Gulf of Mexico Blocks VK 825 & 826

Landmark: World’s First Production Spar

Project Overview

• Contract Award: 1996 (Surface)
• 1998 (Subsea)
• Sales: Houston, Texas
• Fabrication: Houston, Texas
• Service Base: Houston, Texas
• Host Type: Spar
• Contract Type: EPC

Project Characteristics

• No. Trees: 13 + 1 Spare (Surface)
• 3 (Subsea)
• Water Depth: 590 m (1,940 ft)
• Tree Type: Vertical
• Tree Pressure: 6,650 psi, 10,000 psi
• Tree Bore Size: 3" (Surface)
• 4"x2" (Subsea)
• Hydrocarbon: Oil/Gas

Project Ownership

• Kerr-McGee 50%
• Dominion 50%

Scope of Work

Surface

• Thirteen (13) + one (1) spare production-riser systems
  • 9-5/8"x3-1/2"x1.900" 6,650 psi risers
  • Subsea wellhead and internal hydraulic connectors
  • Stress-joint interface design
  • Stress-joint integration and testing
  • Engineering and offshore installation
    
• Thirteen (13) + one (1) spare surface wellheads/trees
  • Stem heads and riser load measurement cells
  • Adjustable tension hanger
  • Wellhead access platform
  • Blowout preventer riser
  • Coiled tubing riser
  • Engineering and offshore installation

Subsea

• Three (3) vertical 4"x2" 10,000 psi subsea trees
• One (1) four-slot cluster manifold
• Manifold header pipes welded to flowlines
• Hydraulically operated pigging valves
• Hydraulically operated valves allowing wells to produce to either one of the two flowlines

Comments

Kerr-McGee Neptune Field is located in Viosca Knoll Blocks 825 and 826, 220 km (135 miles) southeast of New Orleans in the Gulf of Mexico. The water depth ranges from 360 m to 980 m (1,200 ft to 3,220 ft) in the southeast corner of Block 870. To develop the field, Kerr-McGee used the world’s first production spar as a base for well production operations.

On the sea floor, the wells are arranged in two (2) parallel rows, which are 32 m (105 ft) long and separated by 6 m (20 ft), so that the wells are spaced 4.6 m (15 ft) apart in one direction and 6 m (20 ft) in the other. Adjusting the mooring lines allowed the spar to be positioned so that the riser was between the rows while the riser was being run. The oil is exported by six (6) oil transfer pumps, each rated at 6,000 bopd. Its two (2) compressors can deliver 30 mmcf/d natural gas, at 1,700 psi, to the pipeline. The oil and gas are exported by separate 8" lines, 17.5 km (11 miles) to the north, to the CNG new fixed platform on Main Pass Block 225.