SeaStar TLP Motion Characteristics

Vertically moored SeaStar TLPs exhibit excellent dynamic behavior compared with free-floating structures, such as spars, which are laterally moored or taut-leg moored. TLPs are vertically moored, using engineered tubular steel tendons. Horizontal motion of a TLP is constrained by the restoring forces of the buoyant hull and the tendons. The axial stiffness of the tendons also reduces the system's vertical natural period to a level much less than the dominant wave energy period. As a result, vertical heave, roll, and pitch motions of a SeaStar TLP are virtually nonexistent, providing several important advantages:

• Personnel comfort and safety are increased
• Problems with drilling equipment and process equipment that is sensitive to motion are minimized. In their first two years of operation, Morpeth and Allegheny endured one direct hit by a hurricane, two hits by named tropical storms, and two winter seasons, yet operators reported uptime to be higher than 98 percent.
• Design criteria for hull interface with top-tensioned production risers and catenary risers are greatly simplified

• Field Development Scenarios
  Dry trees, wet trees, FPSOs, and more
• Anatomy of a SeaStar TLP
  A look at an installed SeaStar TLP
• Optimum Motion
  No heave, pitch or roll
• Hull Scalability
  Match deck loads up to 40,000 tons
• Hull Modularity
  Streamlined, economical fabrication
• Hull Efficiency
  Less steel, lower cost
• SeaStar TLP Tendons
  The tension in tension-leg platform
• SeaStar TLPs for Ultra-Deepwater
  Motion damping extends capability to 10,000 ft
• Installation without a Derrick Barge
  No costly heavy lift offshore
• Project Summaries
  Morpeth, Allegheny, Typhoon, Matterhorn