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Usan FPSO

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"Usan FPSO", under construction.
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"Usan FPSO", under construction.
( Copyright reserved )
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"Usan FPSO", under construction.
( Copyright reserved )
 photo UsanFPSO-3_zps21b09498.jpg
"Usan FPSO", under construction.
( Copyright reserved )
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"Usan FPSO", gets underway.
( Copyright reserved )

Deepwater Usan FPSO development off Nigeria scores oil
By : Gene Kliewer
Technology Editor, Subsea & Seismic

Total, then operator of deepwater block OML 138 offshore Nigeria, started first production from Usan field in February 2012. Usan water depths range down to 850 m (2,788 ft). The development, 100 km (62 mi) offshore, consists of an FPSO initially to 42 development wells (23 producing and 19 water and gas injectors) connected by subsea flowlines.

At 320 m (1,050 ft) long by 61 m (200 ft) wide, the FPSO Usan is one of the largest in the world and can process 180,000 b/d of oil, 5 MMcm/d (176.6 MMcf/d) of gas, and store 2 MMbbl.

Total E&P Nigeria Ltd. sold its 20% interest in OML 138 to Sinopec earlier this month. Nigerian National Petroleum Corp. (NNPC) remains the concession holder. The other partners are Chevron Petroleum Nigeria Ltd. (30%), Esso E&P Nigeria (Offshore East) Ltd. (30%), and Nexen Petroleum Nigeria Ltd. (20%).

Hyundai Heavy Industries (HHI) won a $1.6-billion award from Elf Petroleum Nigeria to build the FPSO on a turnkey basis, from the engineering, procurement, and construction to the test runs. Construction began in 2008, the launch was in November 2010, and the vessel arrived at the field in July 2011.

HHI awarded Nexans a $9.4-million contract to manufacture and supply cables for the Usan field FPSO. Nexans' Kukdong factory in South Korea manufactured more than 1,700 km (1,056 mi) of power, control, instrumentation, and telecommunications cable for the project. Rated from 1 kV up to 30 kV, the low-voltage and medium-voltage power cables comply with the latest international standards. Nexans will also provide cables with different insulation types (ERP or XLPE) and armor protections (galvanized steel wire braid or copper wire braid).

FPSO Design Capacity
Stabilised condensate (average)
Stabilised condensate (max)
Total fluids
Produced gas
Injected gas
Fuel gas
Exported gas
Injected water
Produced water
Crude Storage

FPSO Characteristics
Design life 20 years,
Max POB 240 (sleeping capacity 220)
Total topsides net dry weight 27,000te (incl accommodation module)
Hull dimensions 310 x 61 x 31 m,
Hull net dry weight 51,000 te,
Hull designed for deadweight 305,000 te
Total displacement 410,000 te
Double hull design 15 tanks (13 condensate, 2 x ballast),
Separation 4 stages (80, 24, 9 & 2 bara),
Separators 2 x 1st stage + test separator,
Power generation 120 MW (5 x 24 MW {(dual fuel} + 1 spare),
Power loads 86 MW (63 MW without gas export),
Riser slots 40
Spare slots 18 of which 6 SCR