Corrosion resistant tension leg cables
AssigneeConoco Inc.
InventorFrederick J. Radd
Life of this patent
Estimating the term…
Abstract
A tension leg cable is connected between a floating structure and a seafloor anchor means. The cable is a multi-strand cable having voids between adjacent strands. A fluid tight vulcanized rubber sheath is provided covering an outer surface of the cable. A fluid tight corrosion resistant tubular member surrounds said sheath so as to define an annular space between the tubular member and the sheath. Means is provided for supplying an inert gas under pressure to said voids and said annular space. Means is provided for monitoring the pressure of said inert gas in said voids and said annular space to detect changes in said pressure so as to indicate a leak in either said sheath or said tubular member. Methods of construction of said tension leg cable are also disclosed.
Claims20
A mooring system apparatus for a structure floating on a body of water, comprising:
- a corrosion resistant cable system, including:
- a multi-strand cable, having voids between adjacent strands;
- a fluid tight covering engaging an outer surface of said cable;
- a means for supplying fluid under pressure directly to said voids;
- and
- a fluid pressure monitoring means, for continuously monitoring said fluid pressure in said voids and determining when said fluid pressure in said voids changes;
- a first connector means, connected to an upper end of said cable, for connecting said cable to said floating structure;
- and
- a second connector means, connected to a lower end of said cable, for connecting said cable to an anchor means attached to a floor of said body of water.
A mooring system apparatus for a structure floating on a body of water, comprising:
- a corrosion resistant cable system, including:
- a multi-strand cable, having voids between adjacent strands;
- a fluid tight covering engaging an outer surface of said cable;
- a means for supplying fluid under pressure to said voids;
- and
- a fluid pressure monitoring means, for determining when said fluid pressure in said voids changes;
- a first conector means, connected to an upper end of said cable, for connecting said cable to said floating structure;
- a second connector means, connected to a lower end of said cable, for connecting said cable to an anchor means attached to a floor of said body of water;
- a fluid tight tubular member, within which said covering is received;
- a means for supplying fluid under pressure to a space between said tubular member and said covering;
- and
- a means for determining when said fluid pressure in said space changes.
A tension leg platform mooring system, comprising:
- a floating structure;
- a seafloor anchor;
- a tension leg cable connected between said floating structure and said seafloor anchor, said cable being a multi-strand cable having voids between adjacent strands;
- a fluid tight vulcanized rubber sheath covering said cable;
- a means for supplying an inert gas under pressure directly to said voids;
- and
- a means for continuously monitoring said gas pressure in said voids and determining when said gas pressure in said voids changes to indicate a leak in said sheath.
A tension leg platform mooring system, comprising:
- a floating structure;
- a seafloor anchor;
- a tension leg cable connected between said floating structure and said seafloor anchor, said cable being a multi-strand cable having voids between adjacent strands;
- a fluid tight vulcanized rubber sheath covering said cable;
- a means for supplying an inert gas under pressure to said voids;
- a means for determining when said gas pressure in said voids changes, to indicate a leak in said sheath;
- a fluid tight corrosion resistant tubular member, surrounding said sheath;
- a means for supplying inert gas under pressure to a space between said tubular member and said sheath;
- and
- a means for determining when said gas pressure in said space changes, to indicate a leak in said covering.
A method of mooring a tension leg platform, said method comprising the steps of:
- connecting a cable between a floating structure and a seafloor anchor means, said cable including a plurality of strands with voids between adjacent strands and a fluid tight sheath surrounding said plurality of strands;
- supplying an inert gas under pressure directly to said voids between said adjacent strands of said cable;
- and
- continuously monitoring said gas pressure in said voids to detect any leaks in said sheath.
Dependencies are inferred from the claim text.