King Field, Gulf of Mexico, USA

For the first time, innovative subsea boosting technology will increase production in the Gulf of Mexico from wells on the King field. Located in a water depth of 1,700m, it is the deepest such installation to date. It also lies 29km from the host platform, making it the longest booster subsea tieback to date. It stands as the first commercial application of this technology.

King is spread across Mississippi Canyon blocks 84, 85, 128, 129. It is operated by BP, which has 100% equity of the project. The water depth at the field varies between 1,600m and 1,800m (5,000ft to 5,400ft).

KING FIELD DEVELOPMENT

Initial field development plans were carried out by Amoco before it was subsumed into BP. The development was going to be carried out in association with the King's Peak field, based on five subsea wells producing through 6in and 10in Pipe-In-Pipe (PIP) insulated flowlines and tied back to a truss spar production system.

It was also going to include water injection facilities via 6in and 8in flowlines and steel catenary risers to three subsea water injection wells. Processed wellstream, from the spar was to be exported via two 16in pipelines to a gathering system tie-in points at Main Pass 225 and Main Pass 260.

Affected by the oil price, the field underwent a development reappraisal. King is now one of three fields producing from the Marlin TLP and represents more than half of Marlin TLP production. The complex lies 18 miles from Marlin in the Viosca Knoll area, approximately 84 miles southeast of New Orleans.

In late 2007, the project to retrofit two existing subsea wells with the innovative subsea booster pump to optimise oil recovery will commence. This will mark the first subsea multi-phase pump application in water depths greater than 3,000ft.

KING FIELD CONTRACTS

The contract to supply the pumping system was won by Aker Kvaerner Subsea. In total, Aker Kvaerner supplied three systems (for two subsea pump stations plus one spare) at a total value of NKr220m.

The total contract includes modules with manifolds, variable speed drives, topside and subsea control systems, topside lube oil and hydraulic power units, and high voltage connectors and jumpers. The pump station systems were manufactured at Aker Kvaerner Subsea's facility in Tranby, Norway.

SUBSEA SERVICE UMBILICAL

BP awarded industrial cable supplier Nexans the $15m contract by for the design and manufacture of the world's first subsea service umbilical that integrates a High-Voltage (HV) cable rather than having to resort to separate umbilical and power cables.

The deep water 16-mile-long power umbilical will consist of a main dynamic and an infield umbilical. Apart from low- and high-voltage electrical power, the umbilical will also provide oil for the pump lubrication, chemicals for injection to prohibit the formation of hydrates and fibre-optic communications. The conductor to the booster system will carry 24,000V.

In all, three wells will be boosted – D6, D5 and D3. Of the six-core power umbilical three of the cores run to D5 and D3 while the remaining three continue to D6.

The booster assembly consists of a manifold base skid supporting the pump module itself. Each of the 70t assemblies were located over 3.6m-diameter suction piles.

The design specifies MPC-335-50 Bornemann pumps, which can pump at 75,000bpd and give a 50bar differential pressure. Inlet pressures at the King wells range from 48bar to 127bar.

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