RU2719798C1 - Annular seal with metal-to-metal seal - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention relates to annular seal with metal-to-metal seal. Annular seal with metal-to-metal seal includes metal-to-metal seal, upper armature body, upper body, shear pins top, upper shear bolts, bottom anchor, lower body, shear pins lower, shear bolts bottom. Upper armature body is made in the form of a cylinder and has in its upper part a profile for fixation of tools for installation and extraction of the annular seal. In lower part of upper armature housing there are hooks. Hooks have a profile with an angle for engagement with collets collet lugs of upper and compression of collet lobes. Lower part of the upper armature casing along the circle line includes holes for installation of shear pins. Armature upper body is arranged in upper body and fixed relative to it by means of shear pins. Upper case has a wedge element in its lower part to activate the seal, and in the upper part there are collet lobes. Collet lugs of the upper casing contain lengthwise grooves for installation and movement in them of hooks of the casing of the upper casing, and holes for installation of pins of shear and fixation relative to the casing of the upper casing. Wedge element includes holes for installation of shear and locking screws relative to seal. Facets of longitudinal slots-guides of the upper body located in the upper part of the body can be made in the form of a chamfer with an angle equal to an angle on hooks of the upper armature casing, which serve for hooks of the upper casing and compression of collet lobes. Seal has annular profiles and on both sides of seal has holes for installation of shear and locking screws relative to housing upper and housing lower. Lower anchor has in its upper part collet lobes, which include longitudinal slots serving as guides for installation and movement in them of hooks of lower case and holes for installation of shear pins. Faces of the lower anchor longitudinal grooves are made in the form of a chamfer with an angle equal to the angle on the hooks of the lower case. Lower case has wedge for activation of seal and hooks. Wedge element comprises holes for installation of shear bolts. Casing of the column head of the conductor column has on its inner surface a sealing surface, as well as a toothed profile providing the annular seal fixation. Sealing housing of the casing string has a sealing surface on the outer surface, as well as a toothed profile providing annular seal fixation.EFFECT: technical result is higher reliability of sealing.3 cl, 13 dwg

Description

FIELD OF THE INVENTION

The invention relates to a device used in the operation of offshore and surface wells, namely, the design of annular seals with metal-to-metal seals intended for sealing the annular space between the casing suspension housing and the conductor casing head housing. The proposed seal can be widely used in the construction of both offshore and onshore wells in the oil, chemical, energy and other industries.

BACKGROUND

Various types of seals are used to seal the annular space between the casing suspension housing and the casing of the casing string head, designed to prevent or reduce leakage of liquid or gas through the gaps between the parts. Typically, metal-to-metal seals are used for these purposes.

In the text of the present description, by activating the seal, one should understand the process of transition of the seal from its initial position to the working position, in which sealing of the annular space between the casing suspension housing and the conductor casing column head housing is achieved.

Deactivation of a seal should be understood as the process of moving a seal from its working position to its original position.

Known annular metal-to-metal sealing (US2010327532 (A1); IPC ЕВВ 33/02; F16L 21/04; published December 30, 2010) used for sealing between two tubular elements. The seal may have an inner and outer seal ring or more than one pair of inner and outer seal rings activated by wedge devices that can be mounted in place with a running tool. The annular ring may have a conical or convex surface and may create a preload force on the o-rings.

The disadvantage of the technical solution is that the design of the annular seal lacks elements that prevent displacement during axial actions of wedge devices, which can lead to a decrease in the force exerted on the sealing rings and, as a result, to a partial or complete loss of tightness. Another disadvantage is that the sealing rings have teeth to prevent axial displacements, which, when activated, leave traces on the sealing surfaces of the conductor casing and the casing suspension housing, which makes it impossible to reinstall the annular seal in case of unsuccessful activation of the annular seal.

The closest technical solution, chosen as a prototype, is a metal-to-metal annular seal (US 2009322030; IPC Е21В 33/10; published: 12/31/2009; IPC: Е21В 33/10), designed to seal a subsea wellhead assembly, including metal O-ring made in the form of a cylinder and activated by a wedge device. The sealing surface of the casing string casing and the casing suspension are made in the form of teeth. The sealing ring, pressing into the teeth of the sealing surfaces, seals the annular space and at the same time fixes the annular seal against axial movements.

The disadvantage of the technical solution is that the sealing ring is both a sealant and a retainer from axial movements and during interaction (indentation) with the gear profile, as a result of which there is a high risk of damage to the sealing surface of the sealing ring.

SUMMARY OF THE INVENTION

The technical result is to increase the reliability of sealing the annular seal during operation due to the double-sided seal containing one sealing barrier on each side and activated by two wedges, and the mechanism of bilateral fixation of the seal located on both sides of the double-sided seal, ensuring no axial play after installation. The proposed design provides the necessary radial deformation of the metal-to-metal sealing element in the annulus with a predetermined force to ensure sealing by two circuits.

The seal can be deactivated at any stage of the installation, while the deactivation force is much less than the activation force.

The technical result is achieved by means of an annular seal with a metal-to-metal seal designed to seal the annular space between the casing suspension housing and the conductor casing head housing containing a metal-to-metal seal, which according to the invention includes an upper armature housing, an upper arm, shear pins upper, upper shear screws, lower anchor, lower body, lower shear pins, lower shear screws.

The upper anchor body, made in the form of a cylinder, has a profile in the upper part for fixing tools for installing and removing the annular seal; in the lower part of the upper anchor housing there are hooks located along a circle line with the outer and inner surfaces of the upper anchor housing, having a profile with an angle for engagement with collet petals of the upper housing and compression of the collet petals.

The lower part of the upper armature along the circle includes holes for installing shear pins.

The upper anchor housing is located in the upper housing and is fixed relative to it with shear pins.

The upper body, made in the form of a cylinder, has a wedge element in the lower part for activating the seal, and collet petals in the upper part, which are configured to be activated by the upper armature for fixing the conductor column head and casing suspension in the toothed profile of the casing.

Moreover, the collet petals of the upper case contain longitudinal grooves serving as guides for installing and moving the hooks of the upper anchor body in them, as well as holes designed to install the upper shear pins and fixation relative to the upper anchor body, the wedge element includes holes for installing the upper shear and fixation screws regarding compaction.

The faces of the longitudinal grooves-guides of the upper case, located in the upper part of the case, are made in the form of a chamfer with an angle equal to the angle on the hooks of the upper armature body, and serve to hook the upper body with hooks and compress the collet tabs.

The seal is made in the form of a cylinder having, on the outer and inner surfaces, symmetrically with respect to the center of the seal, annular profiles made with the possibility of pressing the conductor column head housing and the casing string suspension housing into the sealing surfaces when the annular seal is activated; on both sides of the seal contain holes for installing shear screws and fixation relative to the upper housing and the lower housing.

The seal is made with the possibility of activation from below using a wedge element of the lower case and from above using a wedge element of the upper case.

The lower anchor, made in the form of a cylinder, having collet petals in the upper part, is configured to be activated by the lower casing for fixing in the toothed profile of the casing column head body and toothed casing suspension housing profile.

Collet petals of the lower anchor include longitudinal grooves, which serve as guides for installing and moving the hooks of the lower case and the holes for installing the shear lower pins and fixing relative to the lower case.

The faces of the longitudinal grooves-guides of the lower anchor, located in the upper part of the lower anchor, are made in the form of a chamfer with an angle equal to the angle on the hooks of the lower case, which serve to hook the lower case with hooks and compress the collet tabs.

The lower case, made in the form of a cylinder, having in the upper part a wedge element for activating the seal; in the lower part of the lower case there are hooks located in a circle line with the outer and inner surfaces of the lower case; having a profile with an angle for engagement with the collet petals of the lower anchor and compression of the collet petals.

Moreover, the wedge element contains holes for installing the lower shear screws and fixing relative to the seal.

The lower part of the lower circumferential housing includes holes for installing shear pins and fixing relative to the lower anchor.

The shear pins and shear screws are configured to provide phased activation of the annular seal.

The conductor column head housing of the conductor made in the form of a cylinder having a sealing surface on the inner surface for sealing the annular space between the casing suspension housing and the conductor column head housing, as well as a toothed profile for fixing the annular seal.

The casing suspension housing, made in the form of a cylinder, having a sealing surface on the outer surface for sealing the annular space between the casing suspension housing and the conductor casing string head housing, as well as a toothed profile that secures the annular seal.

Hooks located along the circle line from the outer and inner surfaces of the upper anchor body can have a profile with an angle of 40-50 ° for engagement with the collet petals of the upper body and compress the collet petals.

The hooks located along the circle line with the outer and inner surfaces of the lower body can have a profile with an angle of 40-50 ° for engaging the lower armature with collet petals and compressing the collet petals.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated by drawings, where:

in FIG. 1 shows a general view of an annular metal-to-metal seal in position before activation (section);

in FIG. 2 shows the upper armature body (section);

in FIG. 3 presents the upper case (section);

in FIG. 4 shows an annular metal-to-metal seal (section);

in FIG. 5 shows the lower anchor (section);

in FIG. 6 shows the lower case (section);

in FIG. 7 shows a casing of a column head of a conductor column;

in FIG. 8 shows the inner surface of the casing of the column head of the conductor column (section);

in FIG. 9 shows a casing suspension housing;

in FIG. 10 shows a first step of activating an annular seal;

in FIG. 11 shows a second step for activating an annular seal;

in FIG. 12 shows a third step of activating an annular seal;

in FIG. 13 shows a step for deactivating an annular seal.

The following notation is made in the drawings:

1 - upper anchor body;

2 - profile for fixing tools;

3 - hooks located in a circle line;

4 - holes for installing the shear top pins;

5 - upper shear pins;

6 - upper case;

7 - wedge element to activate the seal;

8 - collet petals of the upper body;

9 - longitudinal grooves - guides for installing and moving the hooks of the upper armature body in them;

10 - holes on the collet petals for installing shear pins;

11 - holes on the wedge element;

12 - upper shear screw;

13 - seal;

14 - ring seal profiles;

15 - holes for installing shear screws;

16 - lower anchor;

17 - collet petals;

18 - longitudinal grooves - guides for installing and moving the hooks of the lower case into them;

19 - holes on the collet petals for installing shear pins;

20 - lower shear pins;

21 - lower case;

22 - wedge element;

23 - hooks located in a circle line;

24 - holes on the wedge element for installing shear screws;

25 - openings of the lower case for installing shear pins;

26 - lower shear screw;

27 - casing of the column head of the conductor column;

28 - the sealing surface of the casing of the column head of the column of the conductor;

29 is a gear profile of the body of the column head of the conductor column;

30 - casing suspension housing;

31 - sealing surface of the casing suspension housing;

32 - toothed profile casing suspension housing;

33 - collet petals of the lower anchor 17 are pressed into the toothed profiles of the casing head housing and the casing suspension housing;

34 - shear lower pins are destroyed;

35 - the lower case is displaced inside the lower anchor;

36 - places of contact pressure of the seal 13;

37 - wedge elements of the lower case 22 and the upper case 6 are pressed into the seal 13;

38 - upper and lower shear screws are destroyed;

39 - upper shear pins are destroyed;

40 - collet petals of the upper casing are pressed into the gear profiles of the casing of the casing head and the casing of the suspension;

41 - the upper armature body is shifted into the upper body;

42 - engagement of the hooks of the upper armature housing for the counterpart of the upper housing;

43 - the upper armature housing is displaced upward relative to the upper armature.

DETAILED DESCRIPTION OF THE INVENTION

An annular seal with a metal-to-metal seal designed to seal the annular space between the casing suspension housing 30 and the conductor casing string head housing 27, comprising a metal-to-metal seal 13, including:

case 1 upper anchor, upper case 6, upper shear pins 5, upper shear screws 12,

lower anchor 16, lower case 21, lower shear pins 20, lower shear screws 26.

The upper armature body 1, made in the form of a cylinder, having a profile 2 in the upper part for fixing tools for installing and removing the annular seal; in the lower part of the housing 1 of the upper anchor contains hooks 3 located along a circle line from the outer and inner surfaces of the housing 1 of the upper anchor, having a profile with an angle for engagement with the collet petals 8 of the upper housing and compression of the collet petals.

And also the lower part of the body 1 of the upper anchor in a circle line includes holes 4 for installing the shear pins of the upper 5.

The upper armature body 1 is placed in the upper body 6 and is fixed relative to it using shear pins 5.

The upper case 6, made in the form of a cylinder, having a wedge element 7 in the lower part for activating the seal 13, and collet lobes 8 in the upper part, which are configured to be activated by the upper armature body 1 for fixing in the gear profile 29 of the column head body of the conductor column and the body 30 casing hangers.

Moreover, the collet petals 8 of the upper case contain longitudinal grooves 9, which serve as guides for installing and moving the hooks 3 of the upper anchor body in them, as well as the holes 10, designed to install the upper shear pins 5 and fix relative to the body 1 of the upper anchor, the wedge element 7 includes holes 11 for installing the upper shear screws 12 and fixing relative to the seal 13.

The faces of the longitudinal grooves-guides 18 of the upper housing located in the upper part of the housing are made in the form of a chamfer with an angle equal to the angle on the hooks of the housing 1 of the upper armature, which are used for engagement with hooks 3 of the upper housing and compression of the collet petals 8.

The seal 13 is made in the form of a cylinder having, on the external and internal surfaces, symmetrically with respect to the center of the seal, annular profiles 14 made with the possibility of pressing the sealing surfaces 28 of the casing column head housing and the sealing surfaces 31 of the casing suspension housing upon activation of the annular seal; on both sides of the seal 13 contains holes 15 for installing the upper shear screws 12 and fixing relative to the upper housing 6 and the lower housing 21.

The seal 13 is configured to be activated from below using a wedge element 22 of the lower case and from above using a wedge element 7 of the upper case.

The lower anchor 16 is made in the form of a cylinder, having collet petals 17 in the upper part, configured to be activated by the lower housing 21 for fixing in the toothed profile 29 of the casing string head body and the cogged profile of the casing suspension housing 32.

Collet petals 17 of the lower anchor include longitudinal grooves 18, which serve as guides for installing and moving the hooks 23 of the lower case and the holes 19 for installing the shear pins of the lower 20 and fixing relative to the lower case 21.

The faces of the longitudinal grooves-guides 18 of the lower anchor located in the upper part of the lower anchor 16 are made in the form of a chamfer with an angle equal to the angle on the hooks 23 of the lower case, which are used to engage the hooks 23 of the lower case and compress the collet tabs 17.

The lower housing 21, made in the form of a cylinder, having in the upper part a wedge element 22 for activating the seal; in the lower part of the lower case contains hooks 23 located along a circle line from the outer and inner surfaces of the lower case 21; having a profile with an angle for engagement with collet petals 17 lower anchors and compression collet petals 17.

Moreover, the wedge element 22 contains holes 24 for installing the shear screws lower 26 and fixing relative to the seal 13.

The lower part of the body 21 of the lower circumferential line includes holes 25 for installing the shear pins of the lower 26 and fixing relative to the anchor of the lower 16.

Shear pins (5 and 20) and shear screws (12 and 26) are configured to provide phased activation of the annular seal.

The housing 27 of the column head of the conductor column, made in the form of a cylinder having a sealing surface 28 on the inner surface for sealing the annular space between the casing suspension housing 30 and the housing of the column head of the casing string column 27, as well as a toothed profile 29, which fixes the annular seal.

The casing suspension housing 30, made in the form of a cylinder, having a sealing surface 31 on the outer surface for sealing the annular space between the casing suspension housing 27 and the conductor casing string head housing 30, as well as a toothed profile 32 for fixing the annular seal.

Hooks 3 located along a circle line from the outer and inner surfaces of the upper armature housing 1 may have a profile with an angle of 40-50 ° for engaging with collet petals 8 of the upper housing and compressing the collet petals 8.

The hooks 23 located along the circle line with the outer and inner surfaces of the lower housing 21 may have a profile with an angle of 40-50 ° for engaging with the collet petals 17 of the lower anchor and compressing the collet petals 17.

The device operates as follows.

The first stage of activation of the annular seal is fixing the lower anchor 1.

Under the influence of the force from the tool for installing the annular seal on the upper armature body 1, the shear pins of the upper 20 are destroyed between the lower armature 16 and the lower armature 21, as a result of which the lower arm 21 is displaced inside the lower armature 16, pressing the collet tabs 17 into the gear profiles of the housing 27 casing head and casing suspension housing 30 (see FIG. 10).

The second stage of annular seal activation is sealing.

With further action of the force from the installation tool, the shear screws 12 and 26 are destroyed and the wedge elements 22 are pressed in and the lower body 21 and the upper body 6 are pressed inside the seal 13;

as a result, the seal 13 is deformed between the annular profiles 14 of the seal, the casing string head housing 27 and the casing string suspension housing 30, contact pressure arises, thus sealing the annular seal (see Fig. 11).

The third stage of activation of the seal is fixing the anchor of the upper 1.

Further, under the influence of force from the installation tool, the shear pins of the upper 5 are destroyed, between the upper case 6 and the upper armature body 1;

as a result, the upper armature body 1 is shifted into the upper body 6, pressing the collet tabs 8 of the upper body into the gear profiles 29 of the casing head housing and the casing suspension housing 30, which, together with the work of the lower armature 16, excludes the possibility of moving the annular seal in the axial direction under exposure to buoyancy forces. Thus, the final activation of the annular seal occurs (see FIG. 12).

Deactivation of the annular seal.

If it is necessary to deactivate the annular seal, the upper armature body 1 is moved upward by applying force in the corresponding direction with the tool to extract the annular seal. In this case, the hooks 3 of the upper armature body engage with the counterpart in the longitudinal grooves-guides 9 of the upper body (see Fig. 13). The design of the hooks 3 having a reciprocal angle provides compression of the collet lobes 8 of the upper housing and its release from gearing with the housing 27 of the column head of the conductor string and the housing 30 of the casing string. Further application of the deactivation force will lead to the release of the seal 13, and then the lower armature 16, similarly to the release of the body 1 of the upper armature.

Thus, the proposed annular seal with metal-to-metal sealing allows to increase the reliability of sealing the annular seal during operation due to the two-sided sealing, containing one sealing barrier on each side and activated by two wedges and a two-way locking mechanism of the seal, ensuring the absence of axial play after installation. The proposed design provides the necessary radial deformation of the metal-to-metal sealing element in the annulus with a predetermined force to ensure sealing by two circuits.

Modifications and improvements to the above described embodiments are readily apparent to those skilled in the art. The above description is provided solely as an example, and is not limiting.

Claims (20)

1. An annular seal with a metal-to-metal seal, designed to seal the annular space between the casing suspension housing and the conductor casing head housing, comprising a metal-to-metal seal, characterized in that it includes an upper armature housing, an upper housing, upper shear pins , upper shear screws, lower anchor, lower case, lower shear pins, lower shear screws, the upper armature body, made in the form of a cylinder, having in the upper part a profile for fixing tools for installing and removing the annular seal; in the lower part of the upper anchor housing there are hooks located on a circle line with the outer and inner surfaces of the upper anchor housing, having a profile with an angle for engagement with the collet petals of the upper housing and compression of the collet petals, the lower part of the upper armature along the circle includes holes for the installation of shear pins, the upper anchor housing is located in the upper housing and is fixed relative to it using shear pins, the upper case, made in the form of a cylinder, having a wedge element in the lower part for activating the seal, and collet petals in the upper part, which are configured to be activated by the upper armature for fixing in the toothed profile of the casing column head body and casing suspension, moreover, the collet petals of the upper case contain longitudinal grooves that serve as guides for installing and moving the hooks of the upper anchor body in them, as well as the holes for installing the shear pins and fixing relative to the upper armature body, the wedge element includes holes for installing the shear screws and fixing relative to the seal , the edges of the longitudinal grooves-guides of the upper case located in the upper part of the body can be made in the form of a chamfer with an angle equal to the angle on the hooks of the upper armature housing, which are used to engage the upper body hooks and compress the collet tabs, the seal is made in the form of a cylinder having, on the outer and inner surfaces, symmetrically with respect to the center of the seal, annular profiles configured to press the conductor column head housing and the casing suspension housing into the sealing surfaces when the annular seal is activated; on both sides of the seal contain holes for installing shear screws and fixation relative to the upper housing and the lower housing, the seal is made with the possibility of activation from below using a wedge element of the lower case and from above using a wedge element of the upper case, lower anchor, made in the form of a cylinder, having collet petals in the upper part, configured to be activated by the lower housing for fixing in the toothed profile of the casing column head housing and the casing suspension, collet petals of the lower anchor include longitudinal grooves serving as guides for installing and moving the hooks of the lower case and the holes for installing shear pins and fixing relative to the lower case, the faces of the longitudinal grooves-guides of the lower anchor, located in the upper part of the lower anchor, are made in the form of a chamfer with an angle equal to the angle on the hooks of the lower case, which serve to hook the lower case with hooks and compress the collet tabs, a lower case made in the form of a cylinder having a wedge element in the upper part for activating the seal; in the lower part of the lower case there are hooks located in a circle line with the outer and inner surfaces of the lower case; having a profile with an angle for engagement with the collet petals of the lower anchor and compression of the collet petals, moreover, the wedge element contains holes for installing shear screws and fixing relative to the seal, the lower part of the lower circumferential housing includes holes for installing shear pins and fixing relative to the lower anchor, shear pins and shear screws are configured to provide phased activation of the annular seal, a conductor column head housing of the conductor made in the form of a cylinder having a sealing surface on the inner surface for sealing the annular space between the casing suspension housing and the conductor column head housing, as well as a toothed profile for fixing the annular seal, casing suspension housing made in the form of a cylinder having a sealing surface on the outer surface for sealing the annular space between the casing suspension housing and the conductor casing column head housing, as well as a toothed profile for fixing the annular seal. 2. An annular seal according to claim 1, characterized in that the hooks located along a circle line from the outer and inner surfaces of the upper anchor body have a profile with an angle of 40-50 ° for engagement with the collet petals of the upper body and compress the collet petals. 3. An annular seal according to claim 1, characterized in that the hooks located along a circle line from the outer and inner surfaces of the lower body can have a profile with an angle of 40-50 ° for engaging the lower armature with collet petals and compressing the collet petals.

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