RU2806890C1 - Heat-resistant column wedded trim and sealing unit for it - Google Patents

Abstract

FIELD: thermally resistant wedge column piping.

SUBSTANCE: heat-resistant column wedge piping includes a body and a cover. A wedge suspension coupled with the inner conical surface of the body is also included. A ground follower bolted to the end of the cover is also included. An annular metal seal is placed between the ends of the body and the cover. The piping also includes injection and discharge valves screwed into the through holes of the body and cover. A top seal installed between the production string pipe and the cap is also included. Anti-extrusion profiled metal rings are placed along the ends of the upper seal on the pipe side of the production string. The outer annular protrusion of the ground follower is installed on the upper seal. The sealing unit, located above the wedge suspension, contains internal and external sealing elements. The internal sealing element is in contact with the production string pipe. Anti-extrusion profiled metal rings are placed along the ends of the internal sealing element on the side of the production string pipe, preventing it from being squeezed out into the gap from the sealing unit under the action of pressure from the well environment. The external sealing element is in contact with the piping body of the column heat-resistant wedge. The support ring is equipped with a central protruding flange and two conical seating surfaces on which the inner and outer sealing elements are installed. Two pressure rings are located coaxially, each equipped with dependent projections, symmetrical with respect to the central protruding flange on the support ring, are engaged and independently fixed by means of fastening. In addition, the compressive force on the inner and outer sealing elements of each individual pressure ring is adjusted independently of each other by the locking means.

EFFECT: increased heat resistance, prevention of formation of gaps between the sealing element and the pipe of the production string, regardless of the design size of the latter, and the ability to eliminate loss of tightness.

1 cl, 3 dwg

Description

The group of inventions relates to the oil production industry, in particular, for piping the mouth of steam injection wells and is used for suspending casing strings, isolating annular spaces, controlling the pressure in them, sealing the tubular and annulus spaces of wells.

A heat-resistant column head is known, containing two detachable housings: upper and lower. The lower body is equipped with rings, elastic cuffs, and chest straps. The connection elements are made in the form of fasteners, which serve to seal the sealed element - the production string - with elastic cuffs. The production column is connected to the upper casing. (Patent RU 2234587 C1 for the invention “COLUMN HEAT-RESISTANT HEAD.” – IPC: E21B 33/04 - 08/20/2004).

The disadvantages of the known heat-resistant column head are: the absence of retaining wedges, the presence of only one sealing unit, which seals only the production string and is pressed only by the upper flange, insufficient reliability of sealing the wellhead.

Analysis of technical solutions showed that a column head is known, which is the closest technical solution for tying a column with a heat-resistant wedge in accordance with the invention. The column head contains a housing and a cover with pipes. On the outer cylindrical surface of the coupling inside the housing there is a cuff with a movable sleeve. The lower cuff is located in the cavity between the coupling and the body. The outer annular protrusion of the cover is installed on it. An upper cuff is located in the cavity between the coupling and the inner conical surface of the cover. The outer annular protrusion of the ground axle is installed on it. The ground box is bolted to the end of the cover. An annular metal seal is placed between the ends of the body and the cover. Studs with nuts are inserted into the holes of the body and cover flanges evenly spaced around the circumference. Inside the coupling there is a wedge suspension with an axial channel and holes. The conical surface of the wedge suspension is connected to the inner surface of the coupling. With teeth located in the axial channel, the wedge suspension holds the production string by its coupling. A blowout ring is installed above the wedge hanger at the top of the coupling, and a column flange is screwed into this coupling. (Patent RU 2146000 C1 for the invention “COLUMN HEAD”. – IPC E21B 33/04 - 02/27/2000).

The disadvantage of the closest analogue is the lack of heat resistance. Also, when installing piping on old casing pipes that have deformations, it will not be possible to ensure a tight connection.

A head for landing a casing string is known, containing a cylindrical body with two flanges, a landing seat with an internal conical landing surface, a wedge suspension and a sealing unit. The seat is made with longitudinal bypass slots for supplying gas or oil to the outlet pipes in the side wall of the housing. The support ring is equipped with a central protruding flange. The sealing unit consists of two rings placed on a support ring. The inner ring of the sealing assembly is in contact with the production string pipe. The outer ring of the sealing assembly is in contact with the housing. The support sleeve is installed above the sealing unit. Set screws are screwed into the support sleeve and can be moved downwards in order to simultaneously adjust the sealing unit, thereby further sealing it. (Patent US 2471658 for the invention “Casing landing head”. IPC E21B33/04 – 05/31/1949).

The disadvantage of the known head for landing casing is the lack of heat resistance, the impossibility of separately pressing the sealing elements to the body and to the production string pipe, which leads to a direct dependence on the operational size of the production string pipe and loss of tightness of the wellhead due to the formation of gaps between the sealing element and the production string pipe .

Analysis of technical solutions showed that a casing head is known, which is the closest technical solution to a sealing unit in accordance with the invention. The casing head contains a lower single-flange body and an upper double-flange body. Pipe adapter installed on the upper double flange body. Wedge suspension installed in the lower housing. Between each pair of flanges there is an annular deformable sealing ring element. The upper seal assembly is located in the upper housing. The lower seal assembly includes an inner and outer O-ring mounted on a back-up ring. The support ring is located above the wedge suspension and is pressed by a pressure ring. The support ring is equipped with a central protruding flange and two conical seating surfaces on the sides. The pressure ring is equipped with two dependent projections located symmetrically relative to the central protruding flange on the support ring. The inner O-ring of the lower seal is in contact with the production string pipe. The outer ring of the lower seal is in contact with the housing. Locking screws and nuts are screwed into evenly spaced holes in the flanges of the upper and lower housings and rest against the conical surfaces of the sealing and pressure rings. The locking screws are used to compress the upper seal assembly to adjust the tightness of the lower seal assembly. (Patent US 2617485 for the invention “Casing head”. IPC E21B33/04 – 11/11/1952).

The disadvantage of the closest analogue is the simultaneous compression of the sealing elements to the housing and to the production string pipe during operation of the production string head, which leads to a direct dependence on the operational size of the production string pipe and loss of wellhead tightness due to the formation of gaps between the sealing element and the production string pipe.

The objective of the group of inventions is to increase the reliability of sealing the pipe and annulus of wells.

The technical result achieved in the process of solving this problem is as follows:

- eliminating the formation of gaps between the sealing element and the pipe of the production string, regardless of the design size of the latter;

- the ability to eliminate loss of tightness;

- the ability to operate the sealing unit under high pressure conditions.

The technical result is achieved by the fact that the heat-resistant column wedge piping contains a cylindrical body with an internal conical surface, a cover, a wedge suspension, a ground axle with an axial channel installed at the upper end of the cover, a column flange, and additionally contains injection and discharge valves screwed into through holes in the flanges housing and cover, an upper seal on which the outer annular protrusion of the ground bushing is installed, located between the production string pipe and the cover, anti-extrusion profiled metal rings at the ends of the upper seal on the side of the production string pipe, a sealing unit located above the wedge suspension.

The heat-resistant column wedge piping sealing unit, located above the wedge suspension, is made of heat-resistant material and contains internal and external sealing elements. The internal sealing element is in contact with the production string pipe. Anti-extrusion profiled metal rings are placed along the ends of the internal sealing element on the side of the production string pipe, preventing it from being squeezed out into the gap from the sealing unit under the action of pressure from the well environment. The external sealing element ensures sealing of the piping body with a heat-resistant column wedge. The support ring is equipped with a central protruding flange and two conical seating surfaces on which the inner and outer sealing elements are installed. Two pressure rings are located coaxially and are each equipped with dependent projections, symmetrical with respect to the central protruding flange on the support ring. The compressive force on the inner and outer sealing elements of each individual pressure ring is adjusted independently of each other by means of fastening means.

The combination of these features ensures the achievement of a technical result.

Based on the above and the patent research conducted, we can conclude that we have not identified technical solutions that are based on features that coincide with all the distinctive features of the proposed technical solution.

It follows from this that the technical solution does not clearly follow from the prior art, from which we can conclude that the group of inventions meets the “inventive step” criterion.

The technical essence, design and principle of operation of the heat-resistant wedge column piping and sealing unit are explained in the following drawings:

Figure 1 – column wedge heat-resistant piping.

Figure 2 – sealing unit.

Figure 3 – relative position of pressure rings and fastening means.

The heat-resistant column wedge piping consists of a body 1, a cover 2, an adapter flange 3, a wedge suspension 4, a blind flange 12. An annular metal seal 5 is installed between the flanges of the body 1 and the cover 2, which are tightened with studs with nuts 8,9, and ensures sealing of this connections.

The upper seal 11 is installed between the cover 2 and the pipe of the production string and is pressed by the outer annular protrusion of the ground follower 6, fixed with studs and nuts 13, 14. Anti-extrusion profiled metal rings 24 are laid along the ends of the upper seal. The sealing unit 7 is installed above the wedge suspension 4. In the through holes Injection and unloading valves 22, 23 are installed on the flanges of housing 1 and cover 2.

Heat-resistant column wedge piping works as follows:

The heat-resistant column wedge piping is mounted at the wellhead.

On the side outlets of the housing 1, devices for monitoring and relieving pressure or shut-off valves are installed through ring metal seals 10.

Structurally, the wedge suspension 4 is designed so that it can freely pass through the annular section between the casing and the blowout prevention equipment. When moving the casing, the wedge suspension 4 automatically tightly covers and cuts into it with its teeth. For the purpose of cementing, the column can be unloaded onto a wedge suspension 4. In this case, circulation is carried out through the side branches of the heat-resistant column piping.

The sealing unit includes a support ring 16, an internal sealing element 17 and an external sealing element 18, fastening means 19, pressure rings 20, 21. Anti-extrusion profiled metal rings 25 are placed at the ends of the internal sealing element.

The sealing unit works as follows:

Due to the deformation of the internal sealing element 17 and the external sealing element 18 in the process of pre-compression when installing the casing in the well, the seal is carried out from the side of the production casing and the casing of the casing 1. Anti-extrusion profiled metal rings 25 prevent the internal sealing element from being squeezed into the gap from the sealing unit during action pressure of the well environment.

The conical edges help to press against the sealed surfaces, providing a self-sealing effect.

Due to the independent adjustment of the compressive forces of the pressure rings 20, 21 by means of fastening means 19, the sealing elements are pressed with different forces during operation. It becomes possible to seal the wellhead regardless of the design size of the production string pipe.

Claims (1)

Column wedge heat-resistant piping, including a cylindrical body with an internal conical surface, a cover, a wedge suspension, a core with an axial channel installed on the upper end of the cover, a column flange, ring metal seals, anti-extrusion profiled metal rings at the ends of the upper seal on the pipe side of the production string, an upper seal located between the production string pipe and the cover, on which the outer annular protrusion of the ground axle is installed, characterized in that it contains injection and unloading valves screwed into through holes in the flanges of the housing and cover, a sealing unit for piping the column with a heat-resistant wedge, located above the wedge suspension , including internal and external sealing elements installed on the support ring, while the internal sealing element is in contact with the production string pipe, and the outer sealing element is in contact with the casing piping body of the column with a heat-resistant wedge, a support ring equipped with a central protruding flange and two landing conical surfaces, the sealing elements are made of heat-resistant material and are installed with the possibility of separately adjusting the compressive forces by means of fastening means, contains anti-extrusion profiled metal rings laid along the ends of the internal sealing element on the side of the production string pipe, preventing it from being squeezed into the gap from the sealing unit under pressure well environment, two pressure rings located coaxially, each equipped with dependent projections, symmetrical with respect to the central protruding flange on the support ring, engaged and independently fixed by means of fastening.