RU2455454C1 - Tubing anchor for electric centrifugal pump - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: device consists of upper and lower adapters, shaft with support ring rigidly fixed in its upper part, shock-absorbing unit with cone and anchoring mechanism located at the shaft with the possibility of interaction. At the shaft below the cone there is a cam slot that has axial short and long areas with guiding pin in it. The cone is made in a form of outer two-step annular recess. Anchoring mechanism is made in a form of a collet, spring-loaded from outside, with guiding pin. Longitudinal short and long areas of cam slot are interconnected by closed shaped area in such a way that in the course of collet reciprocating movement relatively the shaft the guiding pin will be located either in longitudinal short area of cam slot - transport position, when collet interacts with bottom end of the lower step of outer stepped annular recess of the cone, or in longitudinal long area of cam slot - operating position. The collet interacts with the bottom end of the upper step of outer stepped annular recess of the cone. Shock-absorbing element is made in a form of a compression spring. Between the shaft and upper adapter there installed is a sludge and cable bands catching chamber plugged from below.

EFFECT: increasing of operating stability of the device.

2 dwg

Description

The invention relates to the oil industry and can be used in the process of oil production by electric centrifugal pumps to prevent them from falling onto the bottom of the well.

A device is known for preventing the fall of the column of lifting pipes with an electric submersible pump at the bottom of the well (copyright certificate SU No. 1541373, MPK8 Е21В 23/00, 31/00, 1990), comprising an anchoring unit and a drive mechanism made in the casing string, made in the form of a spring-loaded roller mounted at the wellhead with the possibility of interaction with a column of lifting pipes of a spring-loaded roller with an electric current generator installed under an electric submersible pump with the possibility of interaction of a pair of casing with a casing string but the spring-loaded additional rollers having at least one electric current generator, the anchoring unit is made in the form of a conical ram grip, a rod placed under it with the main and additional electromagnets of opposite action located on it, and the movable ram grip wedges are pivotally connected by means of bars to the rod, and the generators of the main and additional rollers are electrically connected to each other through the cable of the electric submersible pump and the cable collector Rabban.

The disadvantage of this device is its unreliability in operation due to the use of an electrical circuit in the control of the anchoring mechanism, namely:

- the probability of failure of the electrical system due to its operation in an aggressive environment, which can lead to breakdowns of electrical components;

- unreliability of contact connections;

- possible damage to the wires during tripping and in an aggressive environment;

- the presence in the well of deposits that lead to the jamming of the rollers, their further slippage, and, as a result, failure of the electric current generator.

The absence of a shock-absorbing unit can lead to breakdown and breakage of the anchor mechanism from impact or crushing of device parts.

Also known is a device for preventing the fall of underground equipment at the bottom of a well, for example a submersible electric pump (copyright certificate SU No. 874968, EV 21/00, 31/00, 1990), containing a barrel with an annular protrusion, support and safety rings mounted on the barrel the shock absorbing assembly and the anchor mechanism are interactable, the shock absorbing assembly being made in the form of a sealing element with a cone mounted under the support ring, and the anchoring mechanism is made in the form of a movable sleeve with a window E, which are installed above the annular protrusion placed balls barrel.

The disadvantages of this device are:

- firstly, the absence of a rigid fixation of the tool when it breaks, the absence of a hard stop of the tool during a fall - it only slows down the drop, amortizes, and if there is deposits on the walls of the production string, with insufficient viscosity of the flushing fluid in the well, the anchor mechanism slides under the weight of the dangling tool , which ultimately ends up at the bottom of the well, with a break in the cable of the electric submersible pump. And vice versa, with a high viscosity of the fluid located in the well, when the tool is lowered, premature spontaneous operation of the device is possible, which will lead to its jamming;

- secondly, during the operation of the electric centrifugal pump, vibration is generated, and this device, being in contact with the column wall, does not limit the degree of freedom of the instrument, vibration vibrations during the pump operation are not suppressed, which leads to weakening of the threaded connections of the tubing string and, as consequence, a break in the tool.

The closest in technical essence to the proposed one is an anti-flying device (patent RU No. 2175048, IPC8 ЕВВ 23/00, published in bulletin No. 29 of 10/20/2001), containing the upper and lower sub, the trunk with its upper part installed supporting ring located on the barrel with the possibility of interaction of the shock absorbing node with the cone and the anchoring mechanism, while on the barrel below the cone there are symmetrical figured grooves having short and long sections, interconnected by a transition section with an angle of inclination of 45 °, and The section is made from the lower part of the cone to the lower sub, the length of the short section is twice the length of the minimum tool detonation during tripping, and the distance from the lower part of the cone to the upper part of the short section of the curly groove is equal to the height of the anchor mechanism, in addition, in the curly groove when the transition section enters the long one, the single-acting locking device is installed, and a shear pin is installed in the through hole made in the cone and the barrel, while the anchor mechanism m consists of a housing located on the barrel with the possibility of axial displacement, installed uniformly around the circumference of the housing and spring-loaded double action grippers relative to it, in the lower part made in the form of a feed cam and in the upper having teeth, a ring mounted on the body, encircling the grippers and being the axis relative to which the grips swing, the clips located in the lower part of the housing with the possibility of radial rotation relative to it and rigidly connected with it in the axial direction, A groove of a rectangular profile and a recess are made on the inner surface of the cage, and rectangular flanges are made in the form of sectors on the outer surface of the casing, diametrically opposite guide pins are mounted rigidly on the inside of the cage with an interference fit perpendicular to the axis of the device.

The disadvantages of this device are:

- firstly, the shock-absorbing element is made of rubber, which in an aggressive environment during long-term operation of the electric centrifugal pump can lead to the loss of shock-absorbing properties;

- secondly, low reliability, due to the fact that the absence of a chamber for trapping sludge and cable clamps of the electric centrifugal pump leads to the fact that all the sludge and the clips removed from the cable fall on the anchor assembly, which can lead to jamming of the device in the well during failure in order to extract it from the well. In addition, the presence of a shear element in the design of the device from the destruction of which depends on whether the device will work or not, i.e. in the event of a pipe string breakage, the device may end up on the bottom of the well together with an electric centrifugal pump and cable, as well as a locking device that can jam in the well and as a result the anchor unit will not work.

The objective of the invention is to increase the reliability due to the guaranteed operation of the anchoring unit and eliminating jamming of the device when the device is removed in order to remove it, as well as the absence of shear elements and locking devices in the device design with the possibility of long-term operation of the shock-absorbing element in an aggressive environment with a rated load.

The problem is solved by an anti-flight device for an electric centrifugal pump, comprising an upper and lower sub, a barrel with a support ring rigidly mounted in its upper part, located on the barrel with the possibility of interaction between the shock-absorbing assembly with the cone and the anchor mechanism, and a shaped groove is made on the barrel below the cone having axial short and long sections in which the guide pin is located.

What is new is that the cone is made in the form of an external two-stage annular selection, and the anchoring mechanism is made in the form of a spring-loaded collet with a guide pin placed movably on the outer surface of the barrel opposite the figured groove, while the longitudinal short and long sections of the figured groove are interconnected by a closed shaped section so that when the axial reciprocating movement of the collet relative to the barrel, the guide pin will be located then in the longitudinal short section of the shaped pa a - transport position, in which the collet interacts on the one hand with the lower end of the lower stage of the outer stepped annular sampling of the cone, and on the other hand with the inner walls of the production string, then the working position is in the longitudinal long section of the figured groove, while the collet is on one side interacts with the lower end of the upper stage of the outer stepped annular sampling of the cone, and on the other with the groove of the production casing coupling, the shock-absorbing element being made in the form of a compression spring, and between the barrel m and the upper sub installed, muffled from the bottom of the sludge-catching chamber.

Figure 1 in longitudinal section presents anti-flying device for an electric centrifugal pump.

Figure 2 presents a scan of the shape and direction of the curly groove.

The anti-flight device for an electric centrifugal pump comprises an upper 1 (see FIG. 1) and a lower 2 sub, a barrel 3. A support ring 4 is rigidly mounted on the barrel 3 in the upper part, and a shock absorbing assembly is placed below the support ring 4 on the barrel 3, made in the form of a compression spring 5 with a cone 6 and an anchoring mechanism 7. On the barrel 3 below the cone 6 there is a shaped groove 8 (see figures 1 and 2).

The cone 6 (see figure 1) is made in the form of an external two-stage 9 and 10 ring sampling.

The locking mechanism 7 is made in the form of a collet 11 spring-loaded outside with a guide pin 12. A collet 11 spring-loaded outside is movably mounted on the outer surface of the barrel 3, opposite the figured groove 8.

Longitudinal short 14 (see Figs. 1 and 2) and long 13 sections of the figured groove 8 are interconnected by a closed figured section 15 so that when the axial reciprocating movement of the collet 11 relative to the barrel 3, the guide pin 12 will be located then in the longitudinal short section 14 of the shaped groove 8 is a transport position in which the collet 11 interacts on the one side with the lower end of the lower stage with an outer step ring sample 9 of the cone 6, and on the other hand with the inner walls 16 of the production casing 17. Length - L longitudinal to The short section 14 of the figured groove 8 is equal to the doubled length of the maximum lifting of the tool, for example, L = 2 × 0.2 m = 0.4 m during tripping (lifting the pipe string when removing from the elevator = 0.2 m).

That guide pin 12 will be located in a long longitudinal section 13 of the figured groove 8 - the working position. Collet 11 on the one hand interacts with the lower end of the upper stage of the outer stepped annular sample 10 of the cone 6, and on the other with the groove 19 of the coupling 18 of the production casing 17.

Between the barrel 3 and the upper sub 1 there is a bottom slam-trapping chamber 20. The cone 6 is located in the outer annular groove 21 (see Fig. 1) of the barrel 3 and interacts with the lower end of the outer annular groove 21 of the table 3 by means of a step 22 made on the inner surface cone 6. The design dimensions of the compression spring 5: spring diameter, coil diameter, pitch, etc., are selected by calculation based on the outer diameter of the barrel 3 and the weight of the electric centrifugal pump, depending on its size, length and type orazmera pipe string on which the lowered electric centrifugal pump.

The device operates as follows.

Before starting work, the anti-flying device is in a vertical position (see Figs. 1 and 2), while the guide pin 12 (see Fig. 2) should be in the upper part of the longitudinal short section 14 of the figured groove 8, while the anchor mechanism 7, made in the form of a spring-loaded collet 11 (see figure 1), is in the transport position and must be held in this position manually until the device enters the production casing when the tool is lowered.

The anti-flight device is installed directly under the electric centrifugal pump (ESP) and descends with it into the well on the tubing string (tubing) (Figs. 1 and 2). During the descent of the device as part of a pipe string with ESP into the production casing 17 of the well, the spring-loaded collet 11 is in the transport position (see Fig. 1), i.e. on the one hand, it interacts with the lower end of the lower stage of the outer stepped annular selection 9 of the cone 6, and on the other, with the inner walls 16 of the production casing 17, while the guide pin 12 is located in a longitudinal short section 14 of the figured groove 8.

10-15 meters before the landing interval of the device, the tubing string descent is stopped and a geophysical survey is carried out to determine the location of the closest coupling 18 of the production string 17, for example, using the coupling locator. Having decided on the placement interval of the coupling 18 in the production casing 1, the tubing string with the ESP and the proposed device is pulled in such a way that the anchoring unit 7, made in the form of a spring-loaded outside of the collet, enters the groove 19 of the production casing 18. Next, the anti-flying device is transferred from the transport position to the working one, i.e. the device is planted in a predetermined interval of the production casing 17 of the well.

To do this, from the mouth (not shown in FIGS. 1 and 2), the wells raise the tubing string by about 1 meter and lower, as a result of the operation, the guide pin 12 (see FIG. 2) moves from the top of the longitudinal short section 14 its lower part and then through the closed figured section 15 to the lower part of the axial long section 13 of the figured groove 8, and then with the subsequent lowering of the tubing string, the guide pin 12 moves from the bottom of the longitudinal long section 13 of the figured groove 8 to its upper part. Moreover, all the parts of the device, with the exception of parts 11 and 12 (see Fig. 1), which remain stationary due to the contact of the outer surface of the collet 11, spring-loaded outward with the inner walls of the production casing 17 of the well, are moved upward relative to the parts 11 and 12, and then down.

After getting the guide pin 12 (see Figs. 1 and 2) into the upper part of the longitudinal long section 13 of the figured groove 8, the device takes up a working position, while the collet 11 interacts with the lower end face of the upper stage of the outer step ring selection 10 of the cone 6, and on the other, with a groove 19 of the coupling 18 of the production casing 17.

During the operation of the ESP, detachment of the clamps securing the electrical cable to the pipe string, as well as sludge settling, are possible. For these purposes, a sludge-catching chamber 20 is provided (see FIG. 1), plugged from below, which traps sludge and klyams, which are subsequently removed with the device. As sludge traps 20, for example, one tubing with a diameter of 89 mm can be used.

In the event of a break in the tubing string from the ESP to the proposed device, a shock-absorbing unit is activated in the form of a spring 5, due to the fact that the cone 6 is located in the outer annular groove 21 (see Fig. 1) of the barrel 3 and interacts with the lower end of the outer annular the groove 21 of the table 3 by means of a ledge 22, made on the inner surface of the cone 6, the damping force of the drop of the ESP to the device is extinguished, while damage to the ESP is excluded.

The cone 6, the lower end face of the upper stage of the outer stepped annular selection 10 compresses the teeth of the spring-loaded outside collet 11 to the groove 19 of the coupling 18 of the production string 17 to the inner walls of the casing, and the barrel 3 first moves when the spring 5 is compressed downward relative to the cone 6, with the return spring 5 barrel 3 returns to its original position relative to the cone 6.

If necessary, for example, in the event of a break in the pipe string with ESP, the proposed device is removed along with the dangling pipe string and ESP.

For this, a catcher is lowered into the well by pipes (not shown in FIGS. 1 and 2) of any known structure, for example, with an internal grip. Having reached the interval of breakage of the tubing string, the catcher falls inside the upper pipe (not shown in Figs. 1 and 2), where it is fixed on its inner surface.

Then, from the wellhead, through the pipe string, the entire assembly is lifted up by about 1 meter and lowered, while the guide pin 12 first moves relative to the upwardly moving barrel 1 from the top of the longitudinal long section 13 of the figured groove 8 (see Fig. 2) closed curly section 15, and then during the descent moves from the closed curved section 15 to the upper part of the longitudinal short section 14 of the curly groove 8, moving the device from the working position to transport. Moreover, all the parts of the device with the exception of parts 11 and 12 (see Figs. 1 and 2), which remain stationary due to the contact of the outer surface of the tooth of the collet 11 with the groove 19 of the coupling 18 of the production casing 17, are first moved upward relative to the parts 11 and 12, and then down, while the collet 11 occupies a transport position in which it interacts on the one hand with the lower end of the lower stage of the outer step ring sample 9 of the cone 6, and on the other hand with the inner walls 16 of the production casing 17. After that, the device those with a broken string of pipes and ESP is removed to the surface.

The proposed anti-flying device for an electric centrifugal pump can improve the reliability due to the lack of shear elements in the design of the device. In addition, the design of the proposed device eliminates its jamming when the device is disengaged from the landing interval before being removed, since a slurry clams are installed above the anchor assembly for collecting sludge and breakaways detached from the cable, which avoids clogging of the anchor assembly, and the shock absorber is designed as a compression spring Allows the device to operate continuously in an aggressive environment with a design load.

Claims (1)

Anti-flying device for electric centrifugal. a pump containing upper and lower sub, a barrel with a support ring rigidly mounted in its upper part, a shock absorbing assembly with a cone and an anchor mechanism located on the barrel with the possibility of interaction, and on the barrel below the cone a shaped groove having axial short and long sections is made, which has a guide pin, characterized in that the cone is made in the form of an external two-stage annular selection, and the anchoring mechanism is made in the form of a spring-loaded collet with a guide pin, positioned movably on the outer surface of the barrel opposite the figured groove, while the longitudinal short and long sections of the figured groove are interconnected by a closed figured section so that with axial reciprocating movement of the collet relative to the barrel, the guide pin will be located in the longitudinal short section of the figured groove - transport the position in which the collet on the one hand interacts with the lower end of the lower stage of the outer stepped annular sampling of the cone, and on the other with the inner walls casing of the production casing, then in the longitudinal long section of the figured groove - the working position, while the collet on one side interacts with the lower end of the upper stage of the outer stepped annular selection of the cone, and on the other with the groove of the casing coupling, and the shock-absorbing element is made in the form of a spring compression, and between the trunk and the upper sub installed a muffled bottom sludge collecting chamber.

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