SU1724895A1 - Twinned marine riser tensioner for floating drilling vessels - Google Patents

Abstract

The invention relates to offshore drilling for oil and gas from floating drilling rigs and can be applied in dual seawater tensions. The aim of the invention is to improve the reliability and performance properties. The dual tensioner contains the upper 12 and lower 13 supports, pneumatic-hydraulic cylinders 1, on the rods of which there are fixed moving blocks 4, hydro-pneumatic accumulators 8 high pressure, a guide

Description

rack 11, means of fixing each stock from the reversal. The guide post 11 is provided with a ring-shaped stop 14 located in its upper part, made with, - grooves and secured in supports.

Each stem locking means includes a rod 9 with a finger fixed on the corresponding movable rod to interact with the groove of the guide post. 3 il.

The invention relates to offshore drilling for oil and gas from floating drilling rigs and can be applied in dual seawater tensions.

A device for tensioning a seaway of a floating drilling rig is known, which contains a pneumatic-hydraulic cylinder with a piston, the rod of which is equipped with a block of ropes of nat residents, a low-pressure hydraulic accumulator that communicates hydraulically with the super-piston cavity of the pneumatic-hydraulic cylinder, and a high-pressure pneumo-accumulator connected to a piston cavity. pneumohydraulic cylinder, and piston seal assembly.

The known device for nat inhabitants of the seaway is used for single nat residents, the disadvantage of which is the large size and weight, which, when placed on a floating drilling rig, requires considerable areas and organization of metal-intensive supporting structures at the nat installation sites.

To eliminate these drawbacks, dual tensioners are used with closely spaced moving blocks of sliding parts and a single support of fixed blocks, thus reducing the total weight of the tension system and the areas occupied by this system on the floating drilling rig. Moreover, in order to avoid collision and damage of the movable blocks during operation or break of the rope, when the sliding parts are deployed around the longitudinal axis, devices are used that hold the sliding parts from turning over the entire stroke length.

A dual tensioner is known that contains pneumatic-hydraulic cylinders with pistons, the rods of which are equipped with movable blocks, high-pressure hydropneumatic accumulators, communicated with the piston cavities of pneumohydraulic cylinders, a guide strut fixed in the upper part of the cylinders, the longitudinal grooves of which interact with fingers of mobile blocks, holding sliding parts from a turn.

A disadvantage of the known double tensioner is the presence of a cantilever guide post, protruding beyond the dimensions of the body, for an amount of stroke, which makes it difficult for the tensioner to be mounted on the drilling rig, it does not exclude its breakage, and winding the rope on the guide post in case its breakage, increases the time to replace the rope on the rig.

The purpose of the invention is to improve the reliability and performance properties.

This goal is achieved by the fact that a dual tensioner, containing upper and lower supports, pneumatic-hydraulic cylinders, on the rods of which movable blocks are fixed, high-pressure accumulators and a guide post, is equipped with means for fixing each rod against a turn, the guide post is equipped with the top of the ring-shaped stop,

grooved and secured in bearings, with each stem locking means incorporating a rod with a finger rigidly mounted on a corresponding movable rod to interact with the groove of the guide post.

The use of the proposed technical solution makes it possible to place the guide post inside the tensioner, exclude its protruding over the dimensions and possible damage during installation and operation, and also exclude the winding of the rope when it breaks, which together increases the reliability and operational properties.

FIG. 1 shows the dual tensioner, general view; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a section BB in FIG. one.

The dual tensioner contains two pneumatic-hydraulic cylinders 1 (Fig. 1),

inside which are installed pistons 2 with rods 3, at the ends of which are fixed moving blocks 4, the rod cavity 5 of each cylinder 1 is hydraulically communicated with a low-pressure hydropneumatic accumulator 6

Piston cavity 7 of each cylinder 1 is hydraulically communicated with high-pressure hydro-pneumatic accumulators 8. On the rod 3 is rigidly fixed rod 9 with fingers 10 (Fig. 3).

The fingers 10 interact with the slots of the guide post 11, the upper and lower ends of which are attached to the supports 12 and 13 (Fig. 1). On the rack 11 (Fig. 3) in its upper part there is an annular stopper 14 (Fig. 2).

Dual tensioner works as follows.

When the floating drilling rig oscillates up and down, the change in the length of the tension cable (not shown) is compensated for by the movement of the rods 3 in the cylinders 1 under the pressure of compressed air and hydraulic fluid supplied to the cavity 7.

Together with the movable blocks 4, the rods 9 move, the fingers of which interact with the grooves of the guide post 11, thereby keeping the rods 3 from turning.

In order to prevent the fingers .10 of the rods 9 from exiting the grooves of the guide post 11, an annular stop 14 is provided in the upper part of the tension, encompassing the rods 9 with a clearance. Moreover, with an increase in the stroke of the rods 3, the fingers 10 of the rod 9 approach the ring-shaped limit - 4

to reader 14, contributing additionally to keeping them engaged.

Placing the guide post and its rigid fastening inside the tensioner eliminates the swinging and breakage of the rack, winding the rope on it when the breakage is reduced, reduce the time for replacing the rope, improve the reliability and performance properties in general.

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Formula

The dual tensioner of the seaway of floating drilling rigs, containing upper and lower supports, pneumohydraulic 5 cylinders, on the rods of which there are fixed moving blocks, high pressure hydropneumatic accumulators and a guide post, characterized in that, in order to increase reliability and

0 operational properties, it is provided with a means for fixing each stem against a reversal, the guide post is provided with a ring-shaped stop located in its upper part, is made with grooves and is fixed in supports, with each means for fixing the rods including a rod rigidly fixed on the corresponding movable rod with finger for engaging the slot of the guide post.

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Claims (1)

Claim A double tensioner for the riser of floating drilling rigs, containing upper and lower supports, pneumatic-hydraulic cylinders, on the rods of which are movable blocks, high-pressure hydraulic accumulators and a guide rack, characterized in that, in order to increase reliability and operational properties, it is equipped with a means for fixing each rod from a turn, the guide rack is equipped with an annular limiter located in its upper part, made with grooves 25 and fixed in supports, each means in fixing the rods includes a rod with a finger rigidly fixed to the corresponding movable rod to interact with the groove of the guide rack. B - 5 '