RU2668891C2 - Antilock device for electrocentropic pump - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: device contains the upper and lower subs, casing, consisting of anchoring and damping barrel sites, located in the central part, has conical and cylindrical parts. In this case, in the lower part of the body inside the longitudinal grooves, there are biscuits, which are able to deviate from the axis of the body due to axial movement along the conical part of the barrel. In addition, the cushioning assembly consists of a spring centralizer, whose flat springs are made of metal with shape memory effect.

EFFECT: increasing the reliability of the device and simplifying the design.

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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 (USSR author's certificate 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 installed at the wellhead with the possibility of interacting with a string of lifting pipes with a spring generator installed under an electric submersible pump with the possibility of interacting with a pair of casing pipes of an additionally spring-loaded additional rollers having at least one electric current generator, the anchor assembly 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, the movable ram grip wedges pivotally connected by means of strips to the rod, and the generators of the main and additional rollers are electrically interconnected by means of an electric submersible pump cable and a cable collector about the drum.

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.

A device is also known for preventing the fall of underground equipment at the bottom of a well, for example, a submersible electric pump (USSR author's certificate 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 capable of interaction, 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 CNAM, 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) containing the upper and lower sub, the barrel with a support ring mounted in its upper part, located on the barrel with the possibility of interaction between the shock-absorbing unit and the cone and the anchoring mechanism, while on the trunk 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 long section is made from the bottom part of the cone to the lower sub, the length of the short section is equal to 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 anchoring mechanism, in addition, in the curly groove when the transition section enters the long a 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 anchoring mechanism consists of a housing located married on the barrel with the possibility of axial movement, installed uniformly around the circumference of the body and spring-loaded double-acting 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 grips and which is the axis relative to which they swing captures, 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, moreover, on the inner surface the clips have a groove of a rectangular profile and a recess above it, and on the outer surface of the housing in the form of sectors, the shoulders of a rectangular profile are made, in the inner part of the holder there are mounted diametrically opposite guide pins rigidly tightened 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 prolonged operation of the electric centrifugal pump can lead to a 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, 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 disadvantage of this device is the design complexity and lack of reliability.

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.

In FIG. 1 shows in longitudinal section an anti-flying device for an electric centrifugal pump.

The anti-flight device for an electric centrifugal pump contains the upper 1 (see Fig. 1) and the lower 2 sub, barrel 3. On the barrel 3 in the upper part there is a movable housing 4 with anchor 5 and shock-absorbing (centering) 6 nodes, including longitudinal grooves 7, crackers 8, having the possibility of rotation on the axes 9, a cone 10 is made on the lower part of the barrel 3 with the possibility of interaction between the shock-absorbing mechanism 6 and the anchor mechanism 7. The spring springs 11 of the shock-absorbing mechanism 6 are made of metal with a shape memory effect having of high corrosion and erosion resistance.

The device operates as follows.

Before starting work, the anti-flight device is in a vertical position, while the housing 4 should be in the lower part of the barrel 3 until it stops, while the anchor mechanism 5 is in the transport position and the crackers 8 are as far removed as possible from the inner surface of the casing (transport position).

The anti-flight device is installed directly below the electric centrifugal pump (ESP) and descends with it into the well on the string of tubing (tubing). After the installation is turned on and the case elements of the PED and, respectively, the lifted fluid are heated, springs made of a material with a shape memory effect return the geometry to its original position, providing reliable mechanical contact with the casing at the installation site and creating conditions for instant anchoring during flight »Installation.

In the event of a breakdown of the tubing string with an ESP or disintegration of fragments of the downhole pumping equipment, for example, a gas separator, the cone 11 of the lower part of the barrel 3 presses crackers 8 to the casing, providing damping of the unit’s fall force and its braking, thus preventing damage to the ESP.

After restoring the temperature regime in the well (cable breakage, shutting down the SEM) and changing the geometry of the springs 11 made of metal with the shape memory effect, fishing and recovery work is performed in the well.

For this, a catcher is lowered into the well using pipes (not shown) of any known construction, for example, with an internal grip. Having reached the interval of breakage of the tubing string, the catcher falls into the upper pipe (not shown), where it is fixed on its inner surface.

The proposed anti-flying device for an electric centrifugal pump allows to increase the reliability of operation and use of materials having high corrosion and erosion resistance, to work for a long time in an aggressive environment with a rated load.

Claims (1)

An anti-flight device for an electric centrifugal pump containing the upper and lower sub, a housing consisting of anchor and shock absorbing assemblies, a barrel located in its central part having a conical and cylindrical part, characterized in that crackers are installed in the lower part of the housing inside its longitudinal grooves which have the ability to deviate from the axis of the body due to axial movement along the conical part of the barrel, and the shock-absorbing unit consists of a spring centralizer, flat springs which made of a metal with shape memory.

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