RU2539468C1 - Bidirectional mechanical packer - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: mechanical packer comprises the upper and lower mandrel. The lower mandrel has a closed cam slot at its outer surface. The lower anchor bend is placed at the lower mandrel. The lower anchor bend comprises a body, the lower enclosure with lower spring-actuated pipe arms. In the middle part of the body there are rectangular windows with spring-actuated centralizers placed in them and retained by the upper and lower covers. In the lower part of the body there is a circular outer groove, which connects a split ring to the lower part of the body. The ring has an inner circular groove and an outer plain spigot. A pin lock is installed into the ring. At the upper mandrel there is a support cone pressed to the plain spigot and capable of axial movement. Over the cone there is the lower anti-extrusion unit, seal cups and the upper anti-extrusion unit. The upper anchor bend is placed over it. The upper anchor bend comprises a conical sleeve, a nut, the upper enclosure with the upper pipe arms. Under the pipe arms there is a split cone tied up by locking rings. The cone is supported by the thrust. The thrust is supported by a springy pack consisting of two outermost thrust rings and the middle thrust ring and two split rings placed in-between.

EFFECT: invention allows higher efficiency and operational reliability of the packer.

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Description

The invention relates to the oil and gas industry and can be used in the development and operation of oil and gas wells.

Known packer, which contains the trunk, the upper sub, rigidly connected to the trunk and the lower sub, with which the trunk is connected using a movable keyed connection. The trunk with the upper sub has the possibility of axial movement relative to the lower sub. A sealing element is installed on the trunk between the upper and lower sub, on both sides of which sliding dies are installed between the conical rings. The dies are prefabricated and consist of a body and a lining fixed to it. A set of tightening ring springs is installed in the internal cavities of the dies. The package of dies in the form of a cut sleeve tightened by ring springs is supported by conical surfaces on conical rings. The lower sub is connected to the shank, and the upper sub is connected to the pipe string (RF patent No. 2209926, IPC E21B 33/12, published on 08/10/2003). A disadvantage of the known device is its unreliability in operation due to the fact that the dies without a notch can slide along the production casing, which will lead to movement of the packer and additional load on the tubing, the springs compressing the dies have a small cross section, which can lead to corrosion damage springs with a significant installation time of the packer.

A mechanical packer is known, comprising a barrel with a figured groove on the outer surface with longitudinal short and long sections, a support rigidly connected to the barrel, a sealing element located under it with the possibility of axial movement relative to the barrel, a cone and a clip in which gear slips are evenly arranged around its circumference , a ring mounted in the lower part of the cage and with the possibility of radial rotation relative to the cage, but rigidly connected with it in the axial direction, the cage being fixed the flax of the barrel in the radial direction, the toothed slips are spring-loaded to the barrel and arranged so that upon contact with the cone their inclined flat faces are parallel to the inclined flat faces of the cone, and the guide pin is placed in a figured groove, with the toothed slips placed in a casing that is fixed to a clip having in its middle part grooves in which centralizers with springs are located, fixed in a clip of upper and lower covers, and a split ring is located under the lower cover, on which the guide guide pin (RU 2453679, IPC E21B 33/129, publ. 06/20/2012). The disadvantage of this packer is its low efficiency.

Also known is a mechanical packer selected as a prototype with a closed position lock, consisting of a barrel having a tapered thread on top, a snap ring groove below, a cylindrical protrusion with a figured selection for a closed position lock, and a tapered thread in the lower part in the middle. On the barrel are installed: the upper anchor device, the unit for fixing the closed position, the sealing unit and the lower anchor device. The upper anchor device consists of a spring retainer, a spring sleeve, a spring gasket, a spring casing, an upper spring, a locking ring, a wedge spring sleeve, a wedge spring, a restrictive ring, a housing, a die, a die spring, a wedge, a cone, a cone spring, a cone retainer. The fixation unit of the closed state consists of a support and screws interacting with a curly selection of the barrel. The sealing assembly consists of a barrel seal, a connecting sleeve with rubber rings, an upper conical flange, an upper cuff, metal spacer rings, a middle cuff, a lower cuff, a lower conical flange, and a barrel of a sealing assembly. The lower anchor device consists of a sleeve, cone, housing, dies with springs, a retainer for dies with screws, a retainer sleeve with a retainer (http://www.petrogress.ru, packer with a lock for the closed position, product 20-433). The disadvantages of the packer, taken as a prototype, is the need to rotate the tubing string when installing and removing the packer, which increases operating time, reduces reliability. In addition, this packer is characterized by complexity and high cost of construction.

The task to which the invention is directed is to increase the reliability and efficiency of the packer during its installation, operation and dismantling in oil and gas wells.

The positive effect of the use of the packer in wells is to increase its reliability, increase its service life, increase the well overhaul period and, accordingly, increase the production of fluid.

The technical result is achieved by eliminating the contacts of the dies with the wall of the production casing during the descent of the packer, eliminating emergency situations due to breakage of the springs of the dies, eliminating the movement of the packer along the production casing due to slip of the dies, as well as reducing the complexity of manufacturing the packer and, accordingly, its price while maintaining high performance and reliability.

The problem is solved by a mechanical packer, containing the upper trunk and lower trunk connected by a thread, having a figured groove on its outer surface with longitudinal short and long sections, on which there is a lower anchor assembly including a housing, to which a lower casing is inserted with threads inserted into it and spring-loaded radially lower dies, moreover, rectangular windows are made in the middle part of the housing, in which centralizers are installed, spring-loaded radially and held by the upper and a lower cover fixed to the body by means of screws, and in its lower part an annular external groove is made, by means of which a split ring is connected to the lower part of the body, having an annular internal groove and an external cylindrical protrusion in which a latch is mounted by means of a thread, and on the upper barrel is located with the possibility of axial movement along it and the supporting cone resting on a cylindrical protrusion of the lower trunk, above which there is a lower anti-extrusion unit, of which two metal washers with outer conical surfaces are used, by means of which they interact with a polyurethane ring installed between them, and above the lower anti-extrusion unit there are three rubber sealing cuffs interacting with each other by conical surfaces, over which there is an upper anti-extrusion unit containing a metal washer and a polyurethane ring similar to those located in the lower anti-extrusion unit, and above it there is an upper anchor unit including a cone a clutch fixed by a threaded connection on the upper end of the upper barrel to which the upper casing is attached by means of a nut with the upper dies tightened by the upper spring ring, with a split cone located under the dies in the upper casing, the segments of which are pulled together by two retaining rings, and which rests on an emphasis, which, in turn, rests on a spring pack consisting of two extreme and one middle persistent rings, between which two split rings are located, and which e collectively disposed in a glass having a lower outer tapered surface which forms part of the upper anti-extrusion assembly.

With the help of the lower anchor unit, the packer is kept from moving down, with the help of the upper anchor unit, the packer is kept from moving upwards, thus providing two-way action of the packer.

According to the invention, the figured groove on the outer surface of the lower barrel is closed and has long and short vertical sections, which are connected at the bottom by a triangular-shaped selection, the apex of which is located on a short vertical section, and a protrusion in the form of a parallelogram is made between the long and short vertical sections .

The technical result of the invention is achieved due to the following:

The dies are placed in a casing, which excludes their contact with the walls of the production string when moving the packer along the well to the installation site.

The dies are pulled together by a spring with a significant cross section, which will allow it to perform its function longer in difficult corrosion conditions with a long period of operation in the well.

Installation and removal of the packer is carried out due to its axial movement in the production casing.

The split cone provides a high speed of radial movement of the dies to the wall of the production string when the upper anchor device is triggered, which contributes to reliable contact of the teeth of the dies with the wall of the production string.

With long life of the packer in the well, the upper anchor assembly is covered by sedimented suspended particles from the production fluid of the annulus of the well, which can lead to jamming of the dies of the upper anchor device. In order to prevent jamming of the upper anchor device when removing the packer, the design of the die cover is made with a grip on the conical sleeve, which contributes to the breakdown of jammed dies.

The invention is illustrated by drawings, where figure 1 shows a mechanical packer assembly in the transport position; figure 2 shows the mechanical packer assembly in the working (planted) position; figure 3 - retainer lower anchor device; figure 4 - scan closed figured groove.

The mechanical double-acting packer (Fig. 1) consists of an upper barrel 1 and a lower barrel 2, connected by a threaded connection. The lower barrel 2 is larger in diameter than the upper barrel 1, and a cylindrical protrusion is formed at the junction of the trunks. On the upper end of the upper barrel, a conical coupling 3 is fixed by means of a threaded connection, to which an upper casing 5 is attached by means of a nut 4, in which upper dies 6 are mounted, resting on a wide protrusion of the upper barrel 1. The dies 6 are pulled together by the upper spring ring 7. Below the dies in the upper the casing 5 is located a split cone 8, the segments of which are pulled together by two retaining rings 9. The split cone rests on a stop 10, which, in turn, rests on a spring package consisting of two extreme stop rings 11 and one medium thrust ring 12 between which there are two split rings 13. The emphasis 10 and the spring pack are located in a glass 14 having an outer lower conical surface. All of these parts are located on the upper trunk 1, form the upper anchor node.

Below the upper anchor assembly there is an upper anti-extrusion assembly formed by the lower conical surface of the cup 14, the inner conical surfaces of the polyurethane ring 15 and the outer conical surface of the metal ring 16.

A seal assembly is located under the upper anti-extrusion assembly, consisting of an upper and lower sealing cuff 17 and a middle sealing cuff 18 located between them, the lower cuff of the sealing assembly resting on a lower anti-extrusion assembly similar to the upper anti-extrusion assembly, but containing two metal rings 16.

The lower anti-extrusion unit rests on the support cone 19 of the lower anchor assembly, which is located on the lower barrel 2 and which includes: support cone 19, housing 20, to which the lower casing 21 is connected from above on the thread and is secured against unscrewing by screw 22. In the casing windows 21 are located lower dies 23, which are in the transport position pressed against the lower barrel 2 by means of springs 24. In the lower part of the housing 20 there are rectangular windows in which centralizers 25 with springs 26 are located. Centralizers 25 are held in the housing 20 and using the upper 27 and lower 28 covers connected to the housing by a thread and secured against turning by screws 22 and 29. A split ring 30 is attached to the lower part of the housing 20 with a retainer 31 held by the screw 32 to prevent unscrewing. The halves of the split ring 30 are connected by screws 33 (Fig. .3).

To reduce the attenuation of the lower trunk, a closed figured groove is used (Fig. 4), which consists of a long vertical section I (working position) and a short vertical section II (transport position). In the lower part, the vertical sections are connected by a selection having a triangular shape. The top of the triangular selection is located on a short vertical section and the side adjacent to the top is located vertically, being a continuation of the outer contour of the short vertical section. The side adjacent to the apex of the triangular selection on the other hand forms an acute angle with a short vertical section, and a blunt one with a long section. The base of the triangular selection forms an acute angle with a long vertical section, and a dull angle with a short one. The upper part of the short vertical section is completed by an inclined section III located at an acute angle to the short vertical section. The upper part of the inclined section is located between the short and long vertical sections and is made in the form of a triangular ledge, one side of which is located vertically, and the second one forms an acute angle with the long vertical section. Between the long and short vertical sections is a protrusion IV, made in the form of a parallelogram. The outer vertical sides of the protrusion are the inner vertical sides of the short and long vertical sections. The upper side of the protrusion is adjacent to a short vertical section, forming an acute angle inside the parallelogram. The lower side of the protrusion is the base of the triangular selection and forms with a short vertical section an obtuse angle inside the parallelogram.

The mechanical double-acting packer works as follows.

Before the descent into the well, the packer is in a vertical position (figure 1), the latch 31 is in point A of the closed groove (figure 4). This position of the latch 31 in the closed groove is due to the weight of the parts of the lower anchor assembly (Fig. 1). The descent of the packer into the well is carried out using tubing (tubing). When the packer enters the wellhead, the centralizers 25 interact with the walls of the production string 34 (FIG. 2) and do not allow the lower anchor assembly to move down until the combined force of the springs 26 is overcome by the weight of the descent tubing. Thus, the lower anchor node will stop at the entrance to the production casing of the well 34 (figure 2), and the trunks 1 and 2 with all the nodes located on them will continue to move down. At the same time, the latch 31 will move along the short vertical section II (figure 4), then along the inclined section III until it reaches point B. At this point, the movement of the trunks 1, 2 (figure 1) relative to the lower anchor node will stop and they will start moving down together. In this case, the springs 26 are compressed, providing constant contact of the centralizers 25 with the walls of the production casing 34 (Fig.2) of the well. This position of the packer parts will be maintained until the descent tubing is installed on the wedge suspension. After screwing the next lowering tubing to the previous tubing string on the wedge suspension, the tubing string should be raised to remove from the wedge suspension to a height equal to or slightly higher than NT (Fig. 4), which will ensure the transport position of the lower anchor assembly. When lifting the tubing string, the following occurs: the lower anchor assembly (Fig. 1), held on the walls of the production string 34 (Fig. 2) by the centralizers 25 pressed against it, will remain in place. Trunks 1, 2 will begin to move upward relative to the lower anchor assembly that is in place. At the same time, the latch 31 from point B (FIG. 4) will move downward relative to the barrel 2 (FIG. 1) until it contacts the protrusion IV (FIG. 4) at point B, after which the latch 31 will move obliquely along the upper side of the protrusion IV (FIG. .4), along the long vertical section I, the inclined side of the lower sample, forming with a long groove an obtuse angle to point A.

After removing the tubing string from the wedge suspension, it descends, and trunks 1, 2 move downward relative to the lower anchor assembly. This movement will continue until the latch 31 reaches point B (figure 4). After that, the trunks 1, 2 and the lower anchor node (Fig. 1) will begin to move down together before installing the next descent tubing on the wedge suspension. Thus, when transporting the packer down, the latch 31 will move in a closed circuit from point B (Fig. 4) along the upper side of the protrusion, the long vertical section to point A, then along the short vertical and inclined sections to point B, ensuring the transport position of the lower anchor node (figure 1).

When the packer reaches the planned installation interval, the lower anchor unit should be transferred from the transport position to the working position by the following manipulations: raise the tubing string to a height not exceeding Нр (Fig. 4). At the same time, the latch 31 (Fig. 1) will move from point B (Fig. 4) down to contact with the protrusion IV, on the upper inclined side of the protrusion IV to a long vertical section, along a long vertical section not lower than point G. Switching from the transport position to the working can be carried out from point E to point G. When the latch 31 is located between points E and G, the tubing string should be lowered before installing (planting) the packer. At the same time, the latch 31 (figure 1) will move up the long vertical section I (figure 4), trying to reach point D. Details of the packer will change their position as follows: trunks 1, 2 (figure 1), the upper anchor assembly, the upper anti-extrusion assembly, the sealing assembly, the lower anti-extrusion assembly, the support cone 19 will move downward relative to the lower anchor assembly that is in place. In this case, the support cone 19 will move downward relative to the lower anchor assembly that is in place until it is in contact with the dies 23, which, under the action of the support cone 19, overcoming the force of the springs 24, will begin to radially expand until they come into contact with the wall of the production casing 34 and fix on it. At the same time, the force of the weight of the tubing string being lowered, perceived by the upper barrel 1, will be transmitted through a narrow protrusion of the upper barrel interacting with the split cone 8 to the glass 14 and the upper anti-extrusion assembly, consisting of the conical lower part of the glass 14, a polyurethane ring 15 and a steel ring 16 , further to the seal assembly, the lower anti-extrusion assembly and the support cone 19, fixed relative to the wall of the production string 34 by the lower anchor assembly. The polyurethane rings 15 of the anti-extrusion units, moving radially along the conical surfaces of the steel rings 16, will close the gaps between the support cone 19, the cup 14 and the wall of the production casing 34 and prevent leakage of the rubber of the sealing cuffs 17. The force of the weight of the casing string will deform the sealing cuffs 17 and 18 so that they begin to fill the space bounded by the wall of the production string 34 and the upper and lower anti-extrusion nodes, dividing the internal space of the operation column 34 to a hermetically segregated over-packer and under-packer space.

In this case, the split cone 8 will remain pressed against the upper barrel 1 until the total force of the elastic elements of the seal assembly and anti-extrusion assemblies exceeds the total effort of the split rings 13, retainer rings 9 and friction forces. At this moment, the following change in the relative position of the parts of the upper anchor assembly will begin: the segments of the split cone 8 will begin to move radially along the inclined conical surface of the narrow protrusion of the upper barrel 1 and the stop 10, overcoming the resistance forces of the locking rings 9, split rings 13 and friction forces, until reaching the cylindrical part of the narrow protrusion of the upper barrel 1. At this moment, the split cone 8 under the action of the resistance forces of the elastic elements of the upper and lower anti-extrusion nodes, the seal assembly will begin instantly e short accelerated axial movement towards the upper barrel 1 and dies 6. Under the action of the moving cones of the split 8 and the conical coupling 3, the dies 6, overcoming the force of the upper spring ring 7, will begin to move radially to the wall of the production casing 34 (figure 2) before cutting into it and fixing the upper anchor assembly on it.

To dismantle the packer, it is necessary to lift the tubing string. In this case, the following movements of the packer parts will occur: trunks 1 and 2, the conical sleeve 3 will move upward, releasing the dies 6, which, under the action of the upper spring ring 7, move radially to the barrel 1 and come out of contact with the production casing 34 (Fig. 2) . At the same time, the working gap hp (Fig. 1) is excluded, which facilitates the interaction of the protrusion of the conical sleeve 3 with the nut of the casing 4 to provide additional force, contributing to the separation of the dies 6 and the wall of the production casing 34 (Fig. 2). At the same time, the segments of the split cone 8 (FIG. 1), retainer rings 9, stop 10, stop rings 11, split rings 13, parts of anti-extrusion units 15, 16 and seal assembly 17, 18, support cone 19, which will enter in contact with the cylindrical protrusion of the barrel 2. Under the action of the spring 24, the dies 21 will come out of contact with the wall of the production casing 34 (Fig.2) of the well and will be pressed against the lower barrel 2. At the same time, the latch 31 will move along the long vertical section IV (Fig.4) inclined h part of the lower sample to point A. After that, the movement of trunks 1 and 2 (Fig. 1) relative to the lower anchor node will stop and they will move together upward until the tubing string is mounted on the wedge suspension, which is accompanied by the tubing string moving down. At this time, the lower anchor assembly is fixed on the production casing 34 (Fig. 2) using centralizers 25, and the trunks 1 and 2 are moved down, the latch 31 will move from point A (Fig. 4) along a short vertical section II, inclined section III to point B, providing the transport position of the lower anchor unit when lifting the packer from the well.

The proposed design of the packer allows the installation of the packer by axial manipulations of the tubing string, dismantling due to the tension of the tubing string, eliminating the contacts of the dies 6 and 23 with the wall of the production string 34 (figure 2) during transport of the packer to the installation site, exception jamming of the dies 6 of the upper anchor unit during dismantling of the packer, eliminating emergency situations due to breakage of the springs 26 of the centralizers 25, which generally improves the reliability of the packer and reduces s time and cost of repair and operation of the well.

Thus, the invention improves the reliability and efficiency of the packer during its installation, operation and dismantling in oil and gas wells.

Claims (2)

1. A mechanical packer, comprising a threaded upper barrel and a lower barrel, having a shaped groove on its outer surface with longitudinal short and long sections, on which there is a lower anchor assembly including a housing to which a lower casing is inserted by thread and inserted into it and spring-loaded radially lower dies, and in the middle part of the case there are rectangular windows in which centralizers are installed, spring-loaded radially and held by the upper and lower covers, on the body by means of screws, and in its lower part an annular external groove is made, by means of which a split ring is attached to the lower part of the body, having an annular internal groove and an external cylindrical protrusion, into which a latch is mounted by means of a thread, and axially axially mounted on the upper barrel moving along it and resting on a cylindrical protrusion of the lower trunk, a support cone, above which there is a lower anti-extrusion unit, which includes two metal washers with outer conical surfaces by means of which they interact with a polyurethane ring installed between them, and above the lower anti-extrusion unit there are three rubber sealing cuffs interacting with each other by conical surfaces, over which there is an upper anti-extrusion unit containing a metal washer and a polyurethane ring similar to those located in the lower anti-extrusion unit, and above it is located the upper anchor unit, including a conical sleeve, fixed in the middle threaded connection on the upper end of the upper barrel, to which the upper casing is attached by means of a nut with upper dies inserted into it, tightened by the upper spring ring, and under the dies in the upper casing there is a split cone, the segments of which are pulled together by two retaining rings, and which rests on the stop , which, in turn, rests on a spring pack consisting of two extreme and one middle thrust rings, between which two split rings are located, and which are all together located in a hundred cane having an outer lower conical surface, which is part of the upper anti-extrusion unit. 2. The mechanical packer according to claim 1, characterized in that the figured groove on the outer surface of the lower trunk is closed and has long and short vertical sections, which are connected at the bottom by a triangular-shaped selection, the apex of which is located on a short vertical section, and between the long and short vertical sections made a protrusion in the form of a parallelogram.

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