SEGMENTED RETAINER FOR HIGH-PRESSURE BARRIERS

Abstract

Apparatus and methods for securing a component, such as a sealing element, to a tubular mandrel, such as a downhole tool mandrel, are disclosed. In at least one example, a retaining ring is used to secure the component to a mandrel. The retaining ring is secured to the mandrel by a plurality of discrete retaining segments arranged within a channel defined at least partially by an internal groove in the retaining ring and an external groove in the mandrel. The retaining segments can be individually inserted into the channel through an access opening in the retaining ring. A compression spring can be provided in the channel to provide compression engagement of the retaining segments. Several closing configurations for closing the access opening after the retaining segments have been inserted are also disclosed.

Description

SEGMENTED RETAINER FOR HIGH-PRESSURE BARRIERS CROSS REFERENCE TO RELATED APPLICATIONS This non-provisional application claims priority over U.S. provisional patent application No. 63 / 051,666, the entirety of which is incorporated herein by reference. BACKGROUND OF THE INVENTION A variety of tools are used in the drilling, completion, stimulation, and production of oil and gas wells. These tools are typically tubular to fit the generally round profile of the drilled well and are combined with other tubular tools. For example, a well can be drilled with a drill bit at the bottom of a tubular drill string that is progressively assembled to reach the desired well depth and then pulled out. During drilling, fluid is circulated through the drill string to lubricate the drill bit and remove cuttings. After drilling, a relatively large-diameter tubular casing string can be run down the well and secured by circulating cement at the bottom of the well and through an annular space between the casing and the formation.This casing string reinforces the well and can be drilled to selected depths and intervals to extract hydrocarbon fluids from production zones within the formation. The well can be stimulated by sealing and delivering fluid to the selected production zones. A production tubing string can then be run into the well and extended to the production zone, protecting the casing and providing a flow path to the wellhead through which oil and gas can be produced. In each of the various well operations, it is often necessary to seal between adjacent surfaces, between tubular equipment and / or with the wellbore. For example, during fracturing or cementing operations, various fluids are pumped into the well and hydraulically forced out into the surrounding underground formation. This typically requires sealing the wellbore to provide zonal isolation. Wellbore isolation devices, such as packers, bridge plugs, and fracturing plugs (i.e., “fracturing” plugs), are designed for these general purposes. Such wellbore isolation devices can be used in direct contact with the formation face of the wellbore or with a casing string lining the wellbore walls. A universal challenge in downhole sealing systems is designing robust mechanisms that fit within the narrow confines of the downhole. RQ LQ I η / ΖΖηΖ / Β / ΥΙΛΙ BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of an elongated sealing system coupled to a mandrel by a pair of retaining rings. Fig. 2 is a perspective view of the chuck supported on an optional chuck holder for ease of assembly. Fig. 3 is a side view of one of the retaining rings from Fig. 1 in a process of assembling the retaining ring to the mandrel. Fig. 4 is a cross-sectional view of the retaining ring secured to the mandrel by a retaining segment having a round cross-section. Fig. 5 is a cross-sectional view of an alternative configuration of a retaining ring secured to the mandrel by a retaining segment having a stepped cross-sectional shape. Fig. 6 is a cross-sectional view of yet another alternative configuration of a retaining ring secured to the mandrel by a retaining segment having an I-beam-shaped cross-section. Fig. 7 is a side view of the retaining ring once assembled to the mandrel. Fig. 8 is a side view of another retaining ring configuration that employs a spring in the channel with interlocking end segments at each end of the closure. Fig. 9 is a perspective view of an alternative style of closure with a V-shaped retaining clip. DETAILED DESCRIPTION This disclosure includes devices and methods for securing any of a variety of components to a tubular member of a downhole tool. The disclosed examples are particularly suitable for securing a sealing element to a mandrel, for instance. Aspects of this disclosure are directed toward retaining such a sealing element or other component in a manner that reduces stress on the component during assembly and other related sources of seal failure. The disclosed systems address certain challenges, for example, those arising from gas-tight requirements and high-pressure, high-temperature (HPHT) environments. The disclosed systems and methods are also suitable for dynamic sealing applications where space is limited, where reduced clearances between moving parts are required for seal functionality, and where material systems are pushed to their limits. In some examples, a retaining ring is secured to a mandrel by placing preformed retaining segments in a defined channel between the mandrel and the retaining ring. The channel is jointly defined by an annular groove that extends The EQ LQ Ln / ZZnZ / E / YIAI circumferentially extends along an inner surface of the retaining ring, and a mandrel groove extends circumferentially along an outer surface of the retaining ring. The preformed segments can be individually inserted into the channel through an access opening in the outer surface of the retaining ring and progressively slid into the channel. A closure, which may be materialized as a retaining clip, is used to close the access opening, optionally to fill at least part of the remaining space within the channel not occupied by retaining segments, and to secure the retaining segments within the channel. Several example configurations for the retaining segments, channel, and closure are disclosed, and other example features and benefits are detailed. Figure 1 is a perspective view of a well tool having a compatible sealing element 10 coupled to a tubular mandrel 12 by a pair of retaining rings 40, according to one aspect of this disclosure. The tool 10 is represented, for illustrative purposes, as a downhole seal assembly 10, wherein a sealing element 14 is secured to the mandrel 12. The sealing element 14 can be deployed by inflating or otherwise expanding it outward against an internal surface of a generally circular wellbore 20. The sealing element 14 is secured to the mandrel 12 at opposite ends 15, 16 by the retaining rings 40, which may be substantially identical.The retaining rings 40 secure the ends 15, 16 of the sealing element 14 with sufficient integrity to resist axial forces and movement of the ends 15, 16, such as when the downhole seal assembly 10 is activated within the well 20 and during expansion of the sealing element 14 against the well 20. As discussed later, an annular groove extending circumferentially along an inner surface of each retaining ring 40 and a mandrel groove extending circumferentially along an outer surface of the mandrel 12 together define a circumferentially extending internal channel. A plurality of retaining segments can be arranged circumferentially within the retaining ring 40 channel through an access opening 44. The retaining segments prevent axial movement of the retaining rings 40 in the mandrel 12, axially securing the retaining rings 40 to the mandrel 12. It should be recognized that the downhole seal assembly 10 of Fig.1 is just one example of how 40 retaining rings and alternative configurations thereof can be used to axially secure a sealing member or other component around a mandrel, and other types of seals and even other non-sealed components can be secured to a mandrel by any number of retaining rings. EQ LQ Ln / ZZnZ / E / YIAI Figure 2 is a perspective view of the mandrel 12 supported in an optional mandrel holder 70 to facilitate manual assembly of the downhole seal assembly components, including the retaining ring 40, to the mandrel 12 by a technician or other user. The mandrel holder 70 includes support elements (e.g., cradles) 72 to hold the mandrel 12 at opposite ends. The mandrel 12 can be lifted and placed onto the holder 70 using a lifting tool, such as a crane (not shown). The cradles may include rollers 74 to allow the mandrel to rotate freely about its axis. The retaining ring 40 is placed around the mandrel 12 with the access opening 44 generally facing upward at a height and position convenient for manually inserting the retaining segments 50. A plurality of retention segments 50 can be inserted, one at a time, through the access opening 44.An insertion and / or positioning tool 75 can be used to assist with the assembly of the retaining ring 40 to the mandrel 12. An example of such an insertion or positioning tool 75 may have a narrow, straight section to help seat each retaining segment 50 within the retaining ring 40. The tool 75 can also be used to progressively slide each retaining segment 50 along the channel to allow space for the insertion of the next retaining segment 50. The tool can alternatively be curved to fit the access opening 44 and to facilitate the sliding of the retaining segments 50 along the channel 42. In other cases, a conventional tool such as a small screwdriver may be suitable for pushing the retaining segments circumferentially during installation. Figure 3 is a side view of one of the retaining rings 40 from Figure 1 in the process of assembling the retaining ring 40 to the mandrel 12. The retaining ring 40 and the mandrel 12 are both circular in this example. The retaining ring 40 has been placed on the mandrel 12, with an inner surface 40S on an inner diameter (OD) of the retaining ring 40 positioned very close to and opposite an outer surface 12S on an outer diameter (OD) of the mandrel 12. A circumferential channel 42 is defined between the retaining ring 40 and the mandrel 12 by a respective annular groove and a groove in the mandrel, which are discussed below. In this example, channel 42 is a continuous channel that extends circumferentially 360 degrees along a perimeter (circumference) of retaining ring 40. Alternative configurations may include a channel that extends only partially (less than 360 degrees) along the circumference.The access opening 44 is provided on the outer surface 12S of the retaining ring 40 to the annular groove, for the insertion of each retaining segment 50 into the channel 42. The access opening 44 is sized to individually receive each retaining segment 50. The access opening 44, in this example, is slightly longer than the length “L” of the retaining segment. RQ LQ Ln / ZZnZ / E / YIAI is inserted to receive one retention segment 50 at a time through the access opening 44 in channel 42. Each retention segment 50 can be inserted straight down in the direction of an insertion arrow 45 to seat in channel 42. The retaining segments 50 can be inserted by hand, such as by dropping each one directly into the channel 42, or by using an insertion or positioning tool if necessary. After inserting a particular retaining segment 50, the retaining ring 40 and / or the mandrel 12 can be manipulated, for example, by rotating one relative to the other, to facilitate the movement of the inserted retaining segments 50 along the channel 42 so that additional retaining segments 50 can be inserted. The retaining segments 50 can be inserted individually, one by one, until the desired number of retaining segments 50 have been inserted, such as to partially or completely fill the channel 42. A tool (e.g., tool 75 in Fig. 2) can be used as needed to assist in positioning the retaining segments 50. Each retaining segment 50 shown in Fig. 2 is substantially identical in size and shape in this embodiment, although embodiments could be constructed with different sizes and shapes of retaining segments. The retaining segments 50 seated within the channel 42 extend radially into the annular groove and the mandrel groove that together define the channel 42, creating interference to the axial movement of the retaining ring 40 with respect to the mandrel 12. The plurality of retaining segments 50 can collectively withstand the stress of the external load on the retaining ring 40 and any structure (e.g., a component of the downhole seal assembly) secured by the retaining ring 40 to the mandrel 12.This amount of retention (e.g., amount of axial load supported) may depend, for example, on the shear strength and other material properties of the retaining segments 50, the geometry of the retaining segments 50, the geometry of the channel, and the tolerances and clearance between the retaining segments 50 and the channel 42. It is not necessary for channel 42 to be filled end-to-end with retaining segments 50 to secure retaining ring 40. For example, one or more embodiments can secure the retaining ring by collectively spanning as little as 180 degrees of a 360-degree channel. However, each retaining segment 50 added to channel 42 will generally contribute an increasing amount of strength or retention stability. Therefore, increasing the number of retaining segments 50 in channel 42 to the full 360 degrees of channel 42 can also contribute to the lateral or radial stability of retaining ring 40 relative to mandrel 12 by more completely filling a volume of channel 42. Therefore, in some embodiments LQ Ln / Zznz / E / YIAI implementation, sufficient retaining segments 50 may be provided to substantially fill the channel 42, or leave sufficient room for a closure in the access opening 44 and / or an optional spring or other item occupying some portion of the channel 42 together with the retaining segments 50. Although not strictly required in all embodiments, filling channel 42 with enough retaining segments to collectively span the combined 360 degrees of the channel generally maximizes retention for a given channel and segment configuration. In some embodiments, it is sufficient for the segments to move loosely in the channel and / or fill less than 360 degrees of channel 42 because the tool would experience uniform loading (pressure) on all segments simultaneously. Therefore, in some embodiments, enough retaining segments will be inserted to span at least half the circumference of the channel, i.e., nominally at least 180 degrees of the channel. This may have some advantages in certain applications where less than 360 degrees of retention is sufficient to axially secure the parts, such as reducing the number and cost of parts, weight, or rotational friction.The retaining ring 40 can also be rotationally secured with respect to the mandrel 12 by using a key or discontinuity 47 on the mandrel or retaining ring in the groove 42 to limit the movement of the retaining segments around the mandrel 12. The figure shows only one example of the location of such a key or discontinuity 47, which interferes with the relative rotation between the mandrel 12 and the retaining ring 40. Although a key or discontinuity 47 is shown as an example, additional keys or discontinuities could be circumferentially spaced around the retaining ring 40. A key can be a piece of material added within the groove 42, for example. The key could be formed in the retaining ring by any suitable technique, including, but not limited to, welding or press-fitting the key into the groove of the mandrel.Alternatively, a discontinuity could form simply by not machining the mandrel groove completely around the outer diameter of mandrel 14, but by leaving at least a small segment uncut. This can result in the channel 42 extending less than 360 degrees around the circumference of mandrel 12. Each retaining segment 50 can be pre-formed during manufacturing to fit the channel profile 42. The retaining segments can be formed into any of a variety of shapes. Several manufacturing processes can be used to produce the segments depending on the material, cross-section, and tolerance requirements of the retaining segments 50. Such manufacturing processes include, for example, spring forming, waterjet / plasma cutting, computer numerical control (CNC) machining, additive manufacturing, casting, and machining by EQ LQ Ln / ZZnZ / E / YIAI electrical discharge machining (EDM), as well as others. In addition, the retaining segments can be heat-treated to obtain specific material properties, such as creep resistance and elongation. The retaining segments 50 and channel 42 can also be formed with any of a variety of sizes and cross-sectional shapes. Certain cross-sectional shapes may offer specific advantages or characteristics, such as strength, stiffness, or ease of assembly. Certain cross-sectional shapes (e.g., an I-beam) may include one or more flanges slidably captured within a portion of the annular groove and / or mandrel groove, enabling the retaining segments 50 to assume a radial load in addition to the shear load. Examples of circular, stepped, and I-beam cross-sectional shapes are illustrated in Figures 4, 5, and 6. Fig. 4 is a cross-sectional view (taken along a plane through the axis of mandrel 18) of the retaining ring 40 secured to the mandrel 12 by a retaining segment 150 having a round cross-section. The retaining ring 40 defines a circumferential annular groove 41 around an internal surface 43 of the retaining ring 40. At the same axial location, the mandrel 12 has a circumferential mandrel groove 21 defined on an external surface 23, for example, cut into the external diameter (OD) of the mandrel 12. The annular groove 41 and the mandrel groove 21 together define the channel 42 in which each retaining segment 151 is positioned. The cross-sections of the annular groove 41 and the mandrel groove 21, by way of example and not limitation, have approximately the same dimensions, as if they formed two halves of a circle around the cross-section of the circular retaining segment.The retaining segment 151 has a generally round cross-section that fits into what in this example is a generally circular cross-section of the channel 42. In one or more embodiments, the size of the cross-sections of the retaining segments 151 and the channel 42 can be selected such that the retaining segment 151 extends radially both within the annular groove 41 and in the groove of the mandrel 21. The retaining segments 151 can extend at least radially above the inner surface 43 of the retaining ring 40 and below the outer surface 23 of the mandrel, sufficiently to axially secure the retaining ring 40 in the mandrel 12 under expected loading conditions. Figure 5 is a cross-sectional view (taken along a plane through the axis of the mandrel 18) of an alternative configuration of a retaining ring 140 secured to the mandrel 12 by a retaining segment 250 having a stepped cross-section. A circumferential annular groove 141 and a circumferential mandrel groove 121 define a corresponding stepped channel 142, each having a substantially rectangular cross-sectional shape. The dimensions of the The cross-sectional areas of the annular groove 141 and the mandrel groove 121 differ. For example, the width “A” of the mandrel groove cross-section is greater than the width “B” of the annular groove cross-section. The respective heights “C” and “D” of the annular groove and mandrel groove cross-sections may also differ, due to expected loading conditions, the strength of the materials used, limitations on the wall thickness of the mandrel 12 on which to define a groove profile, and so on. Figure 6 is a cross-sectional view (taken along a plane through the axis of the mandrel 18) of yet another alternative configuration of a retaining ring 240 secured to the mandrel 12 by a retaining segment 350 having an I-beam cross-section, arranged in an I-beam channel 242. The I-beam channel is defined by a circumferential annular groove 241 and a circumferential mandrel groove 221, both of which have a substantially rectangular cross-sectional shape. The I-beam retaining segment 350 provides additional radial stability to secure the retaining ring 240 in a radial direction indicated by “R”. For example, the I-beam cross-section includes a flange 354, 356 at each end, each of which is captured in the corresponding portions 244, 246 of the annular groove and the mandrel groove. Those in the mid-level trade who benefit from this information will appreciate, without further illustration, that countless cross-sectional shapes are possible beyond these specific examples. Having analyzed the various retaining segments and possible channel geometries, the analysis returns to the assembly using retaining ring 40 and retaining segment 50 in Fig. 3. Figure 7 is a side view of the retaining ring of Figure 3 once the channel 42 has been filled with as many retaining segments 50 as will fit, with sufficient clearance for a closure 60. The closure is used to close the access opening 44 after all the retaining segments 50 have been inserted into the channel 42. The closure 60 can also be extended radially within the channel to fill any remaining circumferential space between the retaining segments 50 at either end of the closure 60. In this embodiment, the closure 60 is configured more specifically as a retaining clip, which can be snapped into place to prevent the loss or unintentional removal of the retaining segments 50. The closure 60 is inserted into the channel 42 through the access opening 44 and can be removably locked in place by engaging an internal portion of the retaining ring 40.The retaining segments 50 together with the closure 60 now span the entire perimeter (circumference) of channel 42, and are supported end to end. EQ LQ Ln / ZZnZ / E / YIAI Figure 8 is a side view of another retaining ring configuration that employs a compression spring 170 and interlocking end segments 90 at each end of the closure 160. As in the previous examples, the retaining ring uses interference between the retaining segments in a channel defined by an annular groove and a mandrel groove to axially secure the retaining ring 40 to the mandrel. The retaining segments 50 still fill most of the channel 42 but leave sufficient space in the channel 42 for the spring 170 and the closure 160. The spring 170 provides circumferential compression between any moving members within the channel 42, including between adjacent retaining segments 50 and between the interlocking end segments 90 and the closure 160. A tool (e.g., tool 75 in Figure 8) can be designed to accommodate the compression spring 170 and interlocking end segments 90 and the closure 160.2) so that it fits within the access opening 44 during assembly to push the end retaining segment 60 circumferentially slightly outwards, compressing the spring 170 and creating enough space to insert the closure 160. The end segments 90, which may be referred to as interlocking end segments, include features that interlock with the closure 60 and remain interlocked while compression-coupled due to the compression provided by spring 170. In this embodiment, an end segment 90 is provided on each side of the closure 160, which can function like other retaining segments 50 in terms of interfering with the axial movement of the retaining ring. The end segments 90 also include an end portion 91 that overlaps with an end portion 161 of the closure 160. During assembly, after the retaining segments 50 and the end segments 90 have been inserted into the channel, the interlocking end segments can be pushed outward against the compressive force provided by spring 170 to provide sufficient space in the access opening 44 to insert the closure 160.In particular, the end segments 90 can be separated sufficiently to create clearance between the overlapping end parts 91, 161 to insert the closure 160 into the channel 42. The spring 170 can then circumferentially drive the interlocking end segments within the channel 42 so that they are supported again by the closure 160 and the overlapping end features 91, 161. The overlapping end features 91, 161 on each side prevent or resist inadvertent removal of the closure 160 and loss of the retaining segments 50. Any closure suitable for closing an access opening is also within the scope of this disclosure. Fig. 9 is a perspective view of a closure configuration comprising an alternative style of closure 60, with a V-shaped retaining clip (i.e., “V-clip”), viewed from the inside of the retaining ring 40 facing the access opening 44. The “V” shape allows the closure 60 to flex or deform inward to fit into the access opening in the direction of AQ LQ I η / ZZΖηZ / B / YILI arrow insertion 45 to ensure that the segments remain within the channel. Then, the closure 60 snaps outward and engages with an internal retaining surface 46 within the retaining ring 40 to prevent it from being pulled out. Accordingly, this disclosure provides various devices, methods, and tools for securing a component such as a sealing element to a tubular mandrel of a downhole tool. These may include any of the various features disclosed herein, which include one or more of the following statements. Declaration 1. An apparatus comprising: a mandrel defining a mandrel groove extending circumferentially along an external surface of the mandrel; a retaining ring defining an annular groove extending circumferentially along an internal surface of the retaining ring and an access opening to the annular groove from an external surface of the retaining ring, the retaining ring being positionable around the mandrel to jointly define a channel with the annular groove and the mandrel groove; and a plurality of retaining segments that can be inserted through the access opening into the channel to axially secure the retaining ring to the mandrel. Declaration 2. The apparatus according to declaration 1, further comprising a spring that is inserted through the access opening into the channel to place the plurality of retaining segments in circumferential compression within the channel. Declaration 3. The apparatus according to declaration 1 or 2, further comprising: a closure that can be removably secured to the retaining ring to close the access opening and secure the plurality of retaining segments in the channel. Statement 4. The apparatus according to any of statements 1 to 3, wherein the plurality of retaining segments comprises two end segments disposed in the channel on opposite sides of the access opening, and the closure extends radially into the channel between the two end segments. Declaration 5. The apparatus in accordance with declaration 4, wherein the end of at least one of the end segments has an interlocking end that interlocks with the closure that extends radially into the channel. Declaration 6. The apparatus in accordance with declaration 5, wherein the end of at least one of the end segments overlaps circumferentially with a portion of the closure. Declaration 7. The apparatus according to any of declarations 1 to 6, further comprising a key formed along one or both annular grooves and the mandrel groove for limiting the circumferential movement of the retaining segments along the channel. RQ LQ Ln / Zznz / E / YIAI Declaration 8. The apparatus in accordance with any of declarations 1 to 7, wherein the plurality of the retaining segments cover at least 180 degrees of the channel. Declaration 9. The apparatus according to any of declarations 1 to 8, wherein one or more of the retaining segments comprise a stepped cross-section including a radially internal portion and a radially external portion, the radially external portion having a greater width than the width of the radially internal portion. Statement 10. The apparatus according to any of statements 1 to 9, wherein one or more of the retaining segments has a beam-shaped cross section that includes one or both of a flanged end slidably captured within the annular groove and a flanged end slidably captured within the mandrel groove when inserted into the channel. Declaration 11. The apparatus in accordance with any of declarations 1 to 10, further comprising: a sealing member secured to the mandrel by the retaining ring and configured to deploy outwards from the mandrel. Declaration 12. A downhole tool, comprising: a mandrel defining a mandrel groove extending circumferentially along an external surface of the mandrel; a retaining ring defining an annular groove extending circumferentially along an internal surface of the retaining ring and an access opening to the annular groove from an external surface of the retaining ring, the retaining ring being positionable around the mandrel to jointly define a channel with the annular groove and the mandrel groove; a plurality of retaining segments that can be inserted through the access opening into the channel to axially secure the retaining ring to the mandrel; a spring that can be inserted through the access opening into the channel to place the plurality of retaining segments in circumferential compression within the channel;and a sealing member secured to the mandrel by the retaining ring and configured to deploy outwards from the mandrel. Statement 13. The downhole tool according to Statement 12, further comprising: a closure that can be removably secured to the retaining ring to close the access opening and secure the plurality of retaining segments in the channel; wherein the plurality of retaining segments comprises two end segments disposed in the channel on opposite sides of the access opening, and the closure extends radially into the channel between the two end segments; and wherein each end segment has an interlocking end that interlocks with the closure by circumferentially overlapping with a portion of the closure when coupled by compression from the compression spring. RQ LQ Ln / Zznz / E / YIAI Declaration 14. A method for securing a component to a well tool, comprising: placing a retaining ring on a mandrel of the well tool; and inserting a plurality of retaining segments through an access opening in a retaining ring and into a channel defined between an annular groove in the retaining ring and a mandrel groove in the mandrel. Declaration 15. The apparatus in accordance with declaration 14, further comprising: ensuring a closure to the retaining ring to close the access opening after inserting the plurality of retaining segments into the channel. Statement 16. The method in accordance with statement 14 or 15, further comprising inserting a compression spring through the access opening in the channel to place the plurality of retaining segments in circumferential compression within the channel. Statement 17. The method in accordance with any of statements 14 to 16, further comprising filling at least 180 degrees of the channel with the plurality of retention segments. Statement 18. The method in accordance with any of statements 14 to 17, further comprising: securing a sealing member to the mandrel with the retaining ring. Declaration 19. The method of Declaration 18, further comprising: further securing the sealing member to the mandrel by placing a second retaining ring around the mandrel and inserting a second plurality of retaining segments through an access opening in the second retaining ring and into a channel defined between an annular groove in the second retaining ring and another mandrel groove in the mandrel. Statement 20. The method in accordance with any of statements 14 to 19, wherein each retaining segment comprises a circular cross-section, a stepped cross-section, or a beam-shaped cross-section. For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower bound may be combined with any upper bound to refer to a range not explicitly stated, and ranges from any lower bound may be combined with any other lower bound to refer to a range not explicitly stated; likewise, ranges from any upper bound may be combined with any other upper bound to refer to a range not explicitly stated. Furthermore, whenever a numeric range with a lower and upper bound is disclosed, any number and any included range within that range are specifically disclosed. In particular, it should be understood that each range of values ​​(of the form “from around a to around b,” or, in a manner RQ LQ Ln / Zznz / E / YIAI (equivalent to "approximately aab" or "approximately ab") disclosed herein establishes each number and range encompassed within the broader range of values, even if not explicitly stated. Therefore, each individual point or value may serve as its own lower or upper bound, combined with any other individual point or value or any other lower or upper bound, to enumerate a range not explicitly listed. Therefore, the present embodiments are well-suited to achieve the aforementioned purposes and advantages, as well as those inherent therein. The particular embodiments disclosed above are merely illustrative, as the present embodiments may be modified and implemented in different but equivalent ways that are obvious to persons of a mid-level skill who benefit from the teachings herein. Although individual embodiments are discussed, all combinations of each embodiment are contemplated and covered by the disclosure. Furthermore, it is not intended to limit the details of construction or design shown herein, except as described in the following claims. Additionally, the terms in the claims have their common meaning unless explicitly and clearly defined otherwise by the patent holder.Therefore, it is evident that the particular illustrative embodiments disclosed above may be altered or modified, and that all such variations are considered within the scope and spirit of this disclosure.

Claims

1. An apparatus comprising: a mandrel defining a mandrel groove extending circumferentially along an external surface of the mandrel; a retaining ring defining an annular groove extending circumferentially along an internal surface of the retaining ring and an access opening to the annular groove from an external surface of the retaining ring, the retaining ring being positionable around the mandrel to jointly define a channel with the annular groove and the mandrel groove; and a plurality of retaining segments that can be inserted through the access opening into the channel to axially secure the retaining ring to the mandrel.

2. The apparatus according to claim 1, further comprising a spring that is inserted through the access opening into the channel to place the plurality of retaining segments in circumferential compression within the channel.

3. The apparatus according to claim 1, further comprising: a closure that can be removably secured to the retaining ring to close the access opening and secure the plurality of retaining segments in the channel; and optionally, wherein the plurality of retaining segments comprises two end segments disposed in the channel on opposite sides of the access opening, and the closure extends radially into the channel between the two end segments, and optionally, wherein at least one of the end segments has an interlocking end that interlocks with the closure extending radially into the channel, and optionally, wherein the end of at least one of the end segments circumferentially overlaps with a portion of the closure.

4. The apparatus according to claim 1, further comprising a key formed along one or both annular grooves and the mandrel groove to limit the circumferential movement of the retaining segments along the channel.

5. The apparatus according to claim 1, wherein the plurality of retaining segments covers at least 180 degrees of the channel.

6. The apparatus according to claim 1, wherein one or more of the retaining segments comprises a stepped cross-section or a beam-shaped cross-section, wherein the stepped cross-section includes a radially internal portion and a radially external portion, wherein the radially external portion RQ LQ Ln / ZZnZ / E / YIAI has a greater width than the width of the radially internal portion, wherein the beam-shaped cross-section includes one or both of a flanged end slidably captured within the annular groove and a flanged end slidably captured within the mandrel groove when inserted into the channel.

7. The apparatus according to claim 1, further comprising: a sealing member secured to the mandrel by the retaining ring and configured to deploy outwards from the mandrel.

8. A downhole tool comprising: a mandrel defining a mandrel groove extending circumferentially along an external surface of the mandrel; a retaining ring defining an annular groove extending circumferentially along an internal surface of the retaining ring and an access opening to the annular groove from an external surface of the retaining ring, the retaining ring being positionable around the mandrel to jointly define a channel with the annular groove and the mandrel groove; a plurality of retaining segments that can be inserted through the access opening into the channel to axially secure the retaining ring to the mandrel; a spring that is inserted through the access opening into the channel to place the plurality of retaining segments in circumferential compression within the channel;and a sealing member secured to the mandrel by the retaining ring and configured to deploy outwards from the mandrel.

9. The downhole tool according to claim 8, further comprising: a closure that can be removably secured to the retaining ring to close the access opening and secure the plurality of retaining segments in the channel; wherein the plurality of retaining segments comprises two end segments disposed in the channel on opposite sides of the access opening, and the closure extends radially into the channel between the two end segments; and wherein each end segment has an interlocking end that interlocks with the closure by circumferentially overlapping with a portion of the closure when engaged by compression from the compression spring.

10. A method for securing a component to a well tool, comprising: placing a retaining ring on a mandrel of the well tool; and inserting a plurality of retaining segments through an access opening in a retaining ring and into a channel defined between an annular groove in the retaining ring and a mandrel groove in the mandrel.

11. The method according to claim 10, further comprising: ensuring a closure to the retaining ring to close the access opening after inserting the plurality of retaining segments into the channel.

12. The method according to claim 10, further comprising inserting a compression spring through the access opening in the channel to place the plurality of retaining segments in circumferential compression within the channel.

13. The method according to claim 10, further comprising filling at least 180 degrees of the channel with the plurality of retention segments.

14. The method according to claim 10, further comprising securing a sealing member to the mandrel with a retaining ring, and optionally placing a second retaining ring around the mandrel and inserting a second plurality of retaining segments through an access opening in the second retaining ring and into a channel defined between an annular groove in the second retaining ring and another mandrel groove in the mandrel.

15. The method according to claim 10, wherein each retaining segment comprises a circular cross-section, a stepped cross-section, or a beam-shaped cross-section.

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