Claims
- 1. A method for recovering well fluids from a subsea well, which comprises:
- (a) attaching means to the seabed offshore for anchoring tendons to the seabed;
- (b) connecting at least three vertically oriented tendons to the anchor means;
- (c) towing to a location above the vertically oriented tendons a surface buoy which has a surface-piercing central flotation column for supporting one or more decks above the water surface, and submerged flotation tanks connected to the central flotation column by braces below the water surface;
- (d) ballasting the surface buoy to lower it for connection with the tendons while maintaining the upper end of the central flotation column above the water surface;
- (e) securing the tendons to the surface buoy;
- (f) deballasting the surface buoy to place the tendons in tension while supporting one or more decks above the water surface;
- (g) establishing fluid communication between a subsea well and the surface buoy; and
- (h) offloading well fluids to a cargo barge or pipeline.
- 2. The method of claim 1 wherein said subsea well is located in over 300 feet of water.
- 3. The method of claim 1 wherein the tendons are each vertically oriented by a tendon flotation buoy attached near the upper end of each tendon.
- 4. The method of claim 1 wherein the anchor means is attached to the seabed by installing an individual anchoring pile in the seabed for each tendon.
- 5. A production platform for deepwater oil or gas wells comprising:
- (a) a surface buoy having a surface piercing central flotation column, submerged flotation tanks outwardly of the central flotation column and braces between the central flotation column and the tanks;
- (b) a production platform supported by the central flotation column of the surface buoy;
- (c) at least three spaced tendons secured to the seabed and attached to the submerged flotation tanks or braces outwardly from the central column; and
- (d) said surface buoy supporting said production platform while maintaining the tendons in tension.
- 6. The platform of claim 5 wherein the tendons can be released from attachment to the tanks or braces and the platform can be removed and located over other wells.
- 7. A method of providing a stable platform above offshore water, which comprises the steps of:
- (a) attaching means to the seabed offshore for anchoring tendons to the seabed;
- (b) connecting at least three vertically oriented tendons to the anchor means;
- (c) towing to a location near the upper ends of the vertically oriented tendons surface buoy which has a surface-piercing central flotation column for supporting one or more decks above the water surface, and submerged flotation tanks connected to the column by braces below the water surface to provide connections for the tendons outward of the perimeter of the central flotation column;
- (d) ballasting the surface buoy to lower it for connection with the tendons while maintaining the upper end of the central flotation column above the water surface;
- (e) securing the tendons to the tanks or braces outwardly from the central flotation column; and
- (f) deballasting the surface buoy to place the tendons in tension while supporting one or more decks above the water surface.
- 8. A subsea well tender system comprising a surface buoy supporting one or more decks above the water surface for accommodating equipment to process oil, gas, and water, and further including anchor means securing said surface buoy to the seabed, wherein said surface buoy includes a surface-piercing central flotation column and at least one flotation tank mounted to said central flotation column, and wherein said anchor means is attached to individual anchoring piles secured in the seabed.
Parent Case Info
This is a continuation application of U.S. patent application Ser. No. 08/158,921 filed Nov. 29, 1993, now U.S. Pat. No. 5433273, which is a continuation application of U.S. patent application Ser. No. 07/891,953 filed Jun. 1,1992, U.S. Pat. No. 5,297,632, issued Mar. 29, 1994, which is a continuation application of U.S. patent application Ser. No. 07/626,994 filed Dec. 13, 1990, U.S. Pat. No. 5,117,914, issued Jun. 2, 1992.
US Referenced Citations (3)
Continuations (3)
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Number |
Date |
Country |
Parent |
158921 |
Nov 1993 |
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Parent |
891953 |
Jun 1992 |
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Parent |
626994 |
Dec 1990 |
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