Gravity base, jack-up platform - method and apparatus

Patent · Tue May 05 04:00:00 EDT 1981

OSTI ID:5903452

Herrmann, R P; Pease, F T; Ray, D R

The invention relates to an offshore, gravity base, jack-up platform comprising a deck, a gravity base and one or more legs interconnecting the deck and base. The gravity base comprises a generally polygonal shaped, monolithic hull structure with reaction members extending downwardly from the hull to penetrate the waterbed and react to vertical and lateral loads imposed upon the platform while maintaining the gravity hull in a posture elevated above the surface of the waterbed. A method aspect of the invention includes the steps of towing a gravity base, jack-up platform, as a unit, to a preselected offshore site floating upon the gravity hull. During the towing operation, the deck is mounted adjacent the gravity base with a leg or legs projecting through the deck. At a preselected offshore station ballast is added to the gravity base and the platform descends slightly to a posture where the platform is buoyantly supported by the deck. The base is then jacked down toward the seabed and the platform is laterally brought onto station. Ballast is then added to the deck and the reaction members are penetrated into the waterbed to operational soil refusal. Ballast is then ejected from the deck and the deck is jacked to an operational elevation above a predetermined statistical wave crest height.

• Assignee: Offshore Co
• Patent Number(s): US 4265568
• OSTI ID: 5903452
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
42 ENGINEERING
423000 -- Engineering-- Marine Engineering-- (1980-)
DESIGN
NATURAL GAS WELLS
OFFSHORE PLATFORMS
OIL WELLS
WELLS