Installation of an offshore structure

Patent · Tue Apr 07 04:00:00 EST 1981

OSTI ID:6359019

Will, S A; Young, C E

In the installation of a jacket or substructure component of an offshore platform on the sea floor over an underwater fixture containing one or more wellheads, a jacket is first ballasted to rest in a vertical orientation on the sea floor. Power winches are mounted atop the jacket above the water line and anchored mooring lines are connected to the winches via fairlead sheaves which define points of attachment for the mooring lines to the jacket. The jacket is deballasted to float with a near sea bottom clearance and is maneuvered horizontally with the power winches toward the underwater fixture. Docking guides carried by the jacket engage vertical guideposts driven drilled into the sea floor at preselected locations relative to the underwater fixture to align the jacket with the underwater fixture. The jacket is then lowered into the desired on-bottom position during controlled ballasting procedures. Finally, piles are driven through hollow jacket columns to anchor the jacket to the sea bottom.

• Assignee: J Ray Mcdermott And Co Inc
• Patent Number(s): US 4260291
• OSTI ID: 6359019
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420206* -- Engineering-- Mining & Drilling Equipment & Facilities-- (1980-1989)
423000 -- Engineering-- Marine Engineering-- (1980-)
INSTALLATION
LEVELS
OFFSHORE PLATFORMS
SEAS
SURFACE WATERS
UNDERWATER
WELLHEADS