RU2534268C2 - Unit for alignment of pump sucker rods - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to machine building and can be used in production wells for alignment of pump sucker-rod pumps. Proposed unit comprises upper centraliser and coupling secured on one side to said upper centraliser. On coupling opposite side, lower centraliser, similar to upper one, is secured. Note here that ribs of flexed plates are fitted in upper and lower centraliser threaded fasteners, OD of said ribs being larger than ID of oil-well tubing. Lock nuts are fitted on the ends of said threaded fasteners. Application of plates in the design of proposed alignment unit allows locking of centralisers in oil-well tubing and concentric arrangement of pump sucker rods in oil-well tubing.

EFFECT: higher reliability of equipment, reliable locking of centraliser in oil-well tuning.

1 dwg

Description

The invention relates to the field of mechanical engineering and can be used in production wells for centering a string of pump rods (hereinafter referred to as KNSh) during rotation in tubing (hereinafter referred to as tubing), relieving axial forces of a KNSh and is applicable to the installation of a rod pump with a ground drive.

It is known to install a rod guide device in an oil field comprising a housing including connecting first and second housing elements, the first housing element having an external wear surface, at least one external conical surface located radially inside from the external wear surface and tapering radially along axial direction, the inner surface of the engaging rod and located radially inside from the outer conical surface to capture the outer surface ty rod, the loaded shoulder of the first housing element located radially outside the outer wear surface, the second housing element has an external wear surface, an inner conical engaging surface located radially inside from the outer wear surface, for axial sliding engagement with at least one outer conical the surface of the first housing element, for moving at least part of the housing radially inward towards the position of the gripping rod around the rod, the inner the rod engagement extending radially inside from the inner conical engaging surface for gripping the outer surface of the rod, the loaded shoulder of the second housing element, located radially outside the external wear surface at an axial distance from the loaded shoulder of the first housing element, and a sleeve located around the first and second housing elements in a gripping position between the loaded shoulders of the first and second housing elements and having an internal wear surface for yaschego contact with the outer surfaces of the wear of the first and second housing elements and an outer wear surface for contact with the inner surface of the tubular oil conduit (see. patent for invention RU No. 2374423, publ. 11/27/09, IPC Е21В 17/10).

The disadvantages of this device are the impossibility of removing the axial load, low efficiency and low reliability in highly curved and horizontal wells, where it is difficult to install a string of pump rods in the center of the tubing, which results in impacts and abrasion of the rods on the tubing and increases the number of breaks and KNSh lapels. The disadvantages include low maintainability, the inability to assess the condition of the rod inside the device when diagnosing the rod.

Known centralizer spring non-separable, containing rings connected by spring arcuate strips mounted on the outer surface of the rings (see patent for utility model RU No. 20923, publ. 10.12.2001, IPC ЕВВ 17/10).

The disadvantage of this centralizer is the inability to use as a centering device to install a rod pump with a ground drive, because the design does not include a bearing assembly.

Known centralizer for sucker rods, comprising a housing with a centering element, the housing is made in the form of a cylindrical rod with an annular protrusion and connecting threaded threads at the end sections, and its centering element is made in the form of a rolling bearing, with an interference fit on the housing to the annular protrusion and is equipped with sealing lids fixed to each other by fastening threaded parts, while the sealing covers are made with longitudinal cutouts or with through longitudinal holes for the passage of the reservoir fluid, the o-ring installed between the sealing caps, is made with longitudinal cutouts or with through longitudinal holes (hereinafter referred to as the centralizer) (see RF patent for utility model No. 84,442, class E21B 17/10, published 06.02.2009 g.). The specified centralizer in technical essence is closer to the proposed unit for centering the sucker rods, and it can be taken as a prototype.

The disadvantages of this centralizer are the ability to rotate the centralizer in the tubing with a small angle of inclination of the well and the presence of a technological gap between the centralizer and tubing, which does not allow to install the string of pump rods coaxially and directly in the center with respect to the inner wall of the tubing pipes.

The technical result of the claimed invention is the creation of a design that allows you to center the rotational column coaxially with the inner wall of the tubing, increasing the reliability of the equipment, eliminating the possibility of turning the centralizer in the tubing.

The technical result is solved by the described centering unit of the sucker rods containing the upper centralizer, secured by a lower connecting thread with a coupling.

What is new is that, on the other side of the coupling, a lower centralizer, similar to the upper centralizer, is fastened with an upper connecting thread, moreover, ribs of specially curved bars are inserted into the fastening threaded parts of the upper and lower centralizers, the outer diameter of which is larger than the inner diameter of the tubing, and at the ends fastening threaded parts mounted lock nuts.

The use of slats in the design of the proposed centering unit for sucker rods will prevent centralizers from turning in the tubing, provide a concentric placement of the KNSH in the tubing and prevent the KNS from adhering to the walls of the tubing.

The invention is illustrated by drawings, where:

- figure 1 shows the block alignment unit of the sucker rods in section, front view;

- figure 2 is a working arrangement of the centering unit of the sucker rods of figure 1 in the tubing, bottom view.

The centering unit of the sucker rods (Fig. 1) contains a centering element in the form of a rolling bearing, namely a rotating inner ring 1, a fixed outer ring 2 and rolling bodies 3 placed between them. The rotating inner ring 1 is fitted with an interference fit on the housing 4, made in in the form of a cylindrical rod, to the annular protrusion 5, which serves to prevent axial displacement of the rotating inner ring 1 relative to the housing 4. As a protection of the rolling elements 3 from the pumped medium, sealing devices о, consisting of sealing covers 6 and 7, tightened together by a fastening threaded part 8. To seal the gaps between the sealing covers 6 and 7 and the stationary outer ring 2, a radial seal is used - the sealing ring 9. For the passage of liquid, the sealing covers 6 and 7 are made with longitudinal protrusions 10. The sealing covers 6 and 7 have grease annular grooves 11 and 12. Parts at positions 1 to 12 form the upper centralizer I and is shown in FIG. 1 by a dashed line. Details at positions 16 through 28 form the lower centralizer II, shown in FIG. 1 by a dashed line. The body 4 of the upper connecting threaded thread 13 at the end section is connected to the KNSH coupling (not shown in the figures), and the lower connecting threaded thread 14 is connected to the lower centralizer II through the coupling 15. The lower centralizer II is connected to the coupling 15 of the upper connecting threaded 16. The lower centralizer II is similar to upper centralizer I and consists of the same parts, namely: a rotating inner ring 17, a fixed outer ring 18, rolling elements 19, a housing 20 with an annular protrusion 21, sealing caps 22 and 23, interconnected by a fastening threaded part 24 and made with longitudinal protrusions 25 and fat ring grooves 26 and 27, the sealing ring 28. The number of longitudinal protrusions 10 and 25 is at least two.

To exclude the rotation of the upper I and lower II centralizers relative to the tubing, when operating in the well, specially curved slats 31 are inserted into the fastening threaded parts 8 and 24 by ribs 29 and 30. To prevent the outgoing from the fastening threaded parts 8 and 24 of the ribs 29 and 30, stop (self-locking) nuts 32 and 33. The outer diameter of the slats 31 is larger than the inner diameter of the tubing 34 (FIG. 2). The number of slats 31 corresponds to the number of longitudinal protrusions 10 and 25.

To facilitate the analysis of the centering unit of the sucker rods on the bodies 4 and 20, flats 35 and 36 are provided.

The housing 20 of the lower centralizer II lower connecting threaded thread 37 is connected to the KNSH (not shown in the figures).

The centering unit of the sucker rods operates as follows.

The centering unit of the sucker rods is lowered into the tubing 34 as KNSh elements (not shown in the figures), when passing through the different diameters of the tubing 34, due to their wall thickness, the straps 31 are deformed, move in the radial direction and together with the KNSh passes on. When the diameter of the pipes increases, the planks return to their original position. When the strips 31 are deformed, the ribs 29 and 30 move along the fastening threaded parts 8 and 24.

When the rotation of the KNS rotates the housings 4 and 20, the rotating inner rings 1 and 17, and the stationary outer rings 2 and 18, the sealing caps 6, 7, 22 and 23, as well as the straps 31 remain stationary. The production of the wellbore is lifted by a helical sucker rod pump (not shown in the figures) along the longitudinal protrusions 10 and 25, and then along the annular gap between the tubing and KNSh to the fluid transfer line.

Thanks to the proposed technical solution, contact between the KNSh and the tubing wall is excluded, since the centering unit of the sucker rods remains stationary relative to the tubing during rotation of the KNSH, and the sucker rods will be located almost in the center of the tubing, which eliminates the wear of the rods and tubing. The unit for centering the sucker rods also reduces the friction moment, reduces the constant axial load, reduces the torque in the string of sucker rods, makes it possible to use the rotation of the string of sucker rods not only in curved, deviated, but also in horizontal wells. The invention is distinguished by the simplicity of installation, maintenance during dismantling, as well as low cost due to a simple structure.

Thanks to the use of the centering unit of the sucker rods, the necessary alignment of the KNSH with respect to the tubing is achieved.

Claims (1)

A sucker rod centering unit comprising an upper centralizer fixed by a lower connecting thread with a coupling, characterized in that on the other side of the coupling, a lower centralizer, similar to the upper centralizer, is secured by a upper connecting thread and the specially designed curved threaded parts of the upper and lower centralizers are inserted strips, the outer diameter of which is larger than the inner diameter of the tubing, and a stopper is installed at the ends of the threaded fasteners s nuts.

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