Improved polished rod rotator

Abstract

An improved apparatus and methods of use for rotating a reciprocating rod string used in artificial lift pumping equipment is provided, the apparatus having a modified worm wheel for receiving a mechanical interlock formed between the worm wheel at the rod clamps secured to, and operative to rotate, the rod string.

Description

Improved Polished Rod RotatorCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 571 ,882 filed March 29, 2024, entitled “Improved Polished Rod Rotator”, which is specifically incorporated by reference herein for all that it discloses or teaches.FIELD

[0002] Embodiments herein are generally related to the field of oil wells and wellhead equipment, and more particularly to oil wells where extraction is carried out using artificial lift pumping equipment with a reciprocating rod string, referred to as sucker-rods.BACKGROUND

[0003] Artificial lift pumping equipment is commonly used in the oil and gas industry to enhance the flow of hydrocarbons from a well when natural reservoir pressure is insufficient to bring them to surface. Mechanical lift systems, such as bottom-hole pumps (or ‘sucker rod’ pumps), operate using a reciprocal motion driven by a surface pump jack to actuate a string of sucker rods, which in turn drives the downhole pump. The string of sucker rods is formed from a series of steel rods; the uppermost rod being known as the ‘polished’ rod or ‘polish’ rod, which serves as the interface between the surface pumping unit and the sucker rod string. To accomplish the pumping action from the well, reciprocating motion is provided to the sucker rod string by suspending the polish rod from a rocking beam by means of a suitable hanger.

[0004] Many oil wells have deviations from the vertical axis resulting in uneven wear on the sucker rod string as it reciprocates in and out of the well. If the rod string is not properly centralized, excessive rubbing against the tubing can lead to localized wear and even failure. For instance, in deviated wells, the rod string is bent at angles, causing localized rubbing and wear, while sharp doglegs create high-stress points.

[0005] One technique used to reduce uneven wear on the sucker rod string is to periodically rotate the rod string within the wellbore (usually clockwise) using a rod rotator device. This process aims to distribute wear more evenly around the rods and tubing. While rod rotators can be useful in reducing wear and extending the life of the sucker rod, known rotators suffer from several setbacks, particularly where the rotator is incorrectly sized or poorly installed, where high torsional drag leads to rod twisting, sticking, or breakage, or where to rotator itself fails due to wear, corrosion, or excessive force. Some rotators rely on frictional engagement between the rotator and the rod clamps to ensure proper rotation of the rod string, where the rotator frictional ly ‘grips’ the clamps in order to rotate the entire rod string.

[0006] Attempts to improve the frictional engagement between rod rotators and rod clamps have been made. Some rotators use serrated grips or high friction contact surfaces. Others, such as the system described in U.S. Patent No. 11 ,268,331 , use a nested top cap on the rotator for receiving the clamps. Such known rotator systems, however, comprise complicated mechanics and are difficult to maintain or replace when needed. For instance, failure points typically occur to componentry internal to the rod rotator, such as the ratcheting mechanism or one-way bearing that is attached to the worm gear, and the shear pin that is inserted between the worm wheel and topcap. When internal componentry fails, the entire rod rotator must be removed from the pump jack hanger and either disassembled and repaired or abandoned and replaced with a new rod rotator. Traditional rod rotators may also rely on the friction between the underside of the top cap and the top of the worm wheel to rotate the top cap, which serves to rotate the polished rod. These components are also internal to the rod rotator and are at increased risk of becoming contaminated with a layer of grease if the rotator is improperly lubricated during maintenance. It is well known that grease causes a significant reduction in the coefficient of friction between the top cap and the worm wheel, rendering the rod rotator less effective or even inoperable.

[0007] There remains a need for an improved rod rotator system operative to ensure engagement with the rod clamps, such system being modifiable depending upon the size of the rod clamps, while also being easily maintained and or repaired when needed.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Embodiments of the present disclosure will now be described, by way of example only, with reference to the attached Figures.

[0009] Figure 1 is a side elevation perspective view of an improved apparatus for rotating a string of sucker rods during the operation of artificial lift pumping equipment, according to embodiments;

[0010] Figure 2A is a side elevation cross-section view of a first embodiment of the apparatus shown in FIG. 1 , according to embodiments;

[0011] Figure 2B is a front cross-section view of the first embodiment of the apparatus shown in FIG. 2A, according to embodiments;

[0012] Figure 2C is a zoomed-in side elevation perspective view of the first embodiment of the apparatus shown in FIG. 2A, according to embodiments;

[0013] Figure 2D is a further front cross-section view of the first embodiment of the apparatus shown in FIG. 2A (with rod clamps removed), according to embodiments, FIGS. 2A - 2D collectively referred to as FIG. 2;

[0014] Figure 3A is a side elevation cross-section view of a second embodiment of the apparatus shown in FIG. 1 , according to embodiments;

[0015] Figure 3B is a front cross-section view of the second embodiment of the apparatus shown in FIG. 3A, according to embodiments;

[0016] Figure 3C is a zoomed-in side elevation perspective view of the second embodiment of the apparatus shown in FIG. 3A, according to embodiments, FIGS. 3A - 3C collectively referred to as FIG. 3;

[0017] Figure 4 is a perspective left side view of the apparatus shown in FIG.1 , according to embodiments;

[0018] Figure 5 is a perspective right side view of the apparatus shown in FIG.1 , according to embodiments;

[0019] Figure 6 is a side elevation perspective view of a shear pin of the presently improved apparatus, according to embodiments;

[0020] Figure 7A is a side cross section view of a first embodiment of the shear pin shown in FIG. 6, the pin shown having an annular groove of a first size, according to embodiments;

[0021] Figure 7B is a side cross section view of a second embodiment of the shear pin shown in FIG. 6, the pin shown having an annular groove of a second size, according to embodiments; and

[0022] Figure 7C is a side cross section view of a second embodiment of the shear pin shown in FIG. 6, the pin shown having an annular groove of a third size, according to embodiments, FIGS. 7A - 7C collectively referred to as FIG. 7.SUMMARY

[0023] According to embodiments, an apparatus for rotating a reciprocating rod string used in artificial lift pumping equipment is provided, the equipment having a lever arm operably connecting the equipment to the apparatus, the apparatus operably connected to a plurality of rod clamps secured to at least one rod of the rod, the apparatus comprising a tubular body having an uphole end, a downhole end, and a central bore for receiving the string of rods extending therethrough, a worm gear assembly, rotatably housed within the central bore of the body, the worm gear assembly having, a worm, the worm having an elongate shaft forming a plurality of helical worm threads about an outer surface, a worm wheel, the worm wheel having an uphole end, a downhole end, and forming a plurality of helical wheel threads about an outer surface, the wheel threads corresponding to and engaging with the worm threads, a central wheel bore, the wheel bore in concentric alignment with the central bore of the body, and configured to receive the rod string extending therethrough, wherein, at its uphole end, wheel forms a worm wheel extension portion extending uphole through and protruding from the central bore of the body, at least one releasable mechanical interlock between the worm wheel extension portion and atleast one of the rod clamps, wherein, actuation of the lever arm rotates the worm, the helical threads of the worm engaging the corresponding helical threads of the wheel, which then turns the rod clamps and the rod string.

[0024] In some embodiments, the at least one mechanical interlock may comprise a shearable interlock. In some embodiments, the shearable interlock may comprise at least one shear pin.

[0025] In some embodiments, the worm wheel extension portion may form a recess for receiving a downhole portion of at least one shear pin.

[0026] In some embodiments, the apparatus may further comprise at least one tubular bushing positioned within the central bore for receiving and centralizing the rod strings extending therethrough.

[0027] In some embodiments, the apparatus may further comprise at least one bearing assembly. In some embodiments, the apparatus may further comprise at least two bearing assemblies.

[0028] In some embodiments, the apparatus may comprise at least one wedge portion positioned between the worm gear assembly and the rod clamps. In some embodiments, the wedge portion may form at least one recess for receiving at least one uphole portion of a shear pin.

[0029] In some embodiments, the apparatus may further comprise at least one customized rod clamp having a bottom surface configured to correspondingly interface in alignment with a top surface of the apparatus.

[0030] According to embodiments, methods of rotating a string of sucker rods during the operation of artificial lift pumping of a subterranean wellbore are provided,the artificial pumping performed artificial pumping equipment having at least one rotator apparatus operably connected to a plurality of rod clamps secured to at least one rod of the rod string, the methods comprising providing a rotator apparatus operably connected to the plurality of rod clamps, the apparatus having a body forming a central bore for receiving the rod string extending therethrough, a worm gear assembly housed within the central bore of the body, the worm gear assembly having, a worm wheel rotatable by a worm shaft, the worm wheel forming a worm wheel extension portion extending uphole through and protruding from the central bore of the body, at least one releasable mechanical interlock positioned between the worm wheel extension portion and at least one of the rod clamps, actuating a lever arm operably connected to the rotator apparatus to rotate the worm, thereby rotating the worm wheel and the plurality of rod clamps, wherein the rotation of the worm wheel transmits rotation motion from the worm wheel extension to the plurality of rod clamps via a combination of frictional engagement and the releasable mechanical interlock.

[0031] In some embodiments, rotation of the worm gear occurs when helical threads formed on the worm shaft engage corresponding helical threads on the worm gear.

[0032] In some embodiments, the at least one releasable mechanical interlock may comprise a shear pin and the method further comprises shearing the shear pin when the torque applied to the rod string exceeds a predetermined torque threshold. In some embodiments, the predetermined threshold may be based upon the size of the rod string and the method further comprises selecting the shear pin to optimize the predetermined torque threshold.

[0033] In some embodiments, the at least one releasable mechanical interlock may operate as a controlled failure point at an interface between the worm wheel extension portion and at least one of the rod clamps.

[0034] In some embodiments, the method further comprises removing a wheel cap from the worm wheel extension to replace the releasable mechanical interlock.

[0035] In some embodiments, the apparatus provided may further comprise at least one wedge portion positioned between the worm wheel extension and the plurality of rod clamps.

[0036] In some embodiments, the worm wheel is rotatable within the central bore of the housing.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] According to embodiments, an improved rod rotating apparatus and methods of use are provided to periodically rotate a string of reciprocating sucker rods used in artificial lift pumping equipment in the oil and gas industry, where the apparatus and methods serve to mitigate loss of frictional engagement or ‘slips’ between the improved rod rotating apparatus and at least one rod clamp secured to the sucker rod string being rotated. In some embodiments, the presently improved rod rotating apparatus may be configured to provide a positive mechanical interlock directly between the worm gear assembly of the rotator apparatus and the rod clamps, increasing resistance to slippage between the rotator and the rod clamps. In some embodiments, the presently improved rod rotating apparatus and methods of use may provide increased load capacities imposed upon the rotating apparatus.

[0038] Herein, the term “uphole” is generally used to refer to a position or direction closer to the wellhead, and the term “downhole” is generally used to refer to a position or direction closer the wellbore.

[0039] Herein, the term “torque” is generally used to describe the moment of force applied to rotate a rod string about its axis. Torque is typically measured in footpounds (ft-lb) and represents how much force is applied at a given distance from the axis of rotation. For example, where the torque is too low, insufficient rotation of the rod string can lead to uneven wear and increased mechanical stress points, whereas, excessive torque can cause over-twisting of the rod string, potentially leading to fatigue, thread damage, or premature failure.

[0040] The presently improved apparatus and methods of use will now be described in more detail having regard to FIGS. 1 - 7.

[0041] According to embodiments, having regard to FIG. 1 , an improved apparatus 10 for rotating a string of sucker rods 2 is shown. In some embodiments, apparatus 10 may be installed on the wellhead above surface, generally above the stuffing box and the carrier bar and below the polished rod clamps 3, enabling apparatus 10 to rotate the sucker rod string 2 with each stroke of the pumping unit (e.g., reciprocating horsehead of the pump jack). As would be appreciated, sucker rod string 2 may be secured in position by, and rotatably coupled to, one or more rod clamps 3. Clamps 3 may be any clamps typically used in the industry (including clamps having clamp bolts, not shown).

[0042] In some embodiments, having regard to FIGS. 2 and 3, apparatus 10 may be configured to house a worm gear assembly 20, operably connected to aratchet mechanism (e.g., a ratchet arm) attached to the reciprocating horsehead of the pump jack. As will be described in more detail, apparatus 10 may house a worm gear assembly consisting of a worm (22, screw-like gear) that engages a worm wheel (24, larger gear that meshes with the worm to transmit power at a 90° angle), and a ratchet arm 14 operably connected to the reciprocating horsehead (14; FIG. 2B and 3B). In this manner, as would be understood, reciprocating (up and down) movement of the horsehead engages ratchet arm 14 (conventionally referred to as the ‘actuator’) to rotate worm 22, causing corresponding rotation of worm wheel 24 and ultimately rotation of rod string 2. As would be appreciated, worm wheel assembly 20 serves to translate the ratcheting motion of ratchet arm 14 into rotational motion of the string of sucker rod string 2.

[0043] In some embodiments, having regard to FIGS. 2B and 3B, apparatus 10 may comprise a tubular rotator body 4 having an uphole end 5, a downhole end 7, and a central bore 8 configured to securely receive the string of sucker rods 2 extending longitudinally therethrough. In some embodiments, body 4 may be sized and shaped to house worm wheel 24 therein. Body 4 may be manufactured from any metal or composite as known in the industry.

[0044] According to embodiments, apparatus 10 may comprise a lid or top cap 6, securely engaged to body 4. In some embodiments, top cap 6 may be engaged to body 4 at or near its uphole end 5. Top cap 6 may form a central bore 9, concentrically aligned to and corresponding with central bore 8 of body 4, for at least receiving the string of sucker rods 2 extending therethrough. In some embodiments, as will bedescribed, central bore 9 of top cap 6 may also be sized to receive at least a portion of the worm wheel 24 extending upwardly therethrough.

[0045] In some embodiments, top cap 6 may be rotatably engaged with body 4, such that top cap 6 may be rotatable about a central longitudinal axis a (FIGS. 20 and 3C), whereas body 4 of apparatus 10 remains stationary. In such embodiments, advantageously, top cap 6 may comprise an indicia of rotational movement, i.e. , top cap 6 may comprise a colour, marking, or other visual cue of rotation. In this manner, an operator need only observe the rotation-indicating marking on top cap 6 as visual confirmation of rotational motion of apparatus 10, enabling easy confirmation that rod string 2 is rotating. In other embodiments, top cap 6 may be securely affixed to body 4, such that top cap 6 remains stationary along with body 4.

[0046] In some embodiments, top cap 6 may have an outer surface and an inner surface, the inner surface forming an annular internal groove 12 (FIGS. 20 and 3C). Annular groove 12 may be configured to receive and contain uphole end 5 of body 4, and to sealingly engage therewith. For example, having regard to FIGS. 2C and 3C, in some embodiments, inner surface of top cap 6 and outer surface of body 4 may be configured to receive and contain at least one annular seal 11 therebetween, and outer surfaces of top cap 6 and worm wheel 24 may be configured to receive and contain at least one other annular seal 13 therebetween. In this manner, top cap 6 ensures a secure closure over body, protecting internal componentry housed therein from the environment and external elements. It should be appreciated that any size, location, and configuration of sealed engagement between top cap 6 and body 4 of apparatus 10 is contemplated.

[0047] According to embodiments, apparatus 10 may further comprise a modified worm gear assembly 20.

[0048] By way of background, as above, worm gear assemblies are commonly used in rod rotators to impart rotational movement to the rod string in artificial lift pumping equipment. Known assemblies often comprise a lever arm or ‘actuator’ operably connected to the reciprocating horsehead that, when rotated (ratcheted), arm rotates a worm shaft (a helical screw-like input shaft) meshed with a corresponding worm wheel (output gear) securely gripping the polished rod such that, as the worm shaft rotates, its helical threads engage with the teeth of the worm wheel to transmit controlled rotation of the rod string.

[0049] According to embodiments, having regard to FIGS. 2 - 3, the presently improved worm gear assembly 20 comprises a worm 22 and corresponding worm wheel 24.

[0050] In some embodiments, as would be appreciated, worm 22 may comprise an elongate shaft having a first end and a second end and forming a plurality of helical (spiral) threads about an outer surface between first and second end (not shown). At its first end, worm 22 may be operably connected to lever arm 14, such that, as lever arm 14 is actuated by horse head, arm 14 serving to rotate worm 22 about its longitudinal axis (FIG. 2B and 3B). Helical threads about worm shaft 22 may be configured to correspondingly engage with and to turn helical threads about an outer surface of worm wheel 24.

[0051] In some embodiments, having regard to FIGS. 2B and 3B, worm wheel 24 may comprise a tubular wheel having an uphole end 21 , a downhole end 23, andforming a central bore 25 longitudinally extending therethrough. As described, wheel 24 may, about at least a portion of its outer surface, and between its uphole and downhole ends 21 ,23, form a series of helical threads configured to correspond with helical threads about worm 22 such that, rotation of worm 22 correspondingly rotates wheel 24 (forming the toothed worm ‘gear’). Central bore 25 of wheel 24 may be configured to receive and secure rod 2 extending therethrough. In this manner, rotation of wheel 24 correspondingly rotates rod string 2.

[0052] In some embodiments, having regard to FIGS. 2C and 3C, at its uphole end 21 , worm wheel 24 may form an elongate extension portion 26, such extension portion 26 extending uphole from body and protruding through uphole end 5 of body 4. That is, counterintuitively, extension portion 26 of wheel 24 may extend uphole through top cap 6 and protrude upwardly out of body 4, exposing wheel 24 and rendering it accessible from, outside of apparatus 10 (i.e., elongate worm wheel 24 may penetrate uphole through central bore 8 of body 4). In this manner, worm wheel 24 is designed to interface and rotationally engage with rod clamps 3, increasing the overall torque that can be effectively transferred from the worm wheel 24 to the rod clamps 3 (i.e., reducing risk of slippage therebetween).

[0053] As will be described, advantageously, the direct physical coupling connection between worm wheel 24 and rod clamps 3 can be further enhanced via one or more releasable mechanical interlocks, such as a shear pin, which can serve to supplement the frictional force by providing a direct mechanical linkage (eliminating the need for apparatus 10 to rely upon friction alone).

[0054] In some embodiments, having regard to FIGS. 2B and 3B, extension portion 26 form at least one hole or recess 27 for receiving at least one pin, such as a shear pin 30 (as will be described). As above, pin 30 may provide a positive engagement feature, maintaining synchronization between extension portion 26 and rod clamps 3, reducing localized stress on the frictional interface between the surface and mitigating slippage therebetween. As will be described, in some embodiments, the at least one pin 30 may be configured to shear at a predetermined torque threshold, protecting critical componentry of both the apparatus 10 and pumping equipment from excessive stress or damage in case of an overload.

[0055] According to embodiments, having regard to FIGS. 2D, 4 and 5, at its uphole end 21 , worm wheel 24 may further comprise a wheel cap 28. In some embodiments, wheel cap 28 may have an outer surface, and inner surface, and form a wheel cap bore 35 concentrically aligned with central bore 25 of body 4 for receiving rods 2 therethrough, the inner surface forming configured to sealingly engage at least a portion of worm wheel 24. In this manner, wheel cap 28 ensures a secure closure over extension portion 26 of worm wheel 24 housed within body 4, protecting the worm wheel 24 and other internal components of apparatus 10 from the environment and external elements. When desired, wheel cap 28 may be removed from wheel extension 26, providing access to internal componentry of apparatus 10. For example, as would be appreciated, when desired, rod clamps 3 may be raised such that cap 28 may be lifted from extension portion 26, providing access to the internal componentry of body 4.

[0056] In some embodiments, wheel cap 28 may be configured to form at least one pin bore 29 extending therethrough, pin bore 29 for receiving at least one pin, such as shear pin 30. For instance, shear pins 30 may be used as mechanical indicators of the connection between worm wheel 24 and rod clamps 3 (i.e., ensuring connection is maintained to achieve rotation of rod string 2), with pins 30 being designed to shear (break) when rotational torque imposed on the wheel 24 exceeds a predefined limit. As will be readily appreciated, the presently improved apparatus 10 further enables direct access to pin 30, enabling the maintenance or replacement thereof.

[0057] According to embodiments, having regard to FIG. 2D, apparatus 10 may optionally comprise at least one centralizing tubular rod sleeve or bushing 40. In some embodiments, bushing 40 may be sized and configured to be slidingly received within central bore 25 of worm wheel 24, and positioned at or near uphole end 21 of wheel 24. Bushing 40 may form a central bushing bore 42 for receiving at least one rod 2 extending therethrough, the internal diameter of bore 42 being sized and configured to corresponding with the outer diameter of rod 2. That is, bushing 40 may be specifically configured to serve as a centralizer operative with, without limitation, 1 %”, 1 T ”, 1%” polished rods 2. Bushing 40 may be manufactured of any appropriate materials known in the art including, without limitation, aluminum, plastic, or Nylatron™.

[0058] In some embodiments, bushing 40 may be received within central bore 25 and prevented from moving downhole by wheel 24 (e.g., bushing 40 may ‘hang’ from wheel extension 26). For example, in some embodiments, extension portion 26of wheel 24 may form at least one annular shoulder 41 for abutting a correspondingly annular flange 42 of bushing 40, such abutment for receiving and maintaining bushing 40 in place.

[0059] In some embodiments, advantageously, bushing 40 may further serve to align the at least one pin 30 in position within pin hole 27 or wheel extension 26, providing lateral support adjacent pin 30 to assist pin stability and enhance the pin’s 30 torque transfer performance. Reducing misalignment or external forces imposed upon pin 30 may eliminate lateral (side) loads on the pin 30, preventing it from experiencing bending stress in addition to shear stress. Such lateral support provided by bushing 40 may serve to counter side loads by providing a bracing effect, keeping the pin 30 from shifting or deflecting excessively. Such lateral support provided by bushing 40 may further reduce bending stresses and prevent off-axis forces, ensuring pin 30 sustains a more uniform shear load. For example, because pins 30 may be specifically designed to fail in shear rather than bending, minimizing side loads ensures that the pin 30 can maintain its full rated shear strength, improving its durability and performance, and resulting in longer operational life.

[0060] According to embodiments, having regard to FIGS. 6 and 7, apparatus 10 may further comprise at least one pin 30, such pin 30 operative as a shear pin forming a releasable coupling connection between wheel 24 and rod clamps 3, enhancing rotational engagement therebetween. As will be described, the at least one pin 30 may be sized and shaped to optimize a predetermined shear strength depending upon the rotational forces applied to apparatus 10. For example, pins 30 may be specifically configured to enhance the torque capacity of apparatus 10 (i.e.,the amount of load imposed on apparatus 10), as impacted by the varying sizes of polished rod 2. For example, advantageously, pins 30 may be configured to fail or ‘shear’ at or between approximately 300 ft-lbs and approximately 1 ,300 ft-lbs, optimizing the operational capacity of apparatus 10 when different sizes of rods 2 are used.

[0061] In some embodiments, having regard to FIGS. 7A - 7C, advantageously, shear pin 30 may be configured to form at least one annular groove 32, providing a predetermined, controlled failure point that can be tailored to the specifications of apparatus 10. For example, in some embodiments, groove 32 may comprise a first width 31 (FIG. 7A) providing a pin 30 having a first shear strength (e.g., 300 ft-lb), which may be lower, and thus operative to accommodate less stress on pin 30, than groove 32 having a second width 33 (FIG. 7B) with a second shear strength (e.g., 600 ft-lb), or third width 35 (FIG. 7C) having a third shear strength (e.g., 900 ft-lb), and so on (as outlined in the Table 1 below).

[0062] In some embodiments, without limitation, pins 30 may have a downhole end 37 and an uphole end 39, the downhole end 37 configured to be inserted into and received within pin hole 27 of wheel extension 24, while uphole end 39 extends upwardly therefrom (and through central bore 29 of wheel cap 28). In some embodiments, annular groove 32 may be centrally positioned between uphole and downhole ends 39,37, so as to align with uphole end 21 of wheel extension 26. In this manner, when sheared, a downhole portion of pin 30 may remain within pin recess 27 of worm wheel 24 while an uphole portion of pin 30 is sheared (due to loss of connection between wheel 24 and clamps 30). Pins 30 may comprise custom pinsmanufactured from any suitable materials known in the art, or may be commercially available (e.g., Browning shear pins, McMaster-Carr, USA).

[0063] TABLE 1 : Example Shear Pin Diameters for Varying Shear PinConfigurations

[0064] According to embodiments, having regard to FIGS. 3A - 3C, apparatus may further comprise at least one wedge-like component 60 positioned between worm wheel 24 and rod clamps 3, for further enhancing the torque transmitted between thetop surface of wheel 24 and the bottom surface of clamps 3. For example, without limitation, wedge 60 may create an angled engagement between worm wheel 24, and particularly extension worm extension portion 26, and rod clamps 3 such that, as wheel 24 rotates, wedge 60 serves to frictionally engage surfaces of both wheel 24 and clamps 3 forming an enhanced positive interlock therebetween. Such a configuration may serve to reduce the reliance of apparatus 10 on friction alone, as the angled contact area helps resist relative motion between surfaces. Advantageously, in such embodiments, the presently improved apparatus 10 may enhance torque transmitted by apparatus 10, reducing slipping via increased normal forces (e.g., through wedge 60) as well as mechanical interlocking (e.g., through shear pin 30)

[0065] In some embodiments, wedge may have an outer surface, an inner surface, and may form a central wedge bore 65 for receiving rods 2 extending therethrough.

[0066] In some embodiments, outer surface of wedge 60 may be configured to frictionally engage the bottom surface of the lowermost rod clamp 3. In some embodiments, inner surface of wedge 60 may be configured to frictionally engage the upper surface of wheel 24 (via wheel cap 28). In some embodiments, wedge 60 may form at least one pin recess 67, coaxially aligned with pin hole 27 of wheel 24 (FIG. 3A). In this manner, pin 30 inserted into pin hole 27 may extend upwardly into recess 67 of wedge 60.

[0067] In some embodiments, worm wheel 24 may be configured to rotate freely within body 4 of apparatus 10. For example, having regard to FIG. 2D, body 4may be configured to house at least one, and preferably at least two, bearing assemblies 52,54. Bearing assemblies may comprise any suitable bearings for supporting axial loads of worm wheel 24 applied to clamps 3 such as, without limitation, thrust bearings.

[0068] In some embodiments, at least one first uphole bearing assembly 52 may be positioned at or near uphole end 21 of wheel 24, while at least one second downhole bearing assembly 54 may be positioned at or near downhole end 23 of wheel 24. In some embodiments, the at least one first uphole bearing assembly 52 may be positioned at or about extension portion 26 of wheel 24.

[0069] In some embodiments, as may be appreciated, worm wheel 24 may be operationally coupled to body 4, via at least one of the bearing assemblies 52,54, enabling free rotation of wheel 24 (and rod string 2) within stationary body 4 of apparatus 10. Advantageously, bearing assemblies 52,54 may each alone or in combination serve to assist with alignment of wheel 24 as it rotates within body 4. Also advantageously, the incorporation of at least two bearing assemblies may also enable apparatus 10 to house significantly larger and more robust bearings (e.g., having capacity of approximately 60,000 lbs.

[0070] According to embodiments, having regard to FIG. 5, apparatus 10 may be configured to provide an improved actuator lever arm 14 system, such lever comprising a hexagon shaft 16 for securing an externally housed one-way bearing assembly body with handle 15 and corresponding pin 17. In this manner, one-way bearing assembly and handle 15 may be readily accessed and replaced by simply removing pin 17 to remove handle 15, exposing bearing assembly housed therein.

[0071] According to embodiments, methods for rotating a string of sucker rods 2 during the operation of artificial lift pumping of a subterranean wellbore are provided, the artificial pumping performed artificial pumping equipment having at least one rotator apparatus 10 operably connected to a plurality of rod clamps 3 secured to at least one rod of the rod string 2. In some embodiments, the methods comprise providing a rotator apparatus 10 operably connected to the plurality of rod clamps 3, the apparatus having a stationary body 4 forming a central bore 8 for receiving the string of rods 2 extending therethrough, a worm gear assembly 20 housed within the central bore 8 of the body 4, the worm gear assembly 20 having a worm wheel 24 rotatable by a worm shaft 22, the worm wheel 24 forming a worm wheel extension portion 26 extending uphole through and protruding from the central bore 8 of the body 4, and at least one releasable mechanical interlock 30 positioned between the worm wheel extension portion and at least one of the rod clamps, actuating a lever arm 14 operably connected to the rotator apparatus 10 to rotate the worm 22, thereby rotating the worm wheel 24 and the plurality of rod clamps 3, wherein rotation of the worm wheel 24 transmits rotational motion from the worm wheel extension 26 to the plurality of rod clamps 3 via a combination of frictional engagement and the mechanical interlock 30.

[0072] By way of background, rod float occurs is a problem in the industry that occurs when the rod clamps 3 lift away from the body 4 of the rod rotator apparatus 10, resulting in unintended vertical movement of the rod string 2. This condition can be caused by hydraulic pressure fluctuations, sudden load changes, or mechanical failures in the clamping system. When the clamps 3 lose contact, the rod 2 maymomentarily become unrestrained, leading to potential bouncing or shifting within the wellbore. If not controlled, rod float can cause excessive wear on the rod string, misalignment, or damage to downhole components. Proper system calibration and regular maintenance of the rod handling equipment are essential to prevent this issue.

[0073] According to embodiments, the presently improved apparatus 10 may further comprise at least one customized rod clamp 3, such clamp configured to correspondingly align with apparatus 10 after rod float. For example, in some embodiments, a top surface of apparatus 10 (e.g., wheel cap 28, or wedge 60) may be configured to provide one or more grooves for receiving, in alignment, one or more protrusions on a bottom surface of the lowermost rod clamp 3. While not shown, correspondingly engaged interfaces between apparatus 10 and the lowermost customized rod clamp 3 may be configured to form a cam track, wherein apparatus 10 provides a guided path or groove for controlling movement of a follower or mechanical component of clamp 3, ensuring realignment of clamp 3 relative to apparatus 10 (e.g., during reconnection after rod float). In such embodiments, customized clamp 3 may ensure precise timing and controlled replacement of the rods after rod float. More specifically, in some embodiments, customized rod clamp 3 may be configured to correspondingly connect with wheel cap 28 and wheel 21 , ensuring that, should such componentry become separated during rod float, the componentry would reconnect in alignment.

[0074] Although a few embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications can be made to these embodiments without changing or departing from their scope, intent orfunctionality. The terms and expressions used in the preceding specification have been used herein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and the described portions thereof.

Claims

WE CLAIM:1 ) An apparatus for rotating a reciprocating rod string used in artificial lift pumping equipment, the equipment having a lever arm operably connecting the equipment to the apparatus, the apparatus operably connected to a plurality of rod clamps secured to at least one rod of the rod, the apparatus comprising: a tubular body having an uphole end, a downhole end, and a central bore for receiving the string of rods extending therethrough, a worm gear assembly, rotatably housed within the central bore of the body, the worm gear assembly having, a worm, the worm having an elongate shaft forming a plurality of helical worm threads about an outer surface, a worm wheel, the worm wheel having an uphole end, a downhole end, and forming a plurality of helical wheel threads about an outer surface, the wheel threads corresponding to and engaging with the worm threads, a central wheel bore, the wheel bore in concentric alignment with the central bore of the body, and configured to receive the rod string extending therethrough, wherein, at its uphole end, wheel forms a worm wheel extension portion extending uphole through and protruding from the central bore of the body, at least one releasable mechanical interlock between the worm wheel extension portion and at least one of the rod clamps, wherein, actuation of the lever arm rotates the worm, the helical threads of the worm engaging the corresponding helical threads of the wheel, which then turns the rod clamps and the rod string.2) The apparatus of claim 1 , wherein the at least one mechanical interlock comprises a shearable interlock.3) The apparatus of claim 2, wherein the shearable interlock comprises at least one shear pin.4) The apparatus of claim 3, wherein the worm when extension portion forms a recess for receiving a downhole portion of the at least one shear pin.5) The apparatus of claim 1 , wherein the apparatus further comprises at least one tubular bushing positioned within the central bore for receiving and centralizing the rod strings extending therethrough.6) The apparatus of claim 1 , wherein the apparatus further comprises at least one bearing assembly.7) The apparatus of claim 6, wherein the apparatus further comprises at least two bearing assemblies.8) The apparatus of claim 1 , wherein the apparatus further comprises at least one wedge portion positioned between the worm gear assembly and the rod clamps.9) The apparatus claim 8, wherein the wedge portion forms at least one recess for receiving at least one uphole portion of a shear pin.10)The apparatus of claim 1 , wherein the apparatus may further comprise at least one customized rod clamp having a bottom surface configured to correspondingly interface in alignment with a top surface of the apparatus.11 )A method for rotating a string of sucker rods during the operation of artificial lift pumping of a subterranean wellbore, the artificial pumping performed artificial pumping equipment having at least one rotator apparatus operably connected to aplurality of rod clamps secured to at least one rod of the rod string, the methods comprising: providing a rotator apparatus operably connected to the plurality of rod clamps, the apparatus having a body forming a central bore for receiving the rod string extending therethrough, a worm gear assembly housed within the central bore of the body, the worm gear assembly having, a worm wheel rotatable by a worm shaft, the worm wheel forming a worm wheel extension portion extending uphole through and protruding from the central bore of the body, at least one releasable mechanical interlock positioned between the worm wheel extension portion and at least one of the rod clamps, actuating a lever arm operably connected to the rotator apparatus to rotate the worm, thereby rotating the worm wheel and the plurality of rod clamps, wherein the rotation of the worm wheel transmits rotation motion from the worm wheel extension to the plurality of rod clamps via a combination of frictional engagement and the releasable mechanical interlock. )The method of claim 11 , wherein rotation of the worm gear occurs when helical threads formed on the worm shaft engage corresponding helical threads on the worm gear.13)The method of claim 11 , wherein the at least one releasable mechanical interlock comprises a shear pin and the method further comprises shearing the shear pin when the torque applied to the rod string exceeds a predetermined torque threshold.14)The method of claim 13, wherein the predetermined threshold is based upon the size of the rod string and the method further comprises selecting the shear pin to optimize the predetermined torque threshold.15) The method of claim 11 , wherein the at least one releasable mechanical interlock is operable as a controlled failure point at an interface between the worm wheel extension portion and at least one of the rod clamps.16)The method of claim 11 , wherein the method further comprises removing a wheel cap from the worm wheel extension to replace the releasable mechanical interlock.17)The method of claim 11 , wherein the apparatus provided may further comprise at least one wedge portion positioned between the worm wheel extension and the plurality of rod clamps.18)The method of claim 11 , wherein the worm wheel is rotatable within the central bore of the housing.

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