RU2709585C1 - Combined seal for column head in well on shelf - Google Patents

Abstract

FIELD: sealing.

SUBSTANCE: invention relates to means for sealing of annular gaps between conductor and installed in it suspension of technical string of pipes during operation of wells on shelf. Combined seal is made with two-stage seals and has housing 7 of H-shaped profile in form of two rings 8, 9 with transverse web 10 for their connection and pusher 15. Housing 7 comprises three contact surfaces: inner surface 11 and outer surfaces 12 and 13 in contact with landing conical surface 5 of suspension 3 with equal inclination angle 6 relative to well axis to 10 degrees. Contact length of surface 11 is greater than the total contact length of surfaces 12 and 13. Surface 11 and surfaces 12 and 13 form the first stage of metal-metal seal. Besides, housing 7 is provided with thrust 14 with locking spring ring 16 fitted on pusher 15 to retain housing 7 from axial displacement downwards. Between housing 7 and pusher 15 there is side gap 17 to allow displacement of housing 7 relative to pusher 15 in radial direction. Besides, pusher 15 is rigidly connected with housing 7 by shear element 18. Between pusher 15 and housing 7 there is an external seal of high elasticity 19 for sealing of the surface of conductor 1, and for sealing of suspension 3 there is an internal sealant of lower elasticity 20. Sealant 19 and seal 20 form together second stage of seal – elastic elastomer seals. Besides, pusher 15 is provided with retainers in form of split resilient rings 21 and 22 to interact with fixing slots 2 and 4 and lock 23.

EFFECT: improving sealing reliability of conductor and suspension of technical pipe string during well operation on shelf and simplification of technological operations.

3 cl, 3 dwg

Description

The invention relates to a combination seal used to seal annular gaps between the conductor and the suspension of the technical pipe string installed in it when operating wells on the shelf and made with two-stage seals: the first stage is metal-metal seals, and the second stage is elastic seals.

Known use in wellhead equipment for wells of elastic seals containing rubber cuffs of various shapes and sizes, RU No. 2435931 C1, EV 33/04, 12/10/2011; RU No. 2162929 C2, ЕВВ 33/04, 02/10/2001.

Known suspension of tubing of wellhead valves with metal-to-metal seals installed in the housing of the pipe head, consisting of a housing, seals, having annulus seals in the form of support, retaining rings and metal cuffs with conical inner and cylindrical outer surfaces, RU No. 2171358 C2, E21B 33/04, 07/27/2001.

Known column head containing a cylindrical body, a cover, nozzles, a wedge-shaped suspension in the form of a cut sleeve, elastic lower and upper cuffs and an annular metal seal, RU No. 2146000 C1, ЕВВ 33/04, 02.27.2000.

Known devices for sealing the annular space of subsea wells, including combined seals, US 2013/0000920 A1 ЕВВ 33/035, ЕВВ 33/00, Е21В 33/128, 01/03/2013.

A known sealing system of an underwater drilling rig, US 7073591 B2, E21B 33/043, 07/11/2006; US 6520263 B2, E21B 33/035, 02/18/2003.

In the known devices, features identical to the claimed invention were not found.

The closest analogue to the claimed invention is not found.

The present invention is based on the solution of the problem, which allows to increase the reliability of sealing the conductor and suspension of the technical pipe string during operation of the well on the shelf and simplify the process.

The technical result of the present invention is the reliability of sealing the annular gaps between the conductor and the suspension of the technical pipe string by performing a seal with two-stage seals: the first stage is metal-metal, the second is an elastic elastomeric seal, in the design features of each stage, in simplifying the installation process the seal itself, as well as during operation.

According to the invention, the combined seal for the casing head in the well on the shelf provides sealing of the annular gaps between the conductor and the suspension of the technical pipe string installed therein. The conductor and suspension of the technical pipe string have locking grooves, respectively.

The seal is made with two-stage seals.

The seal has a housing and a pusher.

The housing has an H-shaped profile in the form of two rings with a transverse jumper for connecting the rings.

The housing contains three contact surfaces.

One of the contacting surfaces is the inner surface.

The inner surface is in contact with the landing conical surface of the suspension of the technical pipe string.

The inner surface is made with the same angle with the landing conical surface of the inclination relative to the axis of the well up to 10 degrees.

Two other contacting surfaces - the outer surfaces are in contact with the conductor.

Moreover, the contact length of the inner surface is greater than the total contact length of the outer surfaces.

The inner surface and outer surfaces form the first stage of the metal-metal seal.

In addition, an emphasis is made on the casing with a locking spring ring.

A snap ring is mounted on the push rod to hold the housing from axial displacement down.

And between the housing and the pusher, a lateral clearance is made to allow the housing to be offset relative to the pusher in the radial direction.

In addition, the pusher is fixedly connected to the housing by a shear element.

And between the pusher and the body an external sealant of high elasticity is installed to seal the surface of the conductor, and to seal the suspension of the technical pipe string, an internal sealant of lower elasticity is installed.

The outer seal of high elasticity and the inner seal of lower elasticity together form the second stage of sealing - elastic elastomeric seals.

The outer seal of high elasticity and the inner seal of lower elasticity differ from each other in the geometric form of execution.

The outer seal of high elasticity and the inner seal of lower elasticity differ from each other in different types of material.

In addition, the pusher is made with latches in the form of split elastic rings with the possibility of interaction with the locking grooves, respectively.

In addition, the pusher is made with a lock with the ability to control the latches.

In this case, the transverse jumper connecting the rings of the housing is located between the conditional midpoint of the inner surface and the conditional midpoint of the location of the outer surfaces.

The applicant has not identified sources containing information about technical solutions identical to the present invention, which allows us to conclude that it meets the criterion of "novelty."

Due to the implementation of the distinguishing features of the invention (in conjunction with the features indicated in the restrictive part of the formula), important new properties of the object are achieved.

The implementation of the seal with two stages of seals increases the reliability of sealing the gap between the conductor and the suspension of the technical pipe string.

A structural embodiment of the housing with three contacting surfaces, in which the internal contacting surface has an angle equal to the angle of the landing conical surface of the suspension of the technical pipe string and is in contact with it at a length greater than the contact length on the surface of the conductor, ensuring pressure uniformity at the contact points, which increases the tightness reliability .

The structural design of the housing of the H-shaped profile in the form of two rings connected by a transverse jumper located between the conditional midpoint of the inner contact surface and the conditional midpoint of the location of the outer surfaces provides an even distribution of forces between three points when exposed to any of them.

Placing the housing on the pusher with lateral clearance allows not to act on the plunger, and to transfer the radial force to the external contact ones when installing the sealant (in case of expanding the housing from the load, when approaching the conical surface with a small angle of attack (up to 10 degrees) of the suspension of the technical pipe string) surface.

The connection of the housing and the pusher with a shear element allows you to bring the first stage of the seal to the installation site without accidental deformation of the elastic elements of its second stage, which increases the reliability of the installation of the seal.

The presence of a locking spring ring on the plunger allows (in the case of a seal lifting) lifting of the housing at the wellhead, while guaranteeing the reliability of this operation.

The execution of the second stage of seals with different elasticities, achieved by using materials of different elasticities or of different geometric shapes, allows the external sealant of high elasticity to seal the surface of the conductor, and the internal sealant of lower elasticity to use to seal the suspension surface of the technical pipe string, which is more reliably sealed by the first stage of sealing metal -metal, which increases the reliability of the seal.

The applicant is not aware of any publications that would contain information on the influence of the distinguishing features of the invention on the achieved technical result. In this regard, according to the applicant, it can be concluded that the claimed technical solution meets the criterion of "inventive step".

The invention is illustrated by drawings, which depict:

figure 1 - Combined seal for the column head in the well on the shelf, the installation of the seal, section;

in FIG. 2 - Combined seal for the casing head in the well on the shelf, installation of the seal is completed, section;

in FIG. 3 - Combined seal for the casing head in the well on the shelf, node A in FIG. 1.

In FIG. 1-3 shows:

Conductor - 1,

fixing groove (in the conductor 1) - 2.

Suspension of a technical pipe string - 3,

fixing groove (on the suspension 3) - 4,

landing conical surface (pendants 3) - 5,

tilt angle (surface 5) - 6.

The body of the H-shaped profile in the form of two rings with a transverse jumper - 7,

one ring (body 7) - 8,

the second ring (body 7) - 9,

transverse jumper (body 7 for connecting rings 8 and 9) - 10

The internal contact surface (of the housing 7, conjugated with the surface 5) - 11.

The outer contact surface (housing 7, coupled with the conductor 1) - 12.

The external contacting surface (housing 7, conjugated with the conductor 1) - 13.

An emphasis (on the case 7) - 14,

Pusher - 15,

locking spring ring (on the pusher 15 for an emphasis 14) - 16.

Side clearance (displacement of the housing 7 relative to the pusher 15 in the radial direction) - 17.

Shear element (for fixed connection of the housing 7 and the pusher 15) - 18.

External sealant of high elasticity (between the pusher 15 and the housing 7 for sealing the surface of the conductor 1) - 19.

An internal seal of less elasticity (between the pusher 15 and the housing 7 for sealing the suspension of the technical pipe string 3) - 20.

The latch in the form of a split elastic ring (pusher 15, interacting with the groove 2) - 21.

The latch in the form of a split elastic ring (pusher 15, interacting with the groove 4) - 22.

The lock (to control the latches 21 and 22) - 23.

The combined seal for the casing head in the well on the shelf provides sealing of the annular gaps between the conductor 1 and the suspension of the technical pipe string 3 installed in it. The conductor 1 and the suspension of the technical pipe string 3 have fixing grooves 2 and 4, respectively.

The seal is made with two-stage seals.

The seal has a housing 7 and a pusher 15.

The housing 7 has an H-shaped profile in the form of two rings 8, 9 with a transverse jumper 10 for connecting the rings 8 and 9.

The housing 7 contains three contact surfaces.

One of the contacting surfaces is the inner surface 11.

The inner surface 11 is in contact with the landing conical surface 5 of the suspension of the technical pipe string 3.

The inner surface 11 is made with the same angle of inclination 6 with the landing conical surface 5 relative to the axis of the well up to 10 degrees.

Two other contacting surfaces - the outer surfaces 12 and 13 are in contact with the conductor 1.

Moreover, the contact length of the inner surface 11 is greater than the total contact length of the outer surfaces 12 and 13.

The inner surface 11 and the outer surfaces 12 and 13 form the first stage of the metal-metal seal.

In addition, on the housing 7 there is a stop 14 with a snap ring ring 16.

The castle spring ring 16 is mounted on the pusher 15 to hold the housing 7 from axial displacement down.

And between the housing 7 and the pusher 15, a lateral gap 17 is made to enable the housing 7 to be displaced relative to the pusher 15 in the radial direction.

In addition, the pusher 15 is fixedly connected to the housing 7 by a shear element 18.

And between the pusher 15 and the housing 7 an external sealant of high elasticity 19 is installed to seal the surface of the conductor 1, and for sealing the suspension of the technical pipe string 3 an internal sealant of lower elasticity 20 is installed.

The outer seal of high elasticity 19 and the inner seal of lower elasticity 20 form together the second stage of sealing - elastic elastomeric seals.

The outer seal of high elasticity 19 and the inner seal of lower elasticity 20 differ from each other in geometric form or in various types of material.

In addition, the pusher 15 is made with latches in the form of split elastic rings 21 and 22 with the possibility of interaction with the locking grooves 2 and 4, respectively.

In addition, the pusher 15 is made with a lock 23 with the ability to control the latches 21 and 22.

In this case, the transverse jumper 10 connecting the rings 8 and 9 of the housing 7 is placed between the conditional midpoint of the inner surface 11 and the conditional midpoint of the location of the outer surfaces 12 and 13.

The installation of the combined seal is as follows.

The sealant is lowered into the well on a special tool, which, after imparting maximum weight load, is disconnected and lifted to the platform.

As soon as the inner contacting surface 11 touches the landing conical surface 5 on the suspension of the technical pipe string 3 (Fig. 1), a force will appear perpendicular to the axis of the well.

With further axial load of the tool through the pusher 15, the load will be received by the shear element 18.

The contacting surface 11 with tension will sit on the landing conical surface 5, a shear element 18 will be cut.

The pusher 15 will begin to deform the outer seal of high elasticity 19 and the inner seal of lower elasticity 20.

The force during the deformation of the outer 19 and inner 20 seals is transmitted to the housing 7, it will be elastic deformation in the radial direction.

The housing 7, choosing a lateral gap 17, will press the outer contacting surfaces 12 and 13 to the jig 1.

At this moment, the lock 23 will work, which will push the clamps in the form of split elastic rings 21 and 22 into the fixing grooves 2 and 4 on the conductor 1 and the suspension of the technical pipe string 3, thereby fixing the seal, connecting the conductor 1 and the suspension of the technical pipe string 3 with a rigid connection through the pusher 15.

The tool automatically detaches and rises to the platform.

Seal installation is complete.

To remove the seal, use another tool that grabs the lock 23 and raises it axially upward.

The proposed “Combined seal for the casing head in the well on the shelf” can be manufactured industrially, which is confirmed by the design and technological studies of the main strength characteristics in structural units, and testing of prototypes, studying and substantiating the operating conditions of the proposed technical solution determines, according to applicant, compliance with his criterion of "industrial applicability".

The proposed technical solution allows to increase the reliability of sealing the conductor and suspension of the technical pipe string during the operation of the well on the shelf and to simplify the process operations.

Claims (3)

1. The combined seal for the casing head in the well on the shelf, providing sealing of the annular gaps between the conductor and the suspension of the technical pipe string installed in it, the conductor and the suspension of the technical pipe string having locking grooves, respectively, characterized in that the seal is made with two-stage seals and has a housing and a pusher, and the housing has an H-shaped profile in the form of two rings with a transverse jumper to connect the rings, contains three contacting surfaces and, of which one - the inner surface in contact with the landing conical surface of the suspension of the technical pipe string, is made with the same angle of inclination relative to the axis of the well up to 10 degrees, and the other two are the outer surfaces in contact with the conductor, and the contact length of the inner surface is greater than the total contact length of the outer surfaces forming the first stage of the metal-metal seal, in addition, an emphasis is made on the body with a locking spring ring mounted on the push rod for holding the casing from axial displacement downward, and a side clearance is made between the casing and the pusher to allow the casing to move relative to the pusher in the radial direction, in addition, the pusher is fixedly connected to the casing by a shear element and an external high-elasticity seal is installed between the pusher and the casing to seal the surface of the conductor and for sealing the suspension of the technical pipe string installed an internal sealant of lower elasticity, forming together the second stage of the seal - other elastomeric seals, and, in addition, the pusher is made with clamps in the form of split elastic rings with the possibility of interaction with the locking grooves, respectively, and with a lock with the ability to control the clamps, while the transverse jumper connecting the rings of the housing is located between the conditional middle of the inner surface and the conditional midpoint of the location of the outer surfaces. 2. The combined seal according to claim 1, characterized in that the outer seal of high elasticity and the inner seal of lower elasticity differ from each other in geometric form. 3. The combined seal according to claim 1, characterized in that the outer seal of high elasticity and the inner seal of lower elasticity differ from each other in different types of material.

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