slot area of wellhead and workover decks and a guide frame and tensioning system for well conductors
• Refurbishment and upgrading of marine and utility systems and the accommodations. Procurement and installation of a production process system with the following capacities:
  • 55,000 bpd oil
  • 64,000 bfpd total fluids
  • 39 mmscfd gas reinjection
  • 20 mmscfd gas lift
  • 60 mmscfd emergency gas flaring
  • Procurement and installation of a helideck
  • Installation of SubMar concrete mats around the lower perimeter of the foundation mat to prevent scour.

Oceaneering performed all conceptual engineering for the conversion, developed budgets and schedules, and specified and procured topside equipment. Oceaneering also provided all project management, including budget and schedule control, interface management, quality assurance and EHS programs. Oceaneering bears primary responsibility for the dry transport of the JPU to Australia, its installation at Legendre field, commissioning of the various systems and production startup.

The Ocean Legend is based on the former Marine 7, the largest mat-supported jackup ever built with a depth rating of 377 ft. This depth capability is not needed in the 160-ft waters at Legendre, and the original leg length is being reduced accordingly. Each of the converted unit's three legs consists of concentric inner and outer tubular sections joined at a 15-ft-dia cast y-ring located in the mat. The inherent strength of the jackup's original design, enhanced by conversion upgrades, will allow the unit to resist severe cyclonic storms that frequent the North West Shelf. And the large original deck area, augmented during conversion, provides sufficient platform space for the extensive production facilities.

Feasibility studies and conceptual engineering for the conversion began in late 1998, with preliminary engineering starting in mid-1999. After the Legendre partners committed to the project at the end of September 1999, specifications for long lead-time equipment were completed, and the unit entered the shipyard in early December. Deck equipment remaining from the unit's drilling days was quickly removed and the tubular legs were dismantled. The hull and mat were then separated and picked up by a floating drydock. This methodology provided complete access to all areas and allowed repairs and refurbishment to proceed on all major structural components simultaneously.

The mat and hull were reunited in early July 2000, completing the drydock portion of the conversion and setting the stage for installation of the oil and gas processing and compression equipment modules. The legs were reassembled as the sections became available. Structural work and equipment installation were essentially complete by mid-October, setting the stage for jacking and incline tests before preparation of the unit for dry-tow to Australia aboard a heavy-lift transport vessel.

The Ocean Legend conversion was performed to very high standards for environmental health and safety (EHS) and quality assurance (QA). Risk assessment and hazard identification reviews were a continuous part of design engineering. A formal hazardous operations (Hazop) review was performed before production process and utility systems designs were finalized. Under Oceaneering's ISO-9001 certified QA system, all conversion project documents were tightly controlled using Agile-based software. This process ensured the accuracy of all drawings released for construction and created clear traceablity for all procured equipment.

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