RU2482263C2 - Thermal packer - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: thermal packer includes a shaft with reducing and connecting couplings, an anchoring assembly in the form of a casing with openings and longitudinal slots, upper and lower expansion cones, spring-loaded plates, a sealing element of the shaft and a sealing element of the packer between upper and lower expansion cover plates. The cover plates are connected through a mandrel to the reducing coupling. Lower expansion cone is provided with a pusher. A threaded nut is installed on outer surface of the pusher. Also, the packer includes an extension piece with sliding blocks in longitudinal openings. Sliding blocks have the possibility of interacting with annular grooves of a threaded sleeve. In addition, the threaded sleeve is equipped with a protective reducer with a projection made on the end part, which faces the side of the connecting coupling. The threaded sleeve has the thread, on which a snap nut with inner bore and annular projection is installed. The projection is equipped with a spring ring with an inner tooth and a slot. The ring is installed so that it can interact with the projection of the protective reducer. The connecting coupling is connected to the shaft through left-handed thread and includes a longitudinal slot on the outside. It is installed so that it can interact with a spring ring and an inner tooth at axial movement of the shaft and the right-handed rotation. Support sleeve is equipped with a limit stop that has the possibility of interacting with the connecting coupling and the extension piece.

EFFECT: possible extraction of thermal packer in case of abrupt increase in axial load on production string of heat-insulated tubes and on the shaft of the packer.

1 cl, 5 dwg

Description

The invention relates to the oil industry and is intended for sealing the annular space mainly geothermal and steam injection wells.

Known mechanical packer (1), consisting of a barrel installed in the axial channel of the housing, seal, expandable cone.

The housing in the upper part is equipped with a bayonet groove into which the pistol pin is inserted, which is rigidly connected to the pipe lift string. An extension pipe is fixed at the lower end of the housing, the length of which depends on the distance between the perforation interval and the face. The bayonet lock pistol is connected to the housing by a shear pin.

Packer landing is carried out by right-handed rotation of the pipe string connected to the barrel, with axial load from the weight of the pipe string pipes, reported to the expanding cone, which is inserted inside the seal, with its radial deformation to the casing wall. The device is locked in this position by inserting a snap ring on the packer barrel into the reciprocal groove in the housing.

If necessary, it is possible to disconnect the pipe lift string from the packer, by transferring the gun finger in the bayonet groove.

Removing the packer is carried out by tensioning the tubing string, with the expansion of the expanding cone from the interaction with the sealant.

Disadvantages of the packer design:

- in the case of replacing the sealant material with a heat-resistant one, for the perception of high temperatures, it is necessary to apply large axial loads to deform them, since the sealant has high rigidity. With a shallow depth of steam injection wells, the weight of the tubing string is not enough.

When the packer rests on the bottom and a sufficiently long length of the extension pipe, in the case of a thermal change in length, there are conditions for an increase in compressive and contact stresses in the seal, as well as for an uncontrolled increase in the torque that must be applied to the packer barrel to ensure its extraction.

During prolonged coolant injection, in addition to axial thermal extensions, additional radial loads act on the sealant, which also negatively affects the device and complicates the extraction of the packer from the well, since the axial loads on the pipe tubing string increase sharply.

Known mechanical packer (2) (see US Pat. No. 4,548,264 Ml. E21B 33/128, NKI 166/130, published October 22, 1985), intended for use in steam injection wells. The packer consists of a barrel, at the upper end of which there is an adapter sleeve, with a longitudinal bayonet groove on the outside. The clutch is covered by the body of the central mandrel. Into the longitudinal grooves are introduced the heads of the fingers rigidly connected with the body of the central mandrel, which covers the trunk and is connected to a spindle equipped with a connecting pipe.

The spindle on the outer end surface is provided with an annular protrusion, on which a threaded lower cover rests, connected with the upper expanding cone through a connecting pipe, which, in turn, is connected with the lower end of the spindle.

A connecting pipe connected to the lower end of the spindle extends along the upper and lower expanding cones of the armature dies and contains an annular protrusion at the lower end.

The lower expanding cone is equipped with a pusher with an internal threaded surface and rests on the annular protrusion of the connecting pipe through a bearing, which plays the role of a supporting surface.

At the lower end of the connecting pipe installed traction, with the formation of an annular gap with the barrel.

Inside the annular gap there is a support bearing with an annular groove and an annular protrusion on the lower ring, connected with the draft by a calibrated shear element. A threaded nut with crackers in its longitudinal grooves included in the reciprocal longitudinal thrust windows is installed inside the pusher. A heat-resistant sealing element is installed between the spindle and the barrel.

A packer seal is installed on the spindle between the bottom cover and the mandrel.

The upper and lower expanding cones are covered by a casing with longitudinal windows, in which the anchor dies are installed, spring-loaded with lantern springs. The other ends of the expanding cones are inserted into the grips resting on the threaded nut. The lower expanding cone is equipped with fingers entering the mating longitudinal windows of the casing.

Mechanical packer

When the packer is lowered into the well, the springs of the spring lamp are in constant contact with the inner surface of the casing pipes.

By the right rotation of the pipe tubing string, which is communicated to the packer barrel, at the end contact of the mandrel and spindle, the rotation is transmitted to the connecting tip and then, through the rod and crackers, to the threaded nut.

Due to the presence of a bearing surface, in the form of a bearing between the lower expansion cone and the protrusion on the lower end of the connecting pipe, it is possible to transmit torque to the threaded nut, which, in the presence of contact of the spring lantern springs with the casing pipe wall, moves the lower expansion cone with entering under the dies of the anchor.

By settling, the upper expanding cone is inserted under the anchor plates, the fingers on the central mandrel move in the longitudinal groove of the adapter. The transmission of torque to the threaded nut is continued and the dies are brought into contact with the inner surface of the casing pipe, the seal is deformed to contact with the wall and formation of tight contact.

Left-handed finger is removed from the short groove of the bayonet lock on the central mandrel and the tension of the pipe string lifts the packer barrel up, with the latter in the neutral position, to compensate for the thermal elongation of the pipe pipe string.

The packer is removed from the installation site by transmitting axial force to the pipe tubing and, through the amplifier, to a calibrated shear pin, which connects the rod to it. This leads to a cut of the calibrated pin and the extension of the extension relative to the traction, with the location of the annular groove at the location of the crackers in the grooves of the threaded nut. In this case, crackers are introduced into the annular groove and exit from the interaction with the body of the threaded nut.

Thereby, the upper expanding cone is brought out of interaction with the anchor dies, which, when further moved upward, comes into end contact with the casing, which moves upward relative to the lower expandable cone by the length of the finger stroke in the longitudinal groove of the casing and the way out of the interaction of teeth of the anchor dies with the pipe casing string. Axial load is removed from the seal, and it returns to its original position.

The disadvantages of the design of the packer include the following:

- when removing the heat-resistant packer from the well, the coupling at the lower end of the barrel enters end contact with the sleeve and moves it relative to the extension with the introduction of crackers into the bore. Further, by pulling up, the anchor dice are returned to their initial position. But when the heat-resistant packer is in the steam injection well for a long time, a scale layer is deposited on the outer surface of the parts, which can serve as an obstacle to the mutual movement of the parts during removal. Axial forces can exceed, in value, the permissible values for the material of the pipes of the elevator column. In this case, emergency work is required at the well with the replacement of the elevator column pipes with stronger ones. But with mechanical contact with the parts of the packer of the coupling at the lower end of the packer barrel, the latter cannot withstand increased axial loads, which can lead to destruction of the barrel.

The known design of heat-resistant packer (see US Pat. RF No. 2.267.003, Ml. E21B 33/12, publ. 12/27/2005. Bull. No. 36), adopted as a prototype.

The device consists of a barrel connected with a transition sleeve equipped with a finger entering the bayonet groove of the mandrel, covered with a bandage. Mandrel, bandage and adapter sleeve are interconnected by a tared shear element. The mandrel is connected to the extension cord through a coupler. The packer is equipped with a sealing element for overlapping the annulus and a mandrel seal between the upper and lower covers, which is connected through the rod to the upper expansion cone, covered by a casing with spring-loaded dies in the longitudinal windows, which are supported by the lower expansion cone, connected, in turn, through the pusher with a threaded nut equipped with a prefabricated stop with a figured protrusion facing the pusher, which is also provided with a figured protrusion. The assembled emphasis contains longitudinal grooves in which crackers are installed, which enter the mating longitudinal windows in the extension cord, supported in this position by a sleeve that is connected to the extension cord by a calibrated shear element and contains an annular groove on the outside. The lower end of the pusher is equipped with a nut and a grip for the centralizer springs. Figured protrusions are installed with the possibility of interaction with each other during the perception of the left rotation of the barrel, and their height is taken less than the thread pitch of the threaded nut. With the right rotation of the barrel, the threaded nut interacts with the pusher and introduces the lower expanding cone under the spring-loaded anchor dies, with their radial movement until they come into contact with the inner surface of the casing pipe and subsequent deformation of the sealing element.

Left-handed rotation of the barrel together with the adapter sleeve remove the finger from the bayonet groove in the body of the mandrel and move the barrel up to the neutral position, with the location of the coupler under focus.

The disadvantages of the design of the heat-resistant packer include the following:

- when the heat-resistant packer is operating in the mode of prolonged coolant injection, a scale layer is deposited on the outer surface of the mating parts, which can lead to a sharp increase in the axial load on the packer’s barrel when it is removed from the well, with the possibility of its destruction. This, in turn, will require complex emergency operations to remove the heat-resistant packer.

The technical result that can be obtained by implementing the invention is as follows:

- the ability to remove the heat-resistant packer, in the case of a sharp increase in axial load on the elevator column of heat-insulated pipes and on the packer barrel, by independently extracting them - disconnecting from the heat-resistant packer and carrying out work associated with connecting to its mandrel a pipe string having higher strength than lift pipe string designed to supply coolant to the reservoir.

The technical result is achieved in that the heat-resistant packer contains a barrel with adapter and couplings, an anchor assembly with dies, upper and lower expandable cones, a sealing element of the barrel, a seal between the upper and lower expandable covers, the lower expandable cone with a pusher, on the outer surface of which is made left-hand thread and threaded nut installed; an extension cord with breadcrumbs in longitudinal grooves mounted to interact with the body of the threaded sleeve in the annular grooves and fixed with a support sleeve associated with the extension shear element. The threaded sleeve is additionally equipped with a protective adapter with a protrusion on the end part facing the coupling, and a thread on which the locking nut is installed, with an internal bore and an annular protrusion on which a spring ring with an internal tooth and a slot is mounted. The spring ring is installed with the possibility of interaction with the protrusion of the protective adapter that enters the slot, and the coupling is connected to the barrel by a left-hand thread, contains a longitudinal groove on the outside and is installed to interact with the ring by the spring and its internal tooth during axial movement of the barrel and right rotation. The support sleeve is provided with a stop made with the possibility of interaction with the coupling and the extension cord.

The analysis of technical solutions selected from the patent and scientific and technical literature showed that the mechanical packer is known (see. "Reference manual on the gas-lift method of operating wells." Yu.V. Zaitsev, R. A. Maksutov, O. V. Chubanov and Dr. M .: "Nedra", 1984, p.76). The packer consists of a trunk connected to an elevator pipe string. An expanding cone and sealing cuffs between the last and upper stops are freely mounted on the barrel.

To transmit torque to the packer barrel, when it is landing, a spring lamp is used, there is a figured bayonet groove in which the finger moves when the packer is landing. It is possible to disconnect the tubing string, if necessary, from the packer by left rotation.

If it is necessary to reconnect the pipe string to the packer, it can rotate inside the production string.

Known mechanical packer (see US Pat. RF No. 2.204.427, Mcl E21B 33/12. Publ. 10.02.2004).

The packer contains a barrel, a coupling, an anchor assembly with dies and expandable cones, a seal. The packer is equipped with an adapter and extension cord, shear elements connected to each other and the barrel, spring loaded crackers in the barrel bore.

Also known is the connection, by means of a thread, of the lower expanding cone with the barrel.

Based on the foregoing and patent research, it can be concluded that we have not identified technical solutions that are based on features that coincide with all the distinguishing features of the claimed technical solution.

It follows that the technical solution does not explicitly follow from the prior art, from which we can conclude that the device meets the criterion of "inventive step".

The design of the heat-resistant packer is illustrated by the following drawings:

figure 1 - design of a heat-resistant packer in the initial transport position;

figure 2 - construction of a heat-resistant packer in the position of interaction of the coupling with the emergency disconnect mechanism;

figure 3 - the relative position of the parts of the emergency disconnect mechanism in cross section, when interacting with the coupling;

figure 4 - design of a spring ring with a tooth;

figure 5 - design of a protective sleeve with a supporting protrusion.

The inventive device consists of a barrel 1, with a connecting sleeve 2 at the lower end and a transition sleeve 3 at the upper. The bandage 4 overlaps the bayonet groove and is connected by a tared element to the mandrel 5, which, in turn, is connected to the extension 6 by the coupling 7. The extension 6 is connected to the upper cover 8, which covers the seal 9 from above, which is pressed by the lower cover 10, connected by a rod 11 with the upper expanding cone 12. The lower expanding cone 13 is in contact with the dies 14 of the anchor assembly installed in the longitudinal windows 15 of the casing 16.

The lower expanding cone 13 is rigidly connected to the pusher 17, which contains a threaded nut 18 at the lower end, which engages with the threaded sleeve 19 by a thread made on its outer surface. At the lower end of the threaded sleeve 19, an assembly stop 20 is installed. The rod 21 of the anchor assembly is connected through a sleeve 22 to an extension 23 extending in the axial channel of the threaded sleeve 19.

In the body of the extension cord 23, longitudinal windows 24 are made, in which crackers 25 are installed, included in the annular grooves 26 (see FIG. 2), made on the inner surface of the threaded sleeve 19. The assembled stop 20 is located on the lower end of the threaded sleeve 19, equipped with a protective adapter 27. A support sleeve 28 is installed between the barrel 1 and the inner surface of the extension cord 23, an annular bore 29 is formed on its outer surface. The support sleeve 28 is provided with a stop 30 and is connected by a shear element 31 to the extension cord 23.

A protrusion 32 (see FIG. 5) is made at the lower end of the protective adapter 27 and a locking nut 33 is installed, with an inner bore 34 and an annular inner protrusion 35, on which a spring ring 36 with an internal tooth 37 and a slot 38 is installed (see FIG. four). A protrusion 32 of the adapter 27 is introduced into the slot 38. A gap 39 is formed between the inner diameter of the spring ring 36 and the outer diameter of the barrel 1.

The coupling 2, at the lower end of the barrel 1, is connected to it through a left-hand thread and provided with a longitudinal groove 40, the dimensions of which are larger than the transverse dimension of the inner protrusion 37 of the spring ring 36.

A longitudinal groove 41 is made in the casing 16, into which a finger 42 is connected, connected with the pusher 17.

At the lower end of the pusher 17, a nut 42 and a holder 43 are installed, which covers the lower ends of the springs 44, the upper ends of which enter into elastic interaction with the dies 14 of the anchor assembly.

Work of a heat-resistant packer

With the adapter sleeve 3, the heat-resistant packer is connected to the lower end of the heat-insulated pipe string and is lowered into the well to the calculated depth. In the process of descent, the springs 44 are in constant contact with the inner surface of the casing pipes.

At the calculated depth, by right rotation, when torque is transmitted to the barrel 1 of the heat-resistant packer, it is planted with the dies 14 of the anchor assembly coming out of the longitudinal windows 15, when the upper 12 and lower 13 expandable cones are inserted under them. The teeth of the dies 14 anchors are brought into contact with the body of the casing pipe. After this, the axial loading of the heat-resistant seal 9 and its radial movement to the wall of the casing pipes, with a tight overlap of the annular gap, are carried out.

By manipulating the lift pipe string (in our case, it is thermally insulated pipes), the barrel 1 is disconnected in the bayonet connection of the heat-resistant packer and it is moved up with the location of the coupling 2 under the locking nut 33. When the coolant is supplied through the heat-insulated pipe lift string, they are heated and thermally elongated , which leads to the movement of the barrel 1 in the axial channel of the thrust 21 of the anchor node.

If it is necessary to remove the heat-resistant packer from the installation site, the heat-insulated pipe lift string is moved together with the barrel until the coupling 2 enters the axial channel of the locking nut 33, with the spring 36 acting on the ring, and its deformation in the radial direction. In this case, the inner tooth 37 (see Fig. 3) comes into contact with the outer surface of the coupling 2. The coupling 2 itself is in end contact with the stop 30 of the support sleeve 28.

When the axial force is calculated, the shear element 31 is destroyed and the support sleeve 28 is moved relative to the extension 23. In this case, the annular bore 29 is located at the location of the crackers 25 in the longitudinal windows of the extension 23. The crackers 25 interact with the body of the threaded sleeve 19 in the annular grooves 26 and are introduced into an annular bore 29, which leads to the termination of the mechanical connection between the extension cord 23 and the threaded sleeve 19 and the conclusion from the interaction of the dies 14 of the anchor assembly with the upper 12 and lower 13 expandable cones. In some cases, it is possible that when pulling the pipe string, the removal force of the heat-resistant packer may exceed the permissible values.

To ensure the extraction of the heat-resistant packer, the pipe lift string, together with the barrel 1, is rotated to the right. In this case, the coupling 2 rotates relative to the spring ring 36 until the protrusion of the inner tooth of the protrusion 37 is inserted into the longitudinal groove 40 on the outer surface of the coupling 2. When the protrusion 32 of the adapter 27 is located in the slot 38 of the spring ring 36, the torque closes to the body of the locking nut 33.

With the right rotation of the barrel 1 and the presence of the left thread in the connection of the coupling 2 and the barrel 1, the coupling 2 is disconnected.

Pulling up the barrel 1 is removed from the heat-resistant packer together with the lift pipe string. This helps prepare the heat-resistant packer for removal, using pipes with higher strength, which are connected to the threads at the upper end of the packer.

Pulling up the heat-resistant packer is removed to the surface.

Claims (1)

A heat-resistant packer containing a barrel with a transition and connecting sleeves, an anchor assembly in the form of a casing with windows and longitudinal grooves, upper and lower expansion cones, spring-loaded rams, a barrel sealing element and a packer seal between the upper and lower expansion caps connected through the mandrel to the transition coupling , lower expanding cone with a pusher, on the outer surface of which a threaded nut is installed, an extension cord with crackers in longitudinal windows installed with the possibility of interaction with annular rings by the points of the threaded sleeve, characterized in that the threaded sleeve is additionally equipped with a protective adapter, with a protrusion on the end portion facing the coupling, and a thread on which a nut is installed that closes with an internal bore and an annular protrusion equipped with a spring ring with an internal tooth and a slot installed with the possibility of interaction with the protrusion of the protective adapter, and the coupling is connected to the barrel with a left-hand thread, contains a longitudinal groove on the outside and is installed to cooperate with the spring and the inner ring teeth upon axial movement of the barrel and the right rotation, and supporting sleeve provided with an abutment adapted to cooperate with coupler and extender.

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