RU84442U1 - PUMP ROD CENTER - Google Patents

Abstract

A centralizer for sucker rods comprising a housing with a centering element, characterized in that the housing is made in the form of a cylindrical rod with an annular protrusion and threaded connecting 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 caps fixed to each other by fastening threaded parts, while the sealing covers are made with longitudinal cutouts or with through longitudinal ERSTU for the passage of formation fluid, wherein a sealing ring located between the sealing lids made with longitudinal recesses or longitudinal to the through holes.

Description

The utility model relates to the field of engineering and can be used in production wells for centering the string of pump rods during rotation in tubing (hereinafter - tubing), relieving the efforts of the string of pump rods (hereinafter - KNSh) and is applicable to the installation of a screw rod pump with a ground driven.

The well-known centralizer of the rods of the company "KUDU", installed between the rod nipples and consisting of three parts: spindle, sleeve and rod nipple (Catalog of screw pumps of the company "KUDU" for oil wells, p.48, 49).

Known inter-coupling centralizers (analogue), made according to the technology of the Enterra company from glass-filled polyamide, as well as centralizers mounted on a sucker rod (Catalog of Motovilikhinsky Plants, p.40-41).

The disadvantages of these centralizers 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 above centralizers cannot perform the functions of a bearing, namely, to reduce the loads on the ground drive and the pump rod string, to reduce the friction moment and the torque in the KNS. In addition, the manufacturing process of these centralizers is laborious. The disadvantages include low maintainability, the inability to assess the condition of the rod inside the device when diagnosing the rod. Non-metallic centralizers can be destroyed if the permissible contact pressure of the centralizer with the inner tubing wall is exceeded.

Pieces of the destroyed centralizer disrupt the operation of the pump, wear of the tubing and oil pumping system occurs, which makes unplanned well repair necessary.

Known special guiding couplings AzNIIDN, polyamide and gummed tread couplings (Reference book on oil production. Edited by Dr. of technical sciences Sh.K. Gimatudinova. M., "Nedra". 1974, p.348).

Known devices for reducing the attrition of tubing and rods, including a non-metallic casing with a longitudinal cut of a profile shape and a connecting element with a mating surface equipped with traverses with two longitudinal and two transverse holes located on the ends of the casing and connecting threaded elements installed in them (A S. USSR No. 1493765, class E21B 17/10, publ. 07.15.1989 g). The specified device by technical nature is closer to the proposed centralizer for sucker rods, and it can be taken as a prototype.

The disadvantages of these centering devices are the impossibility of using sucker rods when rotating the column, since there is a lot of wear during friction in the tubing.

The technical task of the claimed utility model is to eliminate the wear of the rods / tubing, reducing the friction moment, reducing the constant load, the possibility of using the rotation of the string of pump rods not only in curved, deviated, but also in horizontal wells, reducing the complexity and cost of manufacturing the device.

The stated technical problem is solved by the described centralizer for sucker rods (hereinafter referred to as the centralizer), comprising a housing with a centering element.

What is new is that the casing 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 casing to the annular protrusion and is equipped with sealing covers fixed to each other by threaded fasteners parts, wherein the sealing caps are made with longitudinal cutouts or with through longitudinal holes for the passage of formation fluid, the sealing ring, Installed between the sealing covers, it is made with longitudinal cutouts or with through longitudinal holes.

The proposed utility model is illustrated by drawings, where:

- figure 1 shows the centralizer in the context, front view;

- figure 2 - the centralizer of figure 1, made with through longitudinal holes, bottom view;

- figure 3 - the centralizer of figure 1, made with longitudinal cuts, bottom view;

- figure 4 is a centralizer with a non-metallic clip in the context, front view;

- figure 5 is a centralizer with an enlarged fixed outer ring in a section, front view;

- figure 6 is a centralizer, a variant with a gap seal in the context, front view;

- Fig.7 - the centralizer of Fig.6, made with through longitudinal holes, bottom view;

- in Fig.8 - the centralizer of Fig.6, made with longitudinal cuts, bottom view;

- figure 9 is a sealing ring with through longitudinal holes, bottom view;

- figure 10 is a sealing ring with longitudinal cuts, bottom view;

- figure 11 is a non-metallic clip to figure 4 with through longitudinal holes, bottom view;

- figure 12 is a non-metal clip to figure 4 with longitudinal cuts, bottom view;

- Fig.13 is an enlarged fixed outer ring to Fig.5 with through longitudinal holes, bottom view;

- Fig.14 is an enlarged fixed outer ring to Fig.5 with longitudinal cuts, bottom view;

- in Fig.15 - the operating position of the centralizer in the tubing;

- in Fig.16 - a well equipped with a sucker rod pump with a ground drive.

The centralizer (figures 1, 4, 5, 6) contains a centering element in the form of a rolling bearing, namely a rotating inner ring 7, a fixed outer ring 2 and rolling bodies 3 placed between them. The rotating inner ring 1 is tightened onto the housing 4 made in the form of a cylindrical rod to the annular protrusion 5, which serves to prevent axial displacement of the rotating inner ring 7 relative to the housing 4. When designing the centralizer, the angle of curvature of the well should be taken into account (to select a reliable sealing th device) and the direction of action of the perceived load (the bearing is selected from the following types: radial, thrust, radial thrust, thrust radial). It is also necessary to choose the desired shape of the rolling body (ball or roller); the number of rows of rolling bodies (single, double, four and multi-row); a design feature group (with a cylindrical or conical bore of a rotating inner ring; single or double; double, triple, quad, etc.), etc. As a protection of rolling elements 3 from the pumped medium, a sealing device consisting of sealing covers 6 and 7 (Figs. 1-5), tightened together by a fastening threaded part 8. To seal the gaps between the sealing caps 6 and 7 and the stationary outer ring 2, a radial seal — the sealing ring 9 — serves as an internal cavity 10 not lubricated to prevent metal-metal contact between the rolling bodies 3 by creating an oil film between them. The lubricant also serves to remove heat from the rolling elements 3 and to reduce friction in them, thereby improving their characteristics. The housing 4 with connecting threaded threads at the end sections is connected to the column of sucker rods 11 (Fig. 15} by a sleeve 12. Between tubing 13 (Fig. 15) and KNSh 11 there are ring gaps 14 and 15. To hold the rolling elements 3 from each other a certain distance and ensure uniform load distribution is a separator (not shown in the figures), having cells according to the size of the rolling body 3. For the passage of fluid in a stationary outer ring 2 (Fig.13) and sealing caps 6 and 7 (Fig.2) can be through longitudinal holes are made i 16. In figures 1, 4 and 5, the sealing caps 6 and 7 are made with fatty annular grooves 18 and 19, which are filled with a thick lubricant that creates the necessary seal. Other types of seals can be used as seals, for example, radial, lip seals, gland seals, etc. The number of centralizers in the string of pump rods 11 depends on operating conditions (curvature of the wellbore).

It is also possible to use a non-metallic ferrule 20 (FIG. 4), which is connected to the stationary outer ring 2 inseparably (for example, by injection molding, thermal pressing, etc.) and has a rigid frictional adhesion to the surface of the stationary outer ring 2. Using a set of molds, it is possible to provide molding of this type of centralizer for any diameter of tubing 13 and the diameter of the stationary outer ring 2 associated with a specific diameter of the tubing 13.

A variant with a fixed outer ring 2 (Fig. 5) made of an increased diameter is also possible.

It is also possible that the centralizer uses protective seals 21 and sealing caps 22 and 23 made with slotted seals 24 and 25 (Figs. 6-8). The sealing caps 22 and 23 prevent the ingress of mechanical impurities to the protective seals 27 and reduce the pressure of the well production on the rolling body 3.

Sealing covers 6, 7, 22 and 23 can be made both metal and non-metal. The sides of the sealing caps 6, 7, 22 and 23 may be rounded or chamfered. The rounding (chamfer) helps to improve the movement of the centralizer during tripping. On the outer surface of the fixed outer ring 2 (Fig. 14), sealing caps 6 and 7 (Fig. 3), O-ring 9 (Fig. 10), non-metallic cage 20 (Fig. 12), sealing caps 22 and 23 (Fig. 8) longitudinal cuts are made 17. The sealing ring 9 (Fig. 9), non-metallic ferrule 20 (Fig. 11), sealing caps 22 and 23 (Fig. 7) can be made with through longitudinal holes 16.

The outer diameter of the centralizer (Fig. 15) is smaller than the inner diameter of the tubing 13. This condition is necessary to create a technological gap 26 between the tubing 13 and the centralizer in order to avoid jamming of the KNSh 11 during hoisting operations.

The well equipped with the installation of a rod screw pump with a ground drive (Fig), contains a reservoir 27, a casing 28 with perforations 29, a screw rod pump 30 with a string of pump rods 77, tubing 13, a drive head 31 with an engine 32 , wellhead 33 and a fluid transfer line 34.

The centralizer works as follows.

When you turn on the engine 32 (Fig.16) of the drive head 31 rotates a polished rod (not indicated in Fig.16), KNSH 77, the housing 4 (Fig.1, 4-6) and the rotating inner ring 7, and the stationary outer ring 2 remains motionless. The production of the reservoir 27 (Fig.] 6) through the perforation holes 29 is lifted by a screw rod pump 30 along the annular gap 14 (Fig.15) between the tubing 13 and KNSh 77 through the through longitudinal holes 16 (Fig.2 and 7) or longitudinal cutouts 17 ( 3 and 8), along the technological gap 26 (FIG. 15) and further along the annular gap 15 to the liquid transfer line 34 (FIG. 16). The variable loads of the KNSh 11 are due to the presence of a falling characteristic of the coefficient of friction from the speed of the rubbing surfaces in the screw rod pump 30, which leads to a sudden breakdown of the KNSh 11, i.e. failure of the pumping unit and the need for underground repairs to eliminate the KNSh 11 breakage. Therefore, the functions of the rolling bearing in the centralizer allow you to solve a lot of problems during the operation of the well with a screw rod pump.

Thanks to the proposed technical solution, contact between the KNSh and the tubing wall is excluded, since the centralizer 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 centralizer also reduces the friction moment, reduces the constant load, reduces the torque in the string of pump rods, makes it possible to use the rotation of the string of pump rods not only in curved, deviated, but also in horizontal wells. In addition, the advantages of a centralizer are a small amplitude of fluctuation of resistance to rotation during operation of a string of pump rods, the requirement of interchangeability and unification of elements of centralizer nodes is satisfied, and the requirement of transportation and storage is satisfied. The utility model is distinguished by ease of installation, maintenance during dismantling, as well as low cost due to a simple structure. The centralizer provides reduced power consumption. In addition, the use of the inventive device will allow to exclude the nomenclature "Pumping rod with centralizers CVN" and to operate wells only "rods without centralizers."

Claims (1)

A centralizer for sucker rods comprising a housing with a centering element, characterized in that the housing is made in the form of a cylindrical rod with an annular protrusion and threaded connecting 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 covers fixed to each other by fastening threaded parts, while the sealing covers are made with longitudinal cutouts or with through longitudinal ERSTU for the passage of formation fluid, wherein a sealing ring located between the sealing lids made with longitudinal recesses or longitudinal to the through holes.