Method and apparatus for tensioning a riser

Patent · Tue Nov 29 04:00:00 EST 1988

OSTI ID:6436790

Myers, R J; Delgado, J H

This patent describes a tensioner system for tensioning a riser from a producing subsea well and for compensating for relative movement between the riser and a production platform, the riser having a longitudinal axis, the apparatus comprising: at least three riser tensioners interconnected between the platform and the riser, each tensioner comprising a piston cylinder arrangement with a rod-mounted piston slidably mounted therein; a tensioner ring surrounding a portion of the riser and having attachment points for connecting the tensioners at a first radial distance from the riser, and plurality of attachment points being equal in number to the plurality of tensioner; means for securing the tensioner ring to the riser; means for pivotally attaching an end of each of the tensioners to one of the attachment points; means for pivotally attaching a second end of each of the tensioners to the platform at a point above the tensioner ring at a second radial distance greater than the first; whereby the piston cylinders, with the piston rods in their median position, act along force lines which define a first angle with respect to the riser and which pass through a common point lying along the longitudinal axis of the riser such that failure of one of the tensioners will not result in torsional forces being applied to the riser by the tensioner system.

• Assignee: Conoco Inc., Ponca City, OK
• Patent Number(s): US 4787778
• OSTI ID: 6436790
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
CYLINDERS
DESIGN
INSTALLATION
MARINE RISERS
MECHANICAL STRUCTURES
NATURAL GAS WELLS
OFFSHORE PLATFORMS
OIL WELLS
PIPES
PISTONS
POSITIONING
RESTRAINTS
SUPPORTS
TOOLS
WELLS