Riser system for a slacked moored hull floating unit

Abstract

A riser tensioning system with an individual riser unit on an oil or gas platform. The platform has a traveling trolley structure with at least one trolley bearing and a centralizer. The trolley bearing is coupled to at least one guide rail configured to allow vertical movement of said traveling trolley structure. The traveling trolley structure is coupled to a riser collar configured to support a top of the riser. The riser tensioning system has at least one cylinder coupled to the traveling trolley structure on one end and secured on an opposite end such that the cylinder is adapted to push or pull the traveling trolley structure vertically.

1 . A riser tensioning system with an individual riser unit on an oil or gas platform, said riser tensioning system comprising:
 a traveling trolley structure having at least one trolley bearing and a centralizer;   at least one guide rail coupled to said trolley bearing, configured to allow vertical movement of said traveling trolley structure;   at least one cylinder attached to said traveling trolley structure on one end and secured on an opposite end, said at least one cylinder being adapted to push or pull said traveling trolley structure vertically; and   a riser collar coupled to said traveling trolley structure and configured to support a top of the individual riser.   
     
     
         2 . The riser tensioning system recited in  claim 1 , wherein:
 said traveling trolley structure is a beam structure with two trolley bearings on opposite sides of said beam structure;   said riser tensioning system has two guide rails, wherein each guide rail is coupled to a trolley bearing; and   said riser tensioning system has two cylinders, wherein each cylinder is attached to the traveling trolley structure on an end and attached to said guide rail on an opposite end.   
     
     
         3 . The riser tensioning system recited in  claim 1 , wherein:
 said traveling trolley structure is a box structure with two trolley bearings on opposite sides of said box structure;   said riser tensioning system has two guide rails, wherein each guide rail is coupled to two trolley bearings; and   said riser tensioning system has two cylinders attached to the traveling trolley beam on a end and attached to said guide rail on an opposite end.   
     
     
         4 . The riser tensioning system recited in  claim 1 , wherein:
 said traveling trolley structure is a beam structure with two trolley bearings on opposite sides of said beam structure;   said riser tensioning system has two guide rails, wherein each guide rail is coupled to a trolley bearing; and   said riser tensioning system has two cylinders, wherein each cylinder is attached to the traveling trolley structure on a end and attached to a deck beam on an opposite end.   
     
     
         5 . The riser tensioning system recited in  claim 1 , wherein:
 said traveling trolley structure is a box structure with two trolley bearings on opposite sides of said box structure;   said riser tensioning system has two guide rails, wherein each guide rail is coupled to two trolley bearings; and   said riser tensioning system has two cylinders attached to the traveling trolley beam on a end and attached to a deck beam on an opposite end.   
     
     
         6 . The riser tensioning system recited in  claim 1 , wherein:
 said traveling trolley structure has two trolley bearings on a same side of said traveling trolley structure;   said riser tensioning system has a guide rail coupled to said two trolley bearings; and   said riser tensioning system has one cylinder attached to said traveling trolley structure on a end and attached said guide rail on an opposite end.   
     
     
         7 . The riser tensioning system recited in  claim 1 , wherein:
 said traveling trolley structure has two trolley bearings on a same side of said traveling trolley structure;   said riser tensioning system has one guide rail coupled to said two trolley bearings; and   said riser tensioning system has one cylinder attached to said traveling trolley structure on a end and attached to a deck beam on an opposite end.   
     
     
         8 . A riser tensioning system recited in  claim 1 , further comprising:
 at least one second cylinder;   a wire and sheave arrangement coupled to said second cylinder on an end and coupled to the riser tensioning system on an opposite end, wherein said wire and sheave arrangement is adapted to push or pull said traveling trolley structure vertically.   
     
     
         9 . A method for applying tension to an individual riser unit on an oil or gas platform, said platform having a riser with a x-mas tree, a traveling trolley structure with at least one trolley bearing and a centralizer and at least one guide rail coupled to said traveling trolley structure, said method comprising the following step:
 attaching at least one cylinder to said traveling trolley structure and securing the other end of said cylinder, such that actuation of said cylinder effects vertical movement of said traveling trolley structure.   
     
     
         10 . The method recited in  claim 9 , wherein said attaching step comprises:
 attaching two cylinders on one end to said traveling trolley structure, wherein said traveling trolley structure is a beam structure, and attaching an opposite end of each said cylinder to two different guide rails.   
     
     
         11 . The method recited in  claim 9 , wherein said attaching step comprises:
 attaching two cylinders on one end to said traveling trolley structure, wherein said traveling trolley structure is a box structure, and attaching an opposite end of each said cylinder to two different guide rails.   
     
     
         12 . The method recited in  claim 9 , wherein said attaching step comprises:
 attaching two cylinders on one end to said traveling trolley structure, wherein said traveling trolley structure is a beam structure, and attaching an opposite end of each said cylinder to a deck beam.   
     
     
         13 . The method recited in  claim 9 , wherein said attaching step comprises:
 attaching two cylinders on one end to said traveling trolley structure, wherein said traveling trolley structure is a box structure, and attaching an opposite end of each said cylinder to a deck beam.   
     
     
         14 . The method recited in  claim 9 , wherein said attaching step comprises:
 attaching a cylinder on one end to said traveling trolley structure and attaching an opposite end of each said cylinder to said guard rail.   
     
     
         15 . The method recited in  claim 9 , wherein said attaching step comprises:
 attaching a cylinder on one end to said traveling trolley structure and attaching an opposite end of each said cylinder to a deck beam.   
     
     
         16 . The method recited in  claim 9 , further comprising the following steps:
 attaching at least one second cylinder to a wire and sheave arrangement and securing the other end of said cylinder, such that actuation of said cylinder effects vertical movement of said traveling trolley structure.   
     
     
         17 . A riser tensioning system with an individual riser unit on an oil or gas platform, said platform having a traveling trolley structure with at least one trolley bearing and a centralizer, said trolley bearing coupled to at least one guide rail configured to allow vertical movement of said traveling trolley structure, said traveling trolley structure coupled to a riser collar configured to support a top of said riser, said riser tensioning system comprising:
 at least one cylinder attached to the traveling trolley structure on one end and secured on an opposite end such that said cylinder is adapted to push or pull said traveling trolley structure vertically.   
     
     
         18 . The riser tensioning system recited in  claim 17 , wherein:
 said riser tensioning system has two cylinders, wherein each cylinder is attached on an end to the traveling trolley structure, wherein the traveling trolley structure is a beam structure, and attached on an opposite end to a bottom of the guide rail.   
     
     
         19 . The riser tensioning system recited in  claim 17 , wherein:
 said riser tensioning system has two cylinders, wherein each cylinder is attached on an end to the traveling trolley structure, wherein the traveling trolley structure is a box structure, and attached on an opposite end to a bottom of the guide rail.   
     
     
         20 . The riser tensioning system recited in  claim 17 , wherein:
 said riser tensioning system has two cylinders, wherein each cylinder is attached on an end to the traveling trolley structure, wherein the traveling trolley structure is a beam structure, and attached on an opposite end to a deck beam.   
     
     
         21 . The riser tensioning system recited in  claim 17 , wherein:
 said riser tensioning system has two cylinders, wherein each cylinder is attached on an end to the traveling trolley structure, wherein the traveling trolley structure is a box structure, and attached on an opposite end to a deck beam.   
     
     
         22 . The riser tensioning system recited in  claim 17 , wherein:
 said riser tensioning system has one cylinders, wherein each cylinder is attached on an end to the traveling trolley structure and attached on an opposite end to said guard rail.   
     
     
         23 . The riser tensioning system recited in  claim 17 , wherein:
 said riser tensioning system has one cylinders, wherein each cylinder is attached on an end to the traveling trolley structure and attached on an opposite end to a deck beam.   
     
     
         24 . The riser tensioning system recited in  claim 17 , further comprising:
 at least one second cylinder;   a wire and sheave arrangement coupled to said second cylinder on an end and coupled to the riser tensioning system on an opposite end, wherein said wire and sheave arrangement is adapted to push or pull said traveling trolley structure vertically.