US 5,252,004 A · Rod accumulator riser tensioning cylinder assembly

Abstract

A "rod accumulator" riser tensioning cylinder assembly for use with off-shore production and exploratory drilling facilities. The tensioner is basically a hydro-pneumatic spring having a tubular cylinder equipped with a hollow rod containing sufficient volume to act as an accumulator. The rod is internally ported to the annulus of the cylinder. The cylinder exterior is coated with a material that will insulate the unit when exposed to high temperature and flame. A wear sleeve is supplied over the insulation material to provide a low friction surface for an outer, cylindrically shaped rod insulation jacket to slide over the cylinder when the rod is stroked into the cylinder. When the rod is stroked out, the jacket is also extended, protecting the rod from flame and high temperature due to its insulative properties. This is a low mass and low volume system, with low lateral area so that an increased number of such cylinder assemblies can be provided in a given horizontal area.

Claims17

Dependent claims

A riser tensioner cylinder assembly which comprises:

a tubular cylinder having an open first end and a closed second end;
a hollow piston rod positioned within said cylinder and adapted to slide inwardly and outwardly of said open first end;
said hollow rod adapted to contain a liquid and a gas under pressure;
the outer surface of said rod spaced from the inner surface of said cylinder to provide an annular space therebetween;
first seal means secured to the inner surface of said cylinder adjacent to said open end of said cylinder adapted to slidably seal against said outer surface of said rod;
second seal means secured to the outer surface of said rod extending into said cylinder, adapted to slidably seal against said inner surface of said cylinder;
and
at least one opening through the hollow rod wall communicating between said annular space and the interior of said hollow rod adjacent to said second seal means;
whereby a pressurized fluid within said hollow rod will act to resist withdrawal of said rod from said cylinder and to move said rod toward a position fully inserted into said cylinder.

6 more elements

Dependencies are inferred from the claim text.

Rod accumulator riser tensioning cylinder assembly

Life of this patent

Rod accumulator riser tensioning cylinder assembly

Life of this patent

Abstract

Claims17