FREMGANGSMAATE FOR NOEYAKTIG INSTALLERING AV EN MARIN DYPVANNSKONSTRUKSJON, SAMT KONSTRUKSJON FOR ANVENDELSE UNDER UTFOERELSE AV FREMGANGSMAATEN.

摘要

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.