RU2294427C2 - Mechanical packer - Google Patents

Abstract

FIELD: oil production industry, particularly to pack well bore, for instance pressure observation wells.

SUBSTANCE: packer comprises mandrel, connection clutch, ram mechanism made as cage with spring-loaded rams and anchor rams, as well as upper and lower expanding cones and packing means. Packer is provided with adapter and extension means connected with each other and with mandrel by shear members. The packer also comprises spring-loaded dies installed in groove formed in the mandrel below sub, cup surrounding adapter and spring-loaded dies, collar enclosing the cup, seating cone enclosing the mandrel, provided with bearing and connected with lower collar end, as well as telescopic control-rod enclosed with packing means. The packer has locking clutch slidably connected with upper expanding cone and seating cone and forming air-tight threaded connection with packer mandrel. The locking clutch encloses connection clutch. Adapter is connected with upper cup end by means of sliding connection. Mandrel ends are provided with grooves adapted to receive corresponding projections of the extension.

EFFECT: provision of well bore packing and reservoir fluid sample taking under packer within perforation interval in the case of shutoff valve inclusion in the packer.

6 dwg

Description

FIELD OF THE INVENTION

The invention relates to the oil and gas industry and is intended for sealing the trunk mainly of piezometric wells.

State of the art

An analysis of the inventive step showed the following: a device is known for sealing the annulus (see US Pat. RF No. 2101461 6 E 21 B 33/12), comprising a stem with a groove, a sealing element mounted on the stem, upper and lower anchoring units, cones with an internal protrusion located respectively above and below the sealing element, a latch in the lower anchor node, a sub on the upper end of the stem.

In the lower and upper parts of the body, the anchor nodes are made in the form of spring-loaded dies.

During the descent of the packer into the well, the centralizers of the anchor nodes are pressed against the wall of the well, the dies are folded inward and their unauthorized movement in the radial direction is excluded.

The packer works as follows:

- when the specified depth is reached, the pipe string with the packer is raised and the latch is inserted into the long part of the groove with unloading of the tool by turning to the right. The rod moves downward relative to the anchor nodes, with the lower cone in contact with the dies and compression of the spring, which leads to their movement to the wall of the well;

- when unloading the tool, the lower protrusion of the rod comes into contact with the additional protrusion of the upper cone and the compression of the spring. The sealing element under the action of a compressive load is deformed to the wall of the well and seals the annulus;

- to transfer the packer to the transport position, remove excess pressure under the package;

- rods with an upper cone and a sealant move down to the stop with the lower cone. Dies force spring return to its original position:

- by pulling the pipes, the compressive load of the packer is removed;

- the dies of the lower anchor node are added;

- the sealant assumes its original position.

The disadvantages of this packer:

- the need to enter under high pressure hydraulic fluid into the tubing string to fit the packer;

- for the conditions of application of the latter in piezometric wells is unacceptable;

- in the case of using the weight of the lift column for landing the packer, it is difficult to disconnect and attach the lift pipe string.

Known packer type PV-YM, consisting of a sealing element mounted on the barrel associated with anchoring and fixing devices (see "Packers, anchors, column disconnectors, tools and accessories for them." Catalog - M .: TSINTIKHIMNeftemash, 1984, p .6).

To fit the packer, the pipe string together with the packer is first raised, and then a finger is removed from the figured groove by turning to the right while lowering it. The stem with a finger moves downward relative to the anchor assembly. As a result, the dies are brought out radially before contact with the casing. With further movement of the packer rod, the sealing element is compressed axially until it contacts the casing wall.

In the proposed device, the tightness is ensured only by transferring the weight of the tubing string. However, in some cases, the weight of the tubing string to fit the packer is not enough. In addition, in the case of using such a packer in piezometric wells, after it is planted, the tubing string is disconnected from the packer and removed to the surface. In this case, after removing the axial load, the sealing element may depressurize and even remove the packer from the installation site. Holding the packer in place is possible using a hydraulic type anchor.

However, provided that the hydraulic type of anchor is used in the arrangement, it becomes necessary to supply pressure fluid to the tubing string with pressure, with appropriate filling of the wells. This is unacceptable in conditions of use in piezometric wells, since they are designed to monitor the operation of the field or underground gas storage. This observation is carried out by measuring the level of reservoir fluid, taking samples and studying their composition. The introduction of the working fluid into the well will distort the results of studies, which is unacceptable. In addition, the hydraulic fit of the packer or anchor assembly involves the use of a ball valve mounted on a saddle connected to the barrel with calibrated shear pins. Under conditions of using the packer in piezometric wells, it is implied that it is equipped with a shutoff valve. This makes it impossible to use a packer with a hydraulic landing method, since a ball with a saddle cannot be dropped to the bottom of the well.

A well-known mechanical packer (see. "Reference manual on the gas-lift method of operating wells." Yu.V. Zaitsev, R. A. Maksutov, O. V. Chubanov and others M., Nedra, 1984, p. 76), consisting of a sealing assembly, a ram mechanism and a retainer. A cone and sealing collars between the cone and the upper stop are freely mounted on the packer barrel. The dies enter the slots of the die holder and are pressed against the cone by springs. Below the location of the detachable cone, a spring lamp housing with shoes and a lock is installed, in which a curly groove is made and a finger connected to the barrel is located.

The packer is lowered into the well to a predetermined depth, then the tension of the lift column is raised by the amount necessary to create the estimated axial load on the packer, and the barrel is turned one and a half to two turns to the right. Due to the contact of the shoes, the lamp housing and the dies do not change their position relative to the casing. When the pipes rotate, the finger slides along the curly groove and lowers down along the long groove.

The cone pushes the dies radially until it contacts the casing.

Then, by loading the weight of the pipes, the cuffs of the seal are compressed.

However, for the conditions of use of such a packer, for example, in piezometric wells, in some cases, after the packer is planted, the pipe lift string is disconnected from the latter by applying left rotation, which can lead to removal from the installation site.

If it is necessary to reconnect the pipe string to the packer by inserting the threaded cone into the coupling thread and transferring the torque sleeve, it is possible to rotate the packer around its axis, which makes it difficult to remove the finger from the long groove and enter it into the curly slot of the lock. This reduces the reliability of the entire device.

Known mechanical packer type PZFM - 146 (see "Geology, drilling and development of gas and gas condensate fields and underground gas storage facilities", OAO Gazprom, OAO SevKavNIPIgaz, Collection of scientific papers. Issue 32, p.137-143. Stavropol, 2001).

The packer consists of a barrel on which a seal is installed, an expanding cone connected with a housing, which is equipped with a bayonet groove in the upper part. A pistol finger is inserted inside the bayonet groove, which in turn is connected with an elevator pipe string. An extension pipe with a shoe flap at the lower end is fixed at the lower end of the packer barrel.

The length of the extension pipe is determined based on the depth of the well and the location of the packer above the perforation interval.

The gun is connected to the body with a shear pin.

The packer is planted as follows: the layout of the filters together with the valve shoe and the packer is lowered into the well until it stops at the bottom.

By right rotation of the elevator string, the pistol pin is withdrawn from the short section of the bayonet groove and loaded — by weight transfer — the expansion cone is inserted into the sealant with the latter deforming in the radial direction to contact with the casing string. The device is locked in this position by inserting the retaining ring on the packer barrel into the reciprocal groove in the housing.

By right-hand rotation of the pipe tubing string, when the gun finger is in the long bayonet groove and pipe tensioning, the tubing string is disconnected from the layout.

If it is necessary to remove the layout from the wells, a gun is installed on the lower cone of the pipe tubing before being lowered into the well and lowered into the well with its introduction into the bayonet groove with fixation in the short part. By pulling the elevator column, the expanding cone is withdrawn from the seal. Further moving up remove the packer from the installation site.

The disadvantages of the design of the packer include: the need to support the layout on the bottom of the well; for the packer to be planted, an extension pipe is required, the length of which can be different and quite large depending on the perforation interval and depth of the wells. However, according to the operating conditions of piezometric wells, the use of an extension pipe between the packer and the bottom is unacceptable, since the results of studies of reservoir fluid samples will be distorted, which may occur when it is located in the wellbore. It also prevents the free migration of fluid in the formation, as well as the ingress of oxides during metal corrosion, into the samples of the formation fluid. The installation of an extension pipe also prevents the packer from being equipped with a shut-off valve.

Known packer (see US Pat. RF No. 2068074, M. CL E 21 B 33/12), consisting of a hollow body with an annular groove and a radial hole, a push sleeve with radial holes, cuffs, cylinder, annular cone, thrust sleeve with an opening, an annular cavity, a ratchet, a retaining ring, dies, a die holder, a coupling on the lower ring with a ball valve seat and a ball connected to the barrel with a calibrated shear element.

Design disadvantage: the need to use a working fluid for the hydraulic packer landing with the subsequent release of the axial channel from the saddle with the ball. According to the conditions for equipping piezometric wells with such equipment, it is unacceptable for the working fluid to enter the bottom of the wells, and samples taken of the formation fluid mixed with the working fluid will distort the research results. In addition, when equipping the wells with such packers, connected at their lower end to the shutoff valve, it is impossible to land them, since when the saddles are thrown off, the ball can get stuck in the axial channel of the shutoff valve body, which is a mandatory device installed on the lower end of the packer barrel .

Known mechanical packer (see AS USSR No. 1667637, class E 21 B 33/12, publ. 07/30/1991), taken by the authors as a prototype for the maximum number of similar structural features.

A mechanical packer consists of a barrel having quick disconnect connections at its ends, a housing with a serrated outer surface in the lower part, connected by the upper part to a thrust sleeve, under which a sealing element is mounted, resting on a spacer sleeve connected to the anchor and fixation unit of the packer, anchor unit and centralizer node. The anchor assembly is made in the form of a guide sleeve, in the windows of which slips are placed between the upper and lower wedge bushings. The lower wedge bush is connected to the hub of the centralizer assembly, in which spring-loaded friction centering pads are mounted. Between the lower wedge bush and the hub of the centralizer assembly, a split stop element with an internal threaded thread is installed to interact with the gear outer surface of the lower part of the housing. Between the outer gear surface of the lower part of the housing and the split locking element, a sliding sleeve with an inner annular protrusion is installed, which is moved by the packer barrel in two directions.

Design disadvantages:

- for planting the packer requires the creation of an axial load, the maximum value of which is determined by the weight of the pipe string. However, in some cases, the weight of the pipe string is not enough to create the necessary load on the seal, especially for gas fields and underground gas storages, which are characterized by shallow depths. Thus, the packer has a restriction on the minimum depth (place) of its installation in the well. In this case, either this packer cannot be used at all or its installation will require additional technical and technological solutions that inevitably complicate the work with it;

- if the packer is used in piezometric wells, as well as if the packer is used to install downhole equipment (shut-off valve, dispersant, etc.), it is necessary to disconnect and remove the pipe string after planting the packer and then connect the pipe string when I will need to eat the packer. In this case, the design of the packer does not provide for the possibility of disconnecting-attaching columns. The use of an intermediate docking device when installing it between the packer barrel and the pipe string is problematic, since the docking device usually requires the application of torque, and rotation can lead to the unscrewing of the quick disconnect connection of the packer and its accidental removal;

- after the packer is planted, the compressive force on the seal is maintained due to the fixed position of the housing meshed with its gear surface with a split locking element. When removing the packer, there is no axial load on the upper part, the split locking element is in a fully loaded state and its forced disengagement can lead to tooth fracture, a sharp, spasmodic movement of the housing, which reduces the reliability of the structure.

Disclosure of invention

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

- the possibility of using the device in conditions of piezometric wells, regardless of the interval of perforation, well depth and the lack of weight transfer of elevator pipes;

- the exclusion of the use of working fluid for packing the packer by creating excess pressure in the pipe pipe string;

- the exclusion of the use for landing packer weight of the tubing string with support on the bottom of the pipe extension;

- the ability to keep the packer in working position when disconnecting from it an elevator pipe string;

- the ability to connect the pipe string to the packer and remove it from the well by applying tensile axial force.

The technical result is achieved using a mechanical packer containing a barrel, a coupling, a ram mechanism in the form of a flashlight with spring-loaded rams and anchor rams, upper and lower expansion cones, a seal, while it is equipped with an adapter and extension cord connected by shear elements to each other and with barrel, spring loaded crackers installed in a groove made in the barrel below the adapter, a glass covering the adapter and spring loaded crackers, a sleeve covering the glass covering the barrel a landing cone having a bearing and connected to the lower end of the sleeve by a telescopic rod covered by a seal, and telescopically connected to the upper expanding cone and the landing cone, forming a tight threaded connection with a barrel locking clutch covering the coupling, the adapter being connected to the upper end of the glass by a telescopic connection, and in the end of the barrel grooves are made, which include mating protrusions of the extension cord.

The landing cone is equipped with a rod installed in the annular gap between the upper regime cone and the barrel, with the possibility of forming a telescopic connection with it. The upper expanding cone is installed with the possibility of interaction with the dies of the anchor installed in the windows of the body, above the location of the lower expanding cone and the flashlight with spring-loaded dies.

The adapter is connected to the barrel and extension cord with calibrated shear elements. The trunk and the extension cord at the ends directed towards each other contain protrusions included in the response grooves. The lower expanding cone is installed in the lamp housing and is connected to the barrel by means of a thread, equipped with a finger entering the longitudinal groove and made in the lamp body above the location of the spring-loaded dies.

An analysis of the inventive step showed the following: the design of a mechanical packer is known (see as.with. No. 1439208. Ml. 4 E 21 B 33/12, publ. 11/23/88. Bull. No. 43), where the rotation to the right is applied to make the packer landing with the transfer of the weight of the tubing string.

Known hydraulic packer (see AS No. 1788207 E 21 B 33/12, publ. 15.01.93, Bull. No. 2), the fixation of which in the casing is carried out by entering the expanding cone under the anchor dies due to weight loading lift pipe columns.

We have not found in the patent and scientific literature a description of the designs of mechanical packers in which torque transmission was used to fix it, to fix the packer inside the casing, followed by radial deformation of the sealant while continuing to transmit torque from the pipe tubing string, s conversion of rotation to axial movement of the barrel and the introduction of the landing cone under the seal.

The constructive mechanical connection of the barrel through the adapter and extension with the connecting sleeve and the telescopic connection of the adapter with a glass covering the spring loaded crackers installed in the annular bore of the barrel were not found, the adapter being connected to the barrel and extension using calibrated shear elements and provided with grooves in the end part facing to the end of the barrel, with mating protrusions included in them.

Also, the presence of an additional lock coupling for reconnecting with an elevator pipe string installed at the upper end of the adapter with the possibility of covering the coupling was not found.

The presence of a telescopic linkage of the thrust associated with the landing cone and the upper expanding cone interacting with the dies of the armature, in the presence of a loaded contact of the latter with the lower expanding cone, was also not found.

Thus, the achieved technical result is due to the unknown properties of the parts of the device in question and the relationships between them.

The invention does not explicitly follow from the prior art, that is, it meets the criterion of inventive step.

Brief Description of the Drawings

The design of the device for overlapping the annular space of the well, mainly piezometric, is illustrated by the following drawings:

- figure 1 shows the design of the mechanical packer in the context, in the initial position;

- figure 2 - the design of the mechanical packer in the position of the constituent elements when the annulus overlap;

- figure 3 - the design of the mechanical packer in the position of disconnecting from it the tubing string;

- figure 4 - the design of the device in the position of connection with the elevator pipe string and removal from the installation site;

- figure 5 - mechanical packer in the position of removing the contact of the expanding cone with the dies of the anchor;

- figure 6 - mechanical packer in the position of the return of the dies of the anchor to its original state and its removal from the well.

The implementation of the invention

The inventive device consists of a barrel 1 connected through an adapter 2 with an extension 3, which are connected to each other by a calibrated shear element 4. The upper end of the extension 3 is equipped with a connecting sleeve 5 for connecting the tubing pipe string.

At the end of the barrel 1, facing the end of the extension 3, grooves 6 are made, which include the mating protrusions 7 of the extension 3. The adapter 2 is equipped with a locking clutch 8, covering the coupling 5, and forms a tight threaded connection with the barrel 1. On the outside, the adapter 2 is covered by a glass 9 and forms a telescopic connection with its upper end. On the trunk 1 of the packer, below the location of the sub 2, an annular groove 10 is made, in which spring-loaded crackers 11 are located, covered by a glass 9.

The adapter 2 and the barrel 1 are connected to each other by a calibrated shear element 12 mounted above the thread connecting the barrel 1 with the adapter 2. The glass 9 is surrounded by a sleeve 13 connected to the lower end with a seating cone 14, covering the barrel 1 and provided with a bearing 15.

At the lower end of the barrel 1, a lantern housing 16 is installed, inside of which an annular spring 17 is located, pressing the dies 18 to the inner wall of the casing. In the gap between the lamp housing 16, a lower expanding cone 19 is installed on the barrel 1, comprising a pin 20, the head 21 of which is located in the longitudinal groove 22 of the lamp housing 16. The lower expanding cone 19 is in contact with the dies 23 of the anchor, which are installed in the windows 24 around the perimeter of the housing 16 of the lamp. From above, the upper expanding cone 25 encompasses the barrel 1, telescopically connected with the rod 26 with the landing cone 14. The rod 26 is inserted into the annular gap 27 between the barrel 1 and the upper expanding cone 25 connected with the extrusion ring 28 into which has the lower end of the seal 29 covering the rod 26. The annular gaps between the barrel 1, the adapter 2 and the landing cone 14 are sealed with sealing rings 30 and 31.

The mechanical packer works as follows.

On the lower end of the first lift pipe, a mechanical packer is installed complete with a shut-off valve (not indicated in the figure) (see Fig. 1) and lowered into the well to a predetermined depth.

During the descent, the dies 18 are constantly in contact with the inner surface of the casing. The right rotation of the pipe tubing, which is communicated to the packer barrel 1, through the interaction of the protrusions 7 at the end of the extension 3, with the mating grooves 6 at the end of the barrel 1. In this case, the lamp housing 16 remains stationary due to the interaction of the spring-loaded dies 18 with the casing. The lower expanding cone 19 with the right rotation of the barrel 1 moves up and interacts with the dies 23 of the armature, which are bent in the radial direction before contact with the wall of the casing. A further rotation of the barrel 1, the latter moves downward relative to the dies 23 of the anchor. At the same time, the cup 9 together with the extension 3 and crackers 11 moves relative to the sleeve 13 until it enters end contact with the bearing 15 in the seat cone 14. When the barrel 1 rotates, the seat cone 14 moves axially and is inserted into the seal 29 with its radial deformation to the wall casing string.

Simultaneously with the landing cone 14, the thrust 26 moves inside the upper expanding cone 25, and the axial force on the dies 23 of the anchor is transmitted from above by the upper expanding cone 25 through the seal 29, which is supported by the extrusion ring 28.

When the packer is fixed by the dies 23 of the anchor, the seal 29 is completely deformed with the landing cone 14 inserted into the inside and hermetic contact with the casing wall is formed. The packer is ready for use. To disconnect the pipe tubing from the packer to the extension 3 through the sleeve 5, an axial tensile force is applied, at which the tared shear element 4 is destroyed and the pipe tubing is removed to the surface (see Fig. 3).

If it is necessary to remove the packer to the surface to the lower end of the pipe tubing string, before lowering into the well, connect a sub (see Fig. 4) with a thread on the cone identical to the thread of the coupling sleeve 8. In the locking sleeve 8, rotate the pipe with the right rotation of the lift column with the application permissible torque, which far exceeds the value of the torque required to twist the adapter 2 with the barrel 1. Left-handed rotation of the pipe pipe string, communicated to the adapter 2, destroy the calibrated the second shear element 12 and unscrew the adapter 2 from the barrel 1.

In this case, the adapter 2 freely moves telescopically relative to the glass 9 and comes into end contact with it. By tensioning the pipe string, the adapter 2 interacts with the glass 9 and moves it upward relative to the barrel 1 and crackers 11. The crackers 11 are spring-loaded from the annular groove 10 on the barrel 1 packer. By further moving the pipe string upward, the adapter 2 through the cup 9 interacts with its end with the sleeve 13 and moves it 14 together with the seating cone 14 and the rod 26 relative to the seal 29 and the upper expansion cone 25 until it enters the end contact with the extrusion ring 28. Further upward movement the adapter 2 together with the landing cone 14 and the rod 26, the latter is introduced into the end interaction with the extrusion ring 28, which leads to the exit from the interaction of the upper expanding cone 25 with the dies 23 of the anchor, which and pulling the lamp body 16 and their interaction with the teeth of the casing wall is disengaged. The lower expanding cone 19 is in end contact with the housing 16 of the lamp, which completely frees the dies 23 of the armature from interacting with the wall of the casing and their entry into the windows 24. Thereby, the packer is freely removed from the well.

Claims (1)

A mechanical packer comprising a barrel, a coupling, a ram mechanism in the form of a flashlight with spring-loaded rams and anchor rams, upper and lower expansion cones, a sealant, characterized in that it is equipped with an adapter and an extension cord connected by shear elements to each other and to the barrel, spring-loaded crackers installed in a groove made in the trunk below the sub, a glass covering the adapter and spring loaded crackers, a sleeve covering the glass, covering the barrel with a landing cone having a bearing and connected to the lower end of the sleeve, a telescopic rod covered by a seal, and telescopically connected to the upper expanding cone and the landing cone, forming a tight threaded joint with a lock clutch covering the coupling, the adapter being connected to the upper end of the cup by a telescopic connection, and grooves are made in the end of the barrel, in which the mating extensions of the extension cord enter.

Images