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US 6,585,455 B1Granted
Rocker arm marine tensioning system
AssigneeShell Oil Company
InventorsWilliam Henry Petersen, Robert Wayne Patterson
Life of this patent
Estimating the term…
Abstract
A tensioning riser system for supporting marine elements such as risers which extend form a fixed lower end at a subsea base or foundation to a moving, floating superstructure. The tensioning system has a lever arm pivotally connected to both the superstructure and the upper end of the marine element and a tension controlling strut member pivotally connected to both the superstructure and the lever arm.
Claims60
A tensioning system for directly supporting a marine element which extends from a fixed lower end at a subsea base to an upper end presented at a moving superstructure of a floating platform, said tensioning system comprising:
- a lever action rocker arm pivotally connected both directly to the superstructure and to the upper end of the marine element;
- and
- a tension controlling strut member pivotally connected both directly to the superstructure and to the rocker arm;
- whereby said tension system is the direct, primary motion compensation between the marine element and the moving superstructure of the floating platform.
1 more element
A marine tensioning system for directly supporting an elongated marine element which extends from a fixed lower end at a subsea base to an upper end presented at a moving, floating superstructure, said tensioning system comprising:
- a lever action rocker arm pivotally connected to the superstructure at a fulcrum connection and to the upper end of the marine element at a load connection spaced a distance L1 from the fulcrum connection;
- a tension controlling strut member comprising:
- an elongated strut;
- a first strut connection pivotally attaching the strut to the superstructure;
- a second strut connection pivotally attaching the strut to the rocker arm at a position spaced a distance L2 on the rocker arm from the fulcrum connection such that distance L1 exceeds distance L2;
- a tension controller within the strut between the first and second strut connections, said tension controller comprising a pressure charged elastomeric spring.
3 more elements
A riser tensioning system for directly supporting a riser which extends from a fixed lower end at a subsea base to a moving superstructure, said riser tensioning system comprising:
- a lever action rocker arm, comprising:
- a plurality of elongated lever arms;
- a fulcrum connection pivotally attaching the rocking arm to the moving superstructure;
- and
- a load connection spaced apart from the fulcrum connection on the rocking arm and pivotally attaching the rocking arm to the riser;
- and
- a tension controlling strut member, comprising:
- an elongated strut:
- a first strut connection pivotally attaching the strut to the moving superstructure;
- a second strut connection pivotally attaching the strut to the lever arm at
- a position spaced apart from the fulcrum;
- and
- a tension controller within the strut member between the first and second strut connections.
10 more elements
A riser tensioning system for directly supporting a marine riser which extends from a fixed lower end at a subsea base to a moving superstructure, said marine riser tensioning system comprising:
- a lever action rocker arm, comprising:
- at least one elongated lever arm:
- a fulcrum connection pivotally attaching the rocking arm to the moving superstructure;
- and
- a load connection pivotally connecting the marine riser to the rocking arm;
- a tension controlling strut member, comprising:
- an elongated strut;
- a first strut connection pivotally connecting the strut to the moving superstructure at a position below the fulcrum connection;
- a second strut connection pivotally connecting the strut to the lever arm at a position on the rocking arm between the fulcrum connection and the load connection;
- and
- a tension controller between the first and second strut connections, comprising a pressure charged elastomeric spring.
8 more elements
A method for supplying tension to a marine element across a direct connection between the marine element and a superstructure in relative motion therewith, said method comprising:
- pivotally connecting a lever arm to both the superstructure and the marine element;
- pivotally connecting a tension controlling member to both the superstructure and the lever arm;
- and
- applying a controlled force to the lever arm, and thereby the marine element, through the tension controlling member.
1 more element
A method for tensioning a marine riser which extends from a fixed lower end at a subsea base to an upper end at a moving superstructure of a platform which is subjected to the surface action of the ocean, said method comprising:
- pivotally connecting a rocker arm directly to the moving superstructure and to the marine riser;
- and
- operably connecting a tension controlling member to both the superstructure and the rocker arm in such a manner as to allow rotation of the rocker arm at a substantially constant tension in response to a relative motion between the superstructure and the marine riser;
- pivotally connecting a lever arm to both the superstructure and the marine element;
- pivotally connecting a tension controlling member to both the superstructure and the lever arm;
- and
- applying a controlled force to the lever arm, and thereby marine element, through the tension controlling member.
4 more elements
A method for installing a riser tensioning system on a floating superstructure, comprising:
- lifting a rocker arm with at least a first tension controlling strut member to a selected well slot the at least first tension controlling strut member being connected to the rocker arm through a pivoting rocker arm hinge connection on one end and having a pivoting strut base connection including a shoe depending from the other end;
- temporarily securing the shoe of the tensioning controlling strut member at a first position on a ramp supported by the superstructure;
- aligning and making up a fulcrum connection pivotally joining the rocker arm to the superstructure;
- and
- drawing the shoe up the ramp from the first position and securing the shoe to the ramp at a second position, elevated with respect to the first position to complete the strut base connection and preload a tension controller within the tension controlling strut member.
2 more elements
A riser tensioner system for applying a tensioning force to a riser and allowing a floating platform to move within a preselected range along a longitudinal axis of said riser, said system comprising:
- a spring and a lever forming an assembly, said assembly being coupled to said riser and to said platform, said spring having a spring rate, said lever being coupled to said spring to control orientation of said spring relative to said riser in response to relative movement between said platform and said riser along said longitudinal axis, thereby controllably varying a magnitude of a vertical component of said spring rate in proportion to said relative movement such that said tensioning force remains substantially constant through said range.
A riser tensioner system for applying a tensioning force to a riser and allowing a floating platform to move within a preselected range along a longitudinal axis of said riser, said system comprising:
- a spring having a first end and a second end, said first end being pivotally coupled to said floating platform, said spring having a preselected spring rate;
- a lever having a first end and a second end, said first end of said lever being pivotally coupled to said floating platform, and said second end of said lever being pivotally coupled to said riser;
- said second end of said spring being pivotally coupled to a preselected location on said lever, thus forming an angle between a longitudinal axis of said spring and the longitudinal axis of said riser, said angle determining a vertical magnitude of said spring rate;
- said lever varying said vertical magnitude of said spring rate in proportion to movement of said platform so that said tensioning force remains substantially constant through said range.
1 more element
The system, as set forth in claim rein each of said levers comprises:
- a plurality of first arms, each of said first arms having a first end and a second end, said first end of each of said first arms being pivotally coupled to said platform and said second end of each of said first arms being pivotally coupled to said riser;
- and
- a plurality of second arms, each of said second arms having a first end and a second end, said first end of each of said second arms being pivotally coupled to said platform and said second end of each of said second arms being pivotally coupled to said first arms.
A riser tensioner system containing:
- a first spring having a first end and a second end, said first end being pivotally coupled to a riser and forming a first angle between a longitudinal axis of said first spring and a longitudinal axis of said riser;
- a second spring having a first end and a second end, said first end of said second spring being pivotally coupled to said second end of said first spring to form a junction, and said second end of said second spring being pivotally coupled to a floating platform and forming a second angle between a longitudinal axis of said second spring and said longitudinal axis of said riser;
- a lever having a first end and a second end, said first end of said lever being pivotally coupled to said floating platform, and said second end of said lever being pivotally coupled to said junction;
- said first and second springs being adapted to increasingly compress in response to said platform moving relatively to said riser along said longitudinal axis of said riser in a first direction, whereby movement in said first direction causes said first and second angles to increase;
- and
- said first and second springs being adapted to decreasingly compress in response to said platform moving relatively to said riser along said longitudinal axis of said riser in a second direction, whereby movement in said second direction causes said first and second angles to decrease.
3 more elements
A method for applying a tensioning force to a riser while allowing limited movement between the riser and a floating platform, comprising the steps of:
- pivotally coupling a first end of a first compression spring to said riser and forming a first angle between a longitudinal axis of said first compression spring and a longitudinal axis of said riser, said first compression spring having a first spring rate having a vertical magnitude being determined by said first angle;
- pivotally coupling a second end of said first compression spring to a first end of a second compression spring to form a junction and to form a second angle between a longitudinal axis of said second compression spring and said longitudinal axis of said riser, said second compression spring having a second spring rate having a vertical magnitude being determined by said second angle;
- pivotally coupling a second end of said second compression spring to said platform;
- and
- pivotally coupling a first end of a lever to said platform;
- pivotally coupling a second end of a lever to said junction;
- and
- decreasing said vertical magnitude of said first and second spring rates in proportion to said movement by increasing said first and second angles when said movement causes said respective first and second springs to compress so that said tensioning force remains substantially constant.
5 more elements
A method for applying a tensioning force to a riser while allowing limited movement between the riser and a floating platform, comprising the steps of:
- pivotally coupling a first end of a lever to said platform;
- pivotally coupling a second end of said lever to said riser;
- pivotally coupling a first end of a compression spring to said platform and forming an angle between a longitudinal axis of said compression spring and a longitudinal axis of said riser, said compression spring having a spring rate having a vertical magnitude being determined by said angle;
- and
- pivotally coupling a second end of said compression spring at a preselected location on said lever so that vertical movement in a first direction between said riser and said platform causes said compression spring to increasingly compress and said angle to increase.
2 more elements
A method for applying a tensioning force to a riser while allowing limited movement between the riser and a floating platform, comprising the steps of:
- pivotally coupling first ends of a plurality of levers to said platform;
- pivotally coupling second ends of said plurality of levers to said riser;
- pivotally coupling first ends of a like plurality of compression springs to said platform and forming an angle between a longitudinal axis of each of said compression springs and a longitudinal axis of said riser, each of said compression springs having a spring rate having a vertical magnitude being determined by said respective angle;
- and
- pivotally coupling second ends of said plurality of compression springs at a preselected location on said respective levers, whereby movement in a first direction between said riser and said platform causes each of said compression springs to increasingly compress and each of said angles to increase.
2 more elements
A riser tensioner system for applying a tensioning force to a riser and allowing a floating platform to move within a preselected range along a longitudinal axis of said riser, said system comprising:
- a spring assembly being adapted for coupling said riser to said platform and having a preselected spring rate, said assembly being configured for varying a magnitude of a vertical component of said spring rate in proportion to movement of said platform such that said tensioning force remains substantially constant throughout said range, wherein said spring assembly comprises:
- a first spring having a first end and a second end, said first end being pivotally coupled to said platform and said second end being pivotally coupled to said riser;
- and
- a second spring having a first end and a second end, said first end of said second spring being pivotally coupled to said platform at a location below said first end of said first spring and said second end of said second spring being pivotally coupled to said riser.
1 more element
A riser tensioner system for applying a tensioning force to a riser and allowing a floating platform to move within a preselected range along a longitudinal axis of said riser, said system comprising:
- spring means for providing said tensioning force, said spring means having a predetermined spring rate and being coupled to said platform and to said riser;
- and
- lever means for controllably varying a vertical component of said predetermined spring rate by controlling orientation of said spring means relative to said riser in response to relative movement between said riser and said platform along said longitudinal axis, said lever means being coupled to said spring means and to at least one of said riser and said platform.
A riser tensioner system for applying a tensioning force to a riser and allowing a floating platform to move within a preselected range along a longitudinal axis of said riser, said system comprising:
- spring means for providing said tensioning force, said spring means having a predetermined spring rate and being coupled to at least one of said platform and said riser;
- and
- lever means for controllably varying a vertical component of said predetermined spring rate by controlling orientation of said spring means relative to said riser in response to relative movement between said riser and said platform along said longitudinal axis, said lever means being coupled to said spring means and to said riser and said platform.
A riser tensioner system for applying a tensioning force to a riser and allowing a floating platform to move within a preselected range along a longitudinal axis of said riser, said system comprising:
- a plurality of springs and a plurality of levers forming a plurality of assemblies, said assemblies being coupled to said riser and to said platform, each said spring having a spring rate and remaining in compression throughout said preselected range of motion, each of said levers being coupled to a respective spring and to at least one of said riser and said platform to control orientation of said respective spring relative to said riser in response to movement between said platform and said riser along said longitudinal axis said lever being coupled to said spring to control orientation of said spring relative to said riser in response to relative movement between said platform and said riser along said longitudinal axis, thereby controllably varying a magnitude of a vertical component of said spring rate in proportion to said relative movement such that said tensioning force remains substantially constant through said range.
A riser tensioner system for applying a tensioning force to a riser and allowing a floating platform to move within a preselected range along a longitudinal axis of said riser, said system comprising
- a plurality of springs each having a first end and a second end and each spring having a preselected spring rate, said first end of each spring being pivotally coupled to said floating platform;
- a plurality of levers each having a first end and a second end, said first end of each lever being pivotally coupled to said floating platform, and said second end of each lever being pivotally coupled to said riser, each lever having a plurality of first arms, each of said first arms having a first end and a second end, said first end of each of said first arms being pivotally coupled to said platform and said second end of each of said first arms being pivotally coupled to said riser;
- said second end of each spring being pivotally coupled to a preselected location on one of said respective levers, thus forming an angle between a longitudinal axis of said spring and the longitudinal axis of said riser, said angle determining a vertical magnitude of said spring rate for said respective spring;
- each lever varying said vertical magnitude of said spring rate of said respective spring in proportion to movement of said platform so that said tensioning force remains substantially constant through said range;
- and
- a plurality of motion compensation bearings being pivotally coupled to said riser, each of said bearings being slidably coupled to one of said second ends of said plurality of respective levers.
3 more elements
A riser tensioner system containing:
- a first spring having a first end and a second end, said first end being pivotally coupled to a riser and forming a first angle between a longitudinal axis of said first spring and a longitudinal axis of said riser;
- a second spring having a first end and a second end, said first end of said second spring being pivotally coupled to said second end of said first spring to form a junction, and said second end of said second spring being pivotally coupled to a floating platform and forming a second angle between a longitudinal axis of said second spring and said longitudinal axis of said riser;
- a lever having a first end and a second end, said first end of said lever being pivotally coupled to said floating platform, and said second end of said lever being pivotally coupled to said junction;
- said first and second springs being adapted to increasingly compress in response to said platform moving relatively to said riser along said longitudinal axis of said riser in a first direction, whereby movement in said first direction causes said first and second angles to increase;
- and
- said first and second springs being adapted to decreasingly compress in response to said platform moving relatively to said riser along said longitudinal axis of said riser in a second direction, whereby movement in said second direction causes said first and second angles to decrease.
3 more elements
A riser tensioner system for applying a tensioning force to a riser and allowing a floating platform to move within a preselected range along a longitudinal axis of said riser, said system comprising:
- a spring assembly being adapted for coupling said riser to said platform and having a preselected spring rate, said assembly being configured for varying a magnitude of a vertical component of said spring rate in proportion to movement of said platform such that said tensioning force remains substantially constant throughout said range, wherein said spring assembly comprises:
- a first spring having a first end and a second end, said first end being pivotally coupled to said platform and said second end being pivotally coupled to said riser through a lever arm;
- and
- a second spring having a first end and a second end, said first end of said second spring being pivotally coupled to said platform at a location below said first end of said first spring and said second end of said second spring being pivotally coupled to said riser through a lever arm.
1 more element
Dependencies are inferred from the claim text.