Buffer system

Abstract

BUMPING SYSTEM. A buffering system including: a tubular buffer element including a tubular body, an upstream tubular connection and a downstream tubular connection; wherein: the upstream tubular connection and the downstream tubular connection are openings at opposite ends of the tubular body; and a buffer assembly arranged in a housing including: a buffer; a fragmenting object; and a seat; wherein: the buffer is supported by the seat; there is a fluid connection between the upstream tubular connection and the downstream tubular connection; and the tubular body is a single continuous piece; and wherein the buffer assembly is entirely arranged within the tubular buffer element; and the buffer assembly has a first position and a second position; additionally: the buffer assembly is arranged according to: option A wherein: in the first position, the buffer is intact; in the second position the buffer has been broken by the fragmenting object;and the buffer is stationary relative to the housing in both the first and second positions; and / or option B where: in the first position, the buffer is not in contact with the shredding object; and in the second position the buffer is in contact with the shredding object.

Description

BUFFER SYSTEM Field of Invention

[001] The present invention relates to a pressure differential-deactivated plugging assembly for use in oil wells. The present invention also relates to a plugging system comprising said plugging assembly. More particularly, the assembly is for the temporary blocking of fluid flow through a tubular element.

[002] During the drilling, testing, completion, fracturing, production, and abandonment stages of hydrocarbon wells, there are many uses for plug assemblies that create a fluid barrier in the well. Some of these uses are not permanent, such as plugging and abandonment, but rather temporary, where it is desired to re-establish fluid flow at a later stage. Some examples of such temporary uses of plugs are for flotation, well testing during completion, packer adjustment, and fluid loss devices.

[003] Flotation is used in horizontal parts of a well to reduce friction in the borehole when the casing or inner casing is put into place in the well. An air chamber is then formed in the tubing between a mechanical valve or plug assembly at the bottom (the thumb) of the casing and a plug assembly installed further towards the surface, usually in the portion of the well where it becomes vertical (the heel). This allows the casing or inner casing in the horizontal part of the well to float into place, after which the plug assembly must be removed or opened and the valve opened to leave the well ready for subsequent operations such as cementing, pressure testing and production.

[004] As the well is completed, the integrity of the casing and production tubing is tested to ensure there is no leakage during the various conditions expected during oil and gas production. It is then necessary to be able to isolate sections of the well and test them. Petition 870220085558, dated 09 / 19 / 2022, page 18 / 70 / 33 separately. When installing a plug assembly it is possible to perform this test, and then the plug assembly must be opened or removed before production.

[005] Plug assemblies can also be used as a barrier in the production piping, allowing it to be pressed when a plug must be fitted to seal the annular space between the production piping and the casing. It is necessary to open or remove the plug assembly afterwards.

[006] The buffer assembly according to the present invention is suitable for the uses mentioned above, but these are only examples of use and not a limiting list; the buffer assembly can also be used for other applications below. Fundamentals

[007] There are many types of plug assemblies that can be removed or deactivated / opened. The plug assembly can, for example, be removed from the well using flexible tubing or steel cable. But this can lead to problems, such as damage to the tubing, and consume a lot of valuable rig time. The plug assembly can also be drilled or milled, but this has similar disadvantages. The plug assemblies mentioned generally comprise metal plugs, and their removal often results in the presence of unwanted parts or pieces of debris in the well. Plugs can also be made of dissolvable materials, but the conditions under which they are to be used must be very well known and appropriate for the particular dissolvable material, and this does not allow for deviations from the schedule.Other materials, such as rubber or composites, also have disadvantages, often related to their sensitivity to the high pressure and temperature found in many wells, as well as the chemically aggressive environment within them.

[008] Frangible materials, such as glass or ceramics, have the advantage of being relatively insensitive to pressure, temperature, and chemical corrosion. Petition 870220085558, dated 09 / 19 / 2022, page 19 / 70 / 33, but, due to their frangible nature, they are relatively easy to destroy when used as part of fluid blocking of plug assemblies. Glass, in particular, can be broken into very small pieces that will not be a problem in most wells. Frangible materials, therefore, allow for additional ways to open the plug assembly, such as constructing the plug assembly with small amounts of explosives that will crush or break a glass disc and open the plug assembly, but will not damage the production tubing or the plug assembly casing. However, when using explosives, there is always the risk of explosives or parts thereof remaining unexploded in the well, and transportation and handling during the installation of explosive-equipped plugs is complicated, as many safety-related conditions must be taken into account.Breaking frangible discs into sets of buffers without using explosives is therefore advantageous.

[009] In general, the means for opening a plug assembly by destroying a plug such as a frangible disc contained therein are usually incorporated into, or placed on, or in contact with the plug, but may also be placed at some distance from the plug but still within the plug assembly, i.e., in the plug assembly housing. Normally, said means are installed as part of, or at the same time as, the plug assembly.

[0010] The simplest way to destroy a frangible disk is to apply direct force to it with a shredder. This allows for simple mechanical solutions. The shredder will then make contact with the frangible disk in a relatively small area, the disk's impact surface. Brittle materials, such as glass and ceramics, can be designed to withstand the high pressures found in hydrocarbon wells, but if exposed to impact in only a very small area, they typically break, and this property of breaking under a large point pressure load is Petition 870220085558, dated 09 / 19 / 2022, page 20 / 70 / 33, exploited by employing a shredder with a relatively small impact area. The shredder can be a thin edge, like a knife blade, a point, like a pin, or even a small ball or other rounded structure, since only a very small part of it would come into contact with the frangible disc. The shape of the shredder is less important than the fact that the contact area between the shredder and the impact surface of the plug is small, so that relatively small amounts of force applied relatively quickly can break the plug. It is also possible to weaken the plug at the point of contact during its construction so that it is crushed more easily.

[0011] Relative movement is also necessary, i.e., the fragmenter must move relative to the plug. This can be achieved with either the plug or the fragmenter moving towards each other, depending on the type of frangible disc breaking system employed. Different systems have been developed to achieve this, including the use of electrical signals and hydraulic fluids and pressure. Since it is possible to control how much pressure is applied to the plug assembly and plug it directly from the surface, it is possible to use this pressure directly to break the plug. This is an elegant and simple solution, as it does not require signals of any kind to be routed from the surface to the plug assembly; simply applying pressure from the wellhead mechanically drives the movement of the fragmenter over the disc impact surface.This wellhead pressure is then often counterbalanced by the pressure from the borehole below, i.e., from the hydrocarbon formation. The specific pressure that is then required to open a given set of plugs is therefore the pressure differential between the pressures applied from both the borehole below and the borehole above.

[0012] Another way to remove a fragile tampon is to break it in place. In other words, the tampon doesn't need to move relative to the Petition 870220085558, dated 09 / 19 / 2022, page 21 / 70 / 33 fragmenter. This can be done using an explosive. The explosive is then installed so that, when it explodes, it breaks the cap. The explosive thus acts as a fragmenter. Another example of breaking the frangible cap in place is simply applying sufficient pressure from the wellhead to cause the cap to break against an element with which it is in contact.

[0013] The details of how this operation occurs vary among known systems. When designing such a system, several considerations must be taken into account: It is desirable to use the fewest possible number of components, and especially the fewest possible number of moving components, to minimize the risk of said components breaking or becoming stuck during operation and to facilitate their manufacture.

[0014] It is crucial to avoid accidental activation, i.e., accidental or premature breakage of the plug. The system should therefore preferably include safety measures to prevent this.

[0015] The plug must be installed in such a way that it is securely fastened and does not break unintentionally due to fluctuating well pressures (i.e., direct pressure rather than the impact of a fragmenter).

[0016] The plug should preferably be fixed in such a way that it forms a leak-proof barrier to the fluid in the pipe where it is installed until it is broken.

[0017] The plug should preferably break into fragments small enough not to be a potential problem in the well.

[0018] The various parts of the plug assembly should preferably be prevented from entering the wellbore, so that they or parts thereof do not pose a potential problem in the well.

[0019] The various parts of the buffer assembly should be prevented from moving, preferably once the buffer assembly is opened. Petition 870220085558, dated 09 / 19 / 2022, page 22 / 70 / 33

[0020] Fluid leakage between the tubular plug element and the surrounding area, such as the ring, should be avoided as much as possible.

[0021] There should be no possibility of a partial opening of the plug, i.e., the system should preferably only allow the plug to be fully intact or fully broken, not partially broken. If partially broken, it would not be possible to fully open it with pressure from above, as a partially opened plug assembly could not be pressurized, therefore different means to fully open it would have to be used.

[0022] The internal diameter of the pipe in which the plug assembly is installed should preferably be fully restored after opening the plug assembly, i.e., the plug assembly should not have an internal diameter smaller than the internal diameter below and above the plug assembly. This allows unrestricted fluid flow through the open plug assembly. Brief Summary of the Invention

[0023] As described above, there is a need for plug assemblies comprising a frangible disc that can be opened by controlled application of pressure over the plug assembly. The technical problems with existing plug assemblies are generally related to the fact that they are not robust enough and may include many parts, especially moving parts, increasing the chance of malfunction, particularly in adverse well conditions with high pressure and / or temperature and highly corrosive fluids. It is, therefore, the object of the present invention to provide a plug assembly comprising a plug that can maintain pressure while being used for its purpose and then be safely and completely opened after serving its purpose with a mechanism for breaking the plug that is strong enough to support the frangible disc and capable of breaking the disc in a controlled and predictable manner. Petition 870220085558, dated 09 / 19 / 2022, page 23 / 70 / 33 frangible with a fragmenter. The plug assembly must be designed so that rupture occurs at a specific and predefined pressure value applied above the plug assembly. This predefined value must be predictable and repeatable. It must be possible to change the plug assembly parts by altering them as little as possible, so that it is feasible to produce plug assemblies with different differential opening pressure values. Once opened, the plug assembly parts must remain in place and said parts or pieces must not enter the wellbore. The plug assembly according to the present invention provides these advantages.

[0024] In some respects, the techniques described herein refer to a plugging system including: a tubular plugging element including a tubular body, an upstream tubular connection and a downstream tubular connection; wherein: the upstream tubular connection and the downstream tubular connection are openings at opposite ends of the tubular body; and a plug assembly arranged in a housing including: a plug; a fragmenting object; and a seat; wherein: the plug is supported by the seat; there is a fluid connection between the upstream tubular connection and the downstream tubular connection; and the tubular body is a single continuous piece; and wherein the plug assembly is entirely arranged within the tubular plug element; and the plug assembly has a first position and a second position; Furthermore: the buffer assembly is arranged according to: option A where: in the first position, the buffer is intact; in the second position, the buffer has been broken by the fragmenting object; and the buffer is stationary relative to the housing in both the first and second positions; and / or option B where: in the first position, the buffer is not in contact with the shredding object; and in the second position the buffer is Petition 870220085558, dated 09 / 19 / 2022, page 24 / 70 / 33 in contact with the shredding object.

[0025] In some respects, the techniques described herein refer to a buffer system, in which the fragmenting object is an explosive.

[0026] In some respects, the techniques described here refer to a buffer system, in which the shredding object is the seat.

[0027] In some respects, the techniques described herein refer to a buffer system, in which the shredding object is stationary relative to the buffer between the first and second positions.

[0028] In some respects, the techniques described herein refer to a buffer system, wherein the buffer assembly additionally includes a shear ring, wherein the shear ring is arranged in such a way that when a threshold pressure differential is applied to a buffer surface, the shear ring shears and permits axial movement of the seat.

[0029] In some respects, the techniques described in this document refer to a buffer system, wherein the shear ring additionally includes a shear ring body and a shear ring rim, wherein the shear ring rim supports the seat in the first position, the shear ring arranged to shear between the shear ring rim and the shear ring body when the buffer assembly moves from the first to the second position; and wherein the seat additionally includes a retaining rim, wherein the retaining rim is arranged so as to prevent the shear ring rim from moving in an axial and / or radial direction when in the second position.

[0030] In some respects, the techniques described in this document refer to a buffer system, wherein the buffer assembly additionally includes an assembly retainer arranged to support the shredding object and the assembly retainer is stationary relative to the Petition 870220085558, dated 09 / 19 / 2022, p. 25 / 70 / 33 accommodation.

[0031] In some respects, the techniques described in this document refer to a buffer system, in which the assembly retainer supports the shear ring.

[0032] In some respects, the techniques described in this document refer to a plug system, in which the assembly retainer includes threads for securing the assembly retainer to the housing.

[0033] In some respects, the techniques described herein refer to a plug system, wherein the assembly retainer additionally includes a retainer body and wherein the retainer body includes threads for securing the assembly retainer to the housing.

[0034] In some respects, the techniques described in this document refer to a buffer system, in which the assembly retainer additionally includes a plurality of retainer segments.

[0035] In some respects, the techniques described herein refer to a buffer system, wherein at least one of the plurality of Retainer Segments includes a retaining body and a Retainer Projection, wherein the Retainer Projection extends from the retaining body in a radial direction.

[0036] In some respects, the techniques described in this document refer to a buffer system, wherein the buffer system additionally includes a retainer ring for securing the retainer segments to the housing, wherein at least a portion of the retainer body is arranged between the housing and a portion of the retainer ring.

[0037] In some respects, the techniques described in this document refer to a buffer system, wherein the buffer assembly additionally includes an assembly retainer arranged to directly or indirectly support the shear ring and the assembly retainer is stationary with respect to the housing. Petition 870220085558, dated 09 / 19 / 2022, p. 26 / 70 / 33

[0038] In some respects, the techniques described in this document refer to a buffer system, wherein the buffer assembly additionally includes an assembly retainer arranged to support the seat and the assembly retainer is stationary with respect to the housing. Brief Description of the Drawings

[0039] The above and other features of the invention are presented in detail in the appended claims, and their advantages will become clearer from consideration of the following detailed description. Embodiments of the present invention will now be described, by way of example only, with reference to the following diagrams in which: Figure 1 depicts a cross-sectional side view of a buffer system.

[0040] Figure 2A depicts an approximate cross-sectional view of the buffer assembly in a first position.

[0041] Figure 2B depicts an approximate cross-sectional view of the buffer assembly in a second position.

[0042] Figure 2C depicts an approximate cross-sectional view of the buffer assembly in a third position.

[0043] Figures 3A and 3B depict an embodiment of the plugging system of the components of a tubular plugging element and a plugging assembly in an exploded view.

[0044] Figures 4A-4D depict the buffer system as it moves from a first to a third position.

[0045] Figures 5A and 5B depict an embodiment of the plug system and plug assembly in which the tubular plug element is made of two different tubular sections.

[0046] Figure 6 describes an embodiment of the retainer with a retainer damper.

[0047] Figures 7A-7C depict one embodiment of the retainer in Petition 870220085558, dated 09 / 19 / 2022, page 27 / 70 / 33 segments.

[0048] Figures 8A-7B describe one embodiment of the system of A plug with a retainer so that the plug does not move.

[0049] Figure 9 describes one embodiment of the buffer system. where the tampon does not move.

[0050] Figure 10A-B describes one embodiment of the system of A plug containing an explosive. Reference numbers and corresponding elements

[0051] 1 Tubular plug element 11 Housing 12 Tubular body 13 Upstream tubular connection 14 Downstream tubular connection 15 First tubular section 16 Second tubular section 2 Plug 21 Sealing element 22 Bearing ring 3 Shredder assembly 31 Shredder support 32 Shredder object 33 Retaining ring pocket 4 Seat 41 Seat body 42 Retaining flange 43 Pressure ring 44 Shredder pocket 45 Retaining ring groove 5 Shear ring Petition 870220085558, dated 09 / 19 / 2022, page 28 / 70 / 33 Shear Ring Body Shear Ring Edge Assembly retainer Retainer Body Retainer Connector Top of the Retainer Retainer Shock Absorber Retainer Segments Retainer Protrusion Retaining ring 100 Tampon Set 200 Plug System Detailed description of the invention

[0052] Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Alternative embodiments will also be presented. The drawings should be read in conjunction with the abstract, the detailed description and any preferred and / or particular embodiments specifically discussed or otherwise described. This invention can, however, be implemented in many different ways and should not be interpreted as being limited to the embodiments set forth herein. These embodiments are provided for illustrative purposes only. Various other embodiments, or combinations of the embodiments presented, will be within the scope of one skilled in the art.

[0053] The present invention is a buffer assembly that is arranged in a tubular element.

[0054] In the examples described in Figures 1-7C, the buffer assembly has three positions. In the first position, the buffer rests on a seat and is intact, preventing fluid flow through the tubular element. Petition 870220085558, dated 09 / 19 / 2022, pp. 29 / 70 / 33 When a pressure differential is applied to the plug that exceeds a predetermined limit, the plug and plug seat will move in the axial direction. By pressure differential is meant the difference between the pressure from the downhole and the uphole across the plug. Typically, there is upward pressure exerted by the fluids in the formation, i.e., from the downhole, while pressure is applied from the uphole by pumping from the wellhead. Eventually, the plug seat will move into the second position. In the second position, the plug comes into contact with a fragmenting object. Contact with the fragmenting object will cause the plug to break. Note that the invention can be arranged such that it is the pressure from the downhole that triggers the plug breakage, but it is more common for the pressure from the top of the well to be used for this purpose.

[0055] Next, the plug assembly will move to a third position. In the third position, the plug seat is locked in place by a retaining ring. The retaining ring is designed to expand or contract. Being held in a position under tension, it will expand or contract when aligned with a groove or recess where it has room to move into. The retaining ring prevents the plug seat from moving in the axial direction. The second and third positions can occur simultaneously. Note that the reference to the plug system being in the first, second, or third position is the same as the plug assembly being in the first, second, or third position (and vice versa).

[0056] Directional terms such as up, down, left, right, above, below, etc. are being used in reference to the orientation of elements in the figures. This is by no means intended to be limiting.

[0057] Reference is made to Figure 1. Figure 1 depicts a cross-sectional side view of a 200 plug system. The 200 plug system comprises a tubular plug element 1 and an assembly of Petition 870220085558, dated 09 / 19 / 2022, page 30 / 70 / 33 plug 100. The tubular plug element 1 comprises the tubular body 12 with a through hole. The through hole has an upstream tubular connection end 13 and a downstream tubular connection 14 at the opposite end. There is a plug assembly 100 arranged between the upstream tubular connection 13 and the downstream tubular connection 14. The position of the plug assembly 100, as shown, blocks the fluid connection through the tubular plug element 1. The plug assembly 100 shown is arranged in a housing 11. The housing 11 is arranged in the tubular body 12. In the figures shown, the housing 11 is the portion of the tubular body 12 that has been shaped to accommodate the plug assembly 100. However, it may also be a separate element.

[0058] The tubular body 12 shown in the figure is a single continuous piece. The single continuous piece provides a more rigid and stronger tubular plug element 1. Furthermore, it does not require welds or seals necessary when joining two tube sections that enclose the plug assembly 100. These welds or seals can become areas where fluid can leak from the tubular element itself; particularly in high pressure / temperature environments.

[0059] It is possible that the housing 11 is arranged in an element between the tubular body 12 and the plug assembly 100. The tubular body 12 does not need to be in a continuous piece as will be discussed in Figures 5A-5B.

[0060] Reference is made to Figure 2A. Figure 2A depicts an approximate cross-sectional view of the plug assembly 100 in a first position. The hole above side is at the top of the figure and the hole below side is at the bottom of the figure. The plug system 200 comprises a plug assembly 100 arranged in a tubular plug element 1. The tubular plug element 1 comprises a tubular body 12. The housing 11 is arranged in the tubular body 12.

[0061] A plug 2 is supported by a seat 4. A shear ring 5 is arranged to provide support to the seat 4. The ring of Petition 870220085558, dated 09 / 19 / 2022, page 31 / 70 / 33 shear comprises a shear ring body 51 and a shear ring rim 52. It is the rim of the shear ring 52 that is shown to support the seat 4 in the figure. The shear ring 5 is designed to shear (break) in the area between the rim of the shear ring 52 and the shear ring body 51. This causes the seat 4 and the stopper 2 to move downward in an axial direction.

[0062] Between seat 4 and plug 2 is arranged a bearing ring 22. This bearing ring 22 helps to hold plug 2 in place under high pressure. A bearing ring 22 may also be arranged on top of plug 2. (Note that bearing rings 22 are not labeled in Figures 2A-C, but are labeled in Figure 3B). Bearing rings 22 help to hold plug 2 in place under high pressure. If the pressure is higher from the hole below than from the hole above, plug 2 will be pressed against bearing ring 22 located in the hole above plug 2, whereas if the pressure is higher from the hole above than from the hole below, plug 2 will be pressed against bearing ring 22 located in the hole below plug 2. There is a sealing element 21 between plug 2 and housing 11. The purpose of the sealing element 21 is to help maintain the fluid seal of plug 2. It is preferable that plug 2 be fluid-tight between the first and second positions.Therefore, it is preferable that plug 2 be in sealing engagement with sealing element 21 in both the first and second positions. This also prevents fluid from circulating around plug 2 and causing it to twist or tilt. Furthermore, if the increase in differential pressure that would cause plug 2 to break is happening slowly and plug 2 is not in sealing engagement throughout the entire path between the first and second positions, this can lead to a pressure bleed and thus prevent a high enough differential pressure from breaking plug 2.

[0063] Seat 4 comprises a seat body 41. In the figure, a retaining ring 43 is arranged in a retaining ring groove 45 in the body. Petition 870220085558, dated 09 / 19 / 2022, page 32 / 70 / 33 of seat 41. Furthermore, the seat has a shredder pocket 44 that allows the shredder object 32 to pass through the seat during the operation of the buffer assembly 100. The retaining ring is designed in such a way that when the buffer assembly 100 is in the third position, it will expand into a retaining ring pocket 33 in the shredder assembly. In this way, the seat 4 will be prevented from moving hole up or hole down. In this embodiment, this prevention of any further movement of the seat 4 occurs because the seat 4 is locked in the shredder assembly 3 by the retaining ring 43. As the shredder assembly 3 is fixed in relation to the tubular body 12, this also fixes the seat 4 in relation to the tubular body 12. The seat 4 additionally comprises a retaining rim 42.The purpose of the retaining rim 42 is to prevent the shear ring rim 52 from moving axially and / or radially when the plug assembly 100 is in the third position. It is preferable that the retaining rim 42 extend at least the same distance as the thickness of the shear ring rim 52 to prevent the shear ring rim 52 from moving in a radial direction or twisting as the plug 2 moves axially. In this way, the chances of the shear ring rim 52 accidentally entering the wellbore are greatly reduced because it cannot move freely in an undesired direction during the operation of the plug assembly 100.

[0064] In the first position, as shown in Figure 2A, the shredding object 32 is not in contact with the cap 2. The shredding object 32 may be a pin, knife, or other suitable object for breaking the cap 2. The shredding object 32 is held in place by the shredder support 31. The shredder 3 further comprises a retaining ring pocket 33. The purpose of the retaining ring pocket 33 is to give the retaining ring 43 room to expand when in the third position.

[0065] The 100 buffer assembly additionally comprises a Petition 870220085558, dated 09 / 19 / 2022, page 33 / 70 / 33 retainer assembly 6. The retainer assembly 6 is fixed in relation to the tubular body 12. This allows the retainer assembly 6 to provide support to one or more elements in the buffer assembly 100. In Figure 2A, it provides direct support to the shear ring body 51 (and through the shear ring body 51, indirect support to the shredder support 31). The assembly retainer 6 is attached to the tubular body 12 by a retainer connector 62 arranged in the retainer body 61. The retainer connector 62 shown uses screws to attach the assembly retainer 6 to the housing 11 in the tubular body 12. Other options may include using a guide pin that is glued instead of screwed in, or using threads on the outside of the retainer connector 62 to screw into the housing 11. The threads may also be arranged on the outside of the retainer 6 itself (e.g., on the retainer body 61).Note that retainer 6 can also be attached to something that remains stationary relative to the tubular body 12.

[0066] The top of the retainer 63 is an area on top of the assembly retainer 6. In the third position, it is where the distal end of the retaining rim 42 comes into contact with the assembly retainer 6. This helps to prevent the shear ring rim 52 from moving axially and / or radially and entering the through hole of the tubular plug element.

[0067] A retainer assembly 6 can also be fixed to a stationary element relative to the seat 4 when the buffer assembly 100 moves from the second to the third position. For example, the tubular body 12 or an element that is supported by a projection of the tubular body 12, affixed to the tubular body 12 or indirectly supported by a stationary element relative to the tubular body 12.

[0068] Plug 2 is shown on the hole side above the plug assembly 100. However, it is also possible for plug 2 to be on the hole side below the plug assembly 100. This would allow the plug assembly 100 to be operated so that it is the pressure on the hole side below that Petition 870220085558, dated 09 / 19 / 2022, page 34 / 70 / 33 breaks the shear ring 5.

[0069] The seat is shown as being supported by the rim of the shear ring 52, however, it is also possible that the shredder assembly 3 is supported by the rim of the shear ring 52. This can be useful if the shredder object 32 itself moves to make contact with the buffer 2 and not with the seat.

[0070] The figures show that the retaining ring 43 is arranged in a groove of the retaining ring 45 in the seat body 41. However, the retaining ring 43 can also be arranged in the shredder support 31. In both cases, the retaining ring 43 would still prevent the seat 4 from moving in the axial direction in the third position. Furthermore, the retaining ring 43 can be arranged so that it expands (or contracts) in a groove in the tubular body 12 or other stationary element relative to the tubular body 12.

[0071] The retaining rim 42 is shown as a groove at the end of the seat body 41. However, the retaining rim 42 may be located elsewhere on the seat 4. What is important is that the retaining rim 42 fits around the shear ring rim 52 and prevents the shear ring rim 52 from moving axially when the buffer assembly 100 is in the third position. Preferably, the retaining rim 42 also prevents movement of the shear ring rim 52 in the radial direction as well. An advantage of not having the groove of the retaining rim 42, but along the seat body 41, is that the shear ring rim 52 can be closed on both sides. This would help to keep the shear ring rim 52 in place when in the third position.

[0072] Note that although the retaining ring pocket 33 is shown at the end of the shredder holder 31, this is not necessary. The retaining ring pocket 33 can be arranged in any Petition 870220085558, dated 09 / 19 / 2022, page 35 / 70 / 33 place along the shredder support 31, provided that the seat 4 can move sufficiently so that the buffer 2 breaks before or simultaneously with the buffer assembly 100 entering the third position.

[0073] Although it is preferable that the shear ring rim 52 be held in place while the seat 4 moves axially through the retaining rim 42, this is not essential.

[0074] In the case where the plug assembly 100 was inverted so that plug 2 was on the hole-down side of the plug assembly 100, the assembly retainer 6 could remain on the hole-down side or be moved hole-up. This would depend precisely on which elements needed the axial support provided by the assembly retainer 6.

[0075] Note that, as will be seen in Figures 5A-5B, the assembly retainer 6 is not essential. In this case, the shear ring 5 is supported by the first tubular section 15. Another example where the assembly retainer 6 is not essential is if the shear ring 5 is supported by a tubular body protrusion 12.

[0076] Reference is made to Figure 2B. Figure 2B depicts an approximate cross-sectional view of the buffer assembly 100 in a second position. As the buffer assembly 100 (and therefore the buffer system 200) moved from the first position to the second position, buffer 2 is in contact with the fragmenting object 32. This will initiate the process that will result in the breaking of buffer 2 and the flow of fluid through the tubular buffer element 1 being restored.

[0077] As seen in Figure 2B, the body of the shear ring 51 and the rim of the shear ring 52 have been cut. Since the seat was supported by the body of the shear ring 51, it is now free to move axially downwards. The rim of the shear ring 52 is prevented from moving radially into the wellbore by the retaining rim 42. The body of the shear ring 51 is being supported by Petition 870220085558, dated 09 / 19 / 2022, page 36 / 70 / 33 retainer assembly 6. The elastic ring 43 is arranged in the groove of the elastic ring 45.

[0078] Reference is made to Figure 2C. Figure 2C depicts an approximate cross-sectional view of the plug assembly in a third position. As shown in Figure 2C, plug 2 has broken (and is not seen in the figure) due to contact with the fragmenting object 32. Seat 4 will continue to move in an axial direction until snap ring 43 aligns with the snap ring pocket 33. At this point, snap ring 43 will expand into the snap ring pocket 33. This will prevent seat 4 from moving again in the axial direction. Additionally, the shear ring rim 52 will be trapped between the retaining rim 42 and the top of the retainer 63. This will further prevent the shear ring rim 52 from escaping into the wellbore through axial or radial movement.

[0079] In normal operation, the third position will be after the stopper 2 has been broken by the shredding object 32. However, it is possible for the second and third positions to occur simultaneously. In other words, the retaining ring 43 can be arranged in such a way that it locks the seat 4 and the shredder 3 together when the stopper 2 makes contact with the shredding object 32.

[0080] Reference is made to Figures 3A and 3B. Figures 3A and 3B describe an embodiment of the 200 plug system of a tubular plug element 1 and a plug assembly 100, shown in an exploded view and side view, respectively. The tubular plug element 1 comprises a tubular body 12 and opens upstream tubular connection 13 and downstream tubular connection 14. These are where other tubulars would be attached. Note that the tubular body 12 is made of one continuous piece in this figure. The plug assembly 100 is arranged within the tubular plug element 1 and comprises a plug 2, a shredder assembly 3, a seat 4, a shear ring 5, and an assembly retainer 6. The plug Petition 870220085558, dated 09 / 19 / 2022, page 37 / 70 / 33 rests on seat 4. Seat 4 is shown as arranged at least partially within the shredder assembly 3. Seat 4 is supported by a portion of the shear ring 5. The shear ring is supported by the assembly retainer 6. In the embodiment shown in the figure, a portion of the assembly retainer 6 is arranged within the shear ring 5.

[0081] A bearing ring 22 is arranged between the seat 4 and the cap 2. On the opposite side of the cap 2, a sealing element 21 is arranged between the cap 2 and a second bearing ring 22. The fragmenter 3 is composed of one or more fragmenter objects 32 and a fragmenter support 31. The seat 4 comprises a seat body 41. A retaining ring 43 is arranged in a retaining ring groove 45. A retaining rim 42 projects from the seat body 41. The purpose of the retaining ring is to lock the seat 4 in place in the third position. The retaining rim 42 prevents the shear ring rim 52 (not shown) from entering the wellbore when moving from the first position to the third position. The shear ring 5 comprises a shear ring body 51 and a shear ring rim 52 (not shown). The shear ring rim 52 is the portion of the shear ring 5 that supports the seat 4.The body of the shear ring 51 is supported by the retainer assembly 6. The top of the retainer 63 is a groove in the top part of the retainer body 61. The retainer is fixed to the housing 11 in the tubular body 12 by means of the retainer connector 62. In these figures it is fixed by screws and threads, where said threads coincide with threads in the tubular body 12 of the tubular plug element 1 and are screwed into it. During assembly, the screws are partially screwed into the tubular body 12, the retainer body 61 is then inserted into the tubular body 12 by screwing the retainer body 61 into the tubular body and the screws are then screwed completely into the tubular body 12.

[0082] Note that although the 100 buffer set that is inserted Petition 870220085558, dated 09 / 19 / 2022, page 38 / 70 / 33, in the tubular plug element 1, which is shown in all figures as comprising a pressure ring 43 and a retaining assembly 6, these elements are not required. Plug assemblies 100 without one or both elements may also be inserted into the tubular plug element 1.

[0083] Since Figures 3A and 3B are shown in an exploded view, these figures show an example of a method for assembling a 200 buffer system when the tubular body is a single continuous piece. The 100 buffer assembly is inserted into housing 11 in the tubular buffer element 1, then a retainer assembly 6 is inserted into housing 11 and secured thereto, resulting in retainer assembly 6 supporting the buffer assembly.

[0084] Preferably, the cap 2 is inserted into the tubular body 1 first. Then, the shredder assembly 3 and the seat 4 and shear ring 5 are fitted, with the seat 4 inside the shredder assembly 3 and the shear ring 5 on the hole side below the seat 4 and shredder assembly 3. Then, the assembled shredder assembly 3, seat 4 and shear ring 5 are inserted together into the tubular body 1. Alternatively, the cap 2 is inserted into the tubular body 1 first, followed by the shredder assembly 3, then the seat 4 is inserted into the shredder assembly 3, and finally the shear ring 5 is installed in the tubular body 1. In either case, the cap 2 will be arranged on top of the seat 4 and the seat 4 at least partially inside the shredder assembly 3.Since the shear ring 5 is inserted last, the other components rest on it, and thus the upstream pressure will be carried through the buffer 2 to the seat 4 up to the shear ring 5, and when the shear ring 5 breaks due to said pressure, the seat 4 will be released to move downwards. In some examples, the shredder assembly 3 may be inserted into the seat 4 instead. Petition 870220085558, dated 09 / 19 / 2022, pp. 39 / 70 / 33 otherwise.

[0085] By using a retainer assembly 6, it is possible for the buffer assembly 100 to be supported without the seat 4 and / or shredder assembly 3 and / or shear ring 5 supported on a second tubular section 16. One effect of this is that a manufacturer does not need to create protrusions of the inner diameter of the tubular body 12 to give the buffer assembly 100 a place to rest.

[0086] In another example, the buffer assembly 100 can be supported and fixed to the housing 11 by means of a fastening of the shear ring body 51 to the housing 11. One way to do this would be to use a two-part shear ring 5 where the shear ring body 51 is of a material strong enough to support the buffer assembly 100 during operation and using shear pins between the shear ring body 51 and the shear ring flange 52. Another way to achieve this is to support the shear ring 5 (or the assembly retainer 6) with a tubular body overhang 12.

[0087] Reference is made to Figures 4A-4D. Figures 4A-4D depict the buffer system 200 as it moves from a first to a third position. The buffer system 200 consists of a buffer assembly 100 arranged in a tubular buffer element 1. In the first position, as shown in Figure 4A, the buffer 2 is not in contact with the shredder object 32 of the shredder 3. The buffer 2 is supported by the seat 4. The seat 4 is supported by the shear ring 5 which is supported by the assembly retainer 6.

[0088] To move the buffer system 200 to the second position, as shown in Figure 4B, where buffer 2 is in contact with the fragmenting object 32, a predetermined threshold differential pressure is applied to buffer 2. This causes the shear ring 5 to shear. Since the portion of the shear ring 5 provided support to the seat 4, the seat 4 now does not Petition 870220085558, dated 09 / 19 / 2022, page 40 / 70 / 33 will be supported. Seat 4 will then move in an axial direction. This will place the buffer 2 in contact with the shredding object 32 of the shredder 3. Note that the shear ring 5 can be adjusted to shear at a predetermined absolute pressure applied to buffer 2.

[0089] Figure 4C shows an intermediate state between the second and third positions. The cap 2 has not yet broken and the fragmenting object 32 is now being forced further into the edge of the cap 2.

[0090] Figure 4D shows the third position. The cap 2 broke and the retaining ring 43 (not shown) in the seat 4 locks into a groove in the shredder assembly 3. This prevents the seat 4 from moving axially (hole up or hole down).

[0091] Reference is made to Figures 5A and 5B. Figures 5A and 5B describe an embodiment of the plug system 200 in which the tubular plug element 1 is made of two different tubular sections. In Figures 14D, the tubular plug element 1 is composed of a tubular body 12 which is a continuous piece. In this alternative, the tubular plug element 1 is constituted by a first tubular section 15 and a second tubular section 16 instead of a single piece. The upstream tubular connection 13 is at one end of the first tubular section 15 and the downstream tubular connection 14 is at the end of the second tubular section 16.

[0092] This example has almost the same buffer assembly 100 as the previous examples. However, in this example, a buffer assembly retainer is not present. Buffer 2 rests on seat 4. Seat 4 is supported by shear ring 5 (in particular, the shear ring rim 52). A shredder assembly 3 is arranged to break buffer 2 in the second position (when the buffer first contacts the shredder object 32), between the second and third positions, or in the third position.

[0093] In the previous examples, the body of the shear ring 51 Petition 870220085558, dated 09 / 19 / 2022, page 41 / 70 / 33 of the shear ring 5 was supported by the assembly retainer 6 (not shown). In this example, the shear ring body 51 is supported by the top of the second tubular section 16.

[0094] As in the previous examples, the retaining rim 42 is arranged so that the rim of the shear ring 52 cannot enter the wellbore through axial or radial movement. However, instead of the retaining rim 42 contacting the top of the retainer 63 (not shown), it makes contact with the second tubular section 16.

[0095] Note that it is possible to have a tubular plug element 1 that has a first tubular section 15 and a second tubular section 16 that still uses an assembly retainer 6. The assembly retainer 6 can, for example, be fixed to the tubular body 12 of the first tubular section 15 or the second tubular section 16. Another example is that the assembly retainer 6 can rest on top of the second tubular section 16. In the case of the plug assembly 100 being inverted relative to the figures, the assembly retainer 6 can be in contact with the first tubular section 15 instead of the second tubular section 16, as shown.

[0096] The pressure ring 43 is arranged to lock the seat 4 in place when the buffer assembly 100 moves to the third position. This occurs when the retaining ring 43 arranged in the seat enters the pocket of the retaining ring 33 in the shredder assembly 3.

[0097] Reference is made to Figure 6. Figure 6 describes an embodiment of the retainer 6 with a retainer damper 64. The retainer assembly 6 may also further comprise a retainer damper 64. This is a damping mechanism that would provide shock absorption when the buffer assembly 100 is moving from a first position to the second and third positions. If there is a high differential pressure, the seat 4 may be moving with a considerable amount of speed and force. It is conceivable that if the force is Petition 870220085558, dated 09 / 19 / 2022, page 42 / 70 / 33 sufficiently high, the impact may make it difficult for the retaining ring 43 to lock in place and not break. Another possible problem with high-force movement is that the components of the buffer assembly 100 (e.g., seat 4) may dislodge the retaining assembly 6 itself. A retaining damper 64 will absorb some of this force and help protect against failure of the components of the buffer assembly 100. This can be done by making a portion of the top of the retainer out of a shock-absorbing material (such as rubber). Another way to do this is to make a portion of the top of the retainer movable, but in a damped manner. For example, using mechanical springs, fluid springs (such as oil chambers), pistons, or sealed chambers.

[0098] Reference is made to Figures 7A-7C. Figures 7A-7C describe an embodiment of the assembly retainer 6 which is composed of retainer segments 65. The retainer segments 65 allow the assembly retainer 6 to be inserted as separate parts and then secured. The retainer segments 65 in Figure 7A show retaining projections 66 in the radial direction of the retaining body 61. The retaining projections 66 allow the tubular body 12 to provide support for the retainer segments 65. In the specific case of Figure 7A, there are two segments 65A, 65B. These retainer segments 65 are held in place by a retainer ring 67. The retainer ring 67 is secured directly or indirectly to the tubular body 12. The retaining projections 66 fit into corresponding grooves in the housing 11 in the tubular body 12.

[0099] Figure 7B depicts one of the Retainer Segments 65 in a perspective view. As discussed above, there are retaining projections 66 that extend outward in a radial direction from the retaining body 61.

[00100] Figure 7C depicts a retainer assembly 6 with three retainer segments 65A, 65B, 65C.

[00101] Instead of using a retainer ring 67, the Segments of Petition 870220085558, dated 09 / 19 / 2022, p. 43 / 70 / 33 Retainer 65 can be attached directly to the tubular body 12. Note that the Retainer Segments shown in Figures 7A-7C have a protrusion that extends to the center of the tubular plug element 1. While this is not necessary for the functioning of this embodiment of the retainer assembly 6, it allows for easier alignment of the retainer ring 67 during assembly. Furthermore, this allows the retainer ring 67 to provide more support to the retainer assembly 6.

[00102] Figure 7C shows a top view of a retainer assembly 6 comprising three retainer segments 65A, 65B, 65C. This is an illustrative example. There may be two or more Retainer Segments 65 used. Note also that the Retainer Segments 65 are shown as abutting each other to form a complete ring. There may be gaps between one or more of the Retainer Segments 65. This may be necessary to facilitate the assembly of the tubular plug element 1 because there will be more space to place the Retainer Segments 65 in position. Note that three Retainer Segments 65 are the most preferable arrangement as this allows the fewest number of Retainer Segments 65 to be installed without any gaps between them. This provides the best support with the fewest number of individual parts that must be manufactured and assembled.

[00103] The Retainer Segments 65 configuration is shown with retaining protrusions 66. However, depending on the tolerances required or the support strength provided by the retainer ring 67, it may be possible to have no retaining protrusions 66. The figures are shown with four retaining protrusions 67, but the number of retaining protrusions can be adjusted depending on the need.

[00104] The retainer ring 67 is shown as fixed to the tubular body 12 with an adjusting screw. One skilled in the art would know other ways of achieving such a fixation. Another option is to use a locking ring that can expand into a groove in the tubular body 12 to hold the ring. Petition 870220085558, dated 09 / 19 / 2022, page 44 / 70 / 33 of retainer 67 in place. This may be a separate element or a part of the retainer 67 ring.

[00105] In the figures shown, the housing 11 is a portion of the tubular body 12 that has been shaped (e.g., milled or cast) to receive the plug assembly 100. In this case, the attachment to the housing 11 is the same as the direct attachment to the tubular body 12. This is also true in the case where the housing 11 is a separate element and the retainer 6 is attached to a portion of the housing 11 that is stationary relative to the tubular body 12 when the plug assembly 100 is in the first or second position.

[00106] As discussed in this document, the shear ring 5 generally has a shear ring body 51 and a shear ring rim 52. In the figures, this shear ring rim 52 is shown to be thinner than the shear ring body 51. This need not be the case; it may be the same thickness or thicker than the shear ring body 51. The shear ring rim 52 also need not be located at the end of the shear ring body 51, forming an L shape, but may be located anywhere along the shear ring body 51 and have any suitable shape. The shear ring rim 52 may optionally be divided into shear ring tabs. These tabs are portions where the shear ring rim 52 has been divided into several pieces.The shear ring 5 can be easily adjusted to a desired shear pressure, for example, by adjusting its material type, thickness, or number of shear tabs. The shear values ​​are predictable and repeatable. Thus, the assembly can be pre-set to open at a defined value by changing only the shear ring 5. Instead of a shear ring 5, it is also possible to alternatively use shear pins according to the present invention. Instead of having a ring shape, they have a pin shape, and 2 or more pins can be used. Petition 870220085558, dated 09 / 19 / 2022, page 45 / 70 / 33 shear around the circumference of the cap seat 4, preventing it from moving in an axial direction exactly as a shear ring 5 would.

[00107] Preferably, the sealing element of the plug 21 is in contact with the housing 11. If the sealing element is between the housing 11 and the plug 12, the plug 12 and the sealing element 21 effectively form a fluid-tight seal in the housing 11. More preferably, the sealing element 21 is an O-ring located around the circumference of the plug 2, sealing it against the interior of the tubular body 12 in which it is installed, but other forms of sealing may also be used.

[00108] The buffer is preferably a frangible disc, which is most preferably made of one or more layers of glass. The glass does not visibly change or become damaged by corrosive conditions or high temperatures in a pit and has the advantage of being able to break into very small pieces. Different types of glass can be obtained with different strengths and thicknesses capable of withstanding the differential pressures to which the buffer assembly may be subjected. In some cases, for example, when a very strong and / or thick glass is desired, it may be preferable to use two or more layers of glass. The production of specially hardened glass that is very thick is not feasible, and several thinner layers may be stronger than one thick layer. The buffer assembly 100 presented here can be used with a glass pack made of a single layer of glass or a plurality of stacked layers.The glass layers can be stacked directly on top of each other, or with a thin film of damping material between them, to ensure sufficient force distribution in case the disc surfaces are not sufficiently flat.

[00109] The retaining ring can be arranged in the first position in Petition 870220085558, dated 09 / 19 / 2022, page 46 / 70 / 33 retaining ring groove or in a retaining ring cavity in the shredder holder and then fit into the retaining ring cavity or retaining ring groove when the assembly moves from the first position to the third position.

[00110] In one example, the shear ring additionally includes a shear ring body and a shear ring rim; wherein: the shear ring cuts at an interface between the shear ring rim and the shear ring body; the seat additionally includes a retaining rim, wherein the retaining rim is arranged so as to prevent the shear ring rim from moving in an axial and / or radial direction in the third position. This prevents shear and therefore not attached to the shear ring rim of the assembly from entering the wellbore.

[00111] The plug assembly must be supported, not loose in the tubing. Having an assembly retainer fulfills this need. Alternatively, this could be done by a crossover, i.e., having the tubing composed of two sections, where the second section would support and hold the plug assembly parts in place. This is how this type of plug assembly is usually supported and constructed, adding the assembly components to one section of tubing and then holding everything in place by adding a second tubular section. The addition of a retainer makes it possible to have only one tubular section and no crossover. In some applications, such as under high pressure and / or temperature conditions, this is quite desirable, as there is always the possibility of a fluid leak when two tubular sections are joined, i.e., fluid leakage between the annulus and the wellbore. Thus, additional welds and seals are avoided.

[00112] In one example, the assembly retainer additionally includes a retainer connector and wherein the retainer connector secures the retainer to Petition 870220085558, dated 09 / 19 / 2022, p. 47 / 70 / 33 assembly to the housing. The housing is the portion of the tubular structure that accommodates the plug assembly, or it may also refer to a separate element with this function installed in the tubular structure. The retainer connector may, for example, be screws or pins or threads on the outside of the retainer that you screw into the receiving threads on the tubular structure. Preferably, for greater safety, a combination of retainer connectors is used, for example, both the threads on the retainer and the tubular structure as the primary means of securing the retainer to the tubular structure and then screws as a safety feature. In this preferred example, the screws would prevent the retainer from vibrating loose if the tubular structure is subjected to too much vibration during installation in the well and thus will lock the retainer in place once it is screwed into the tubular structure.

[00113] Examples of configurations in which the plug 2 does not move are found in Figures 8A-10B. Note that the examples of systems and elements provided below can be combined with those discussed previously. For these examples, the first position is where the plug is intact and there is no fluid flow through the tubular plug element 1, and a second position where there is fluid flow through the tubular plug element 1. The main difference between these examples is that the plug 2 or the fragmenting object 32 do not need to move relative to each other. The fragmenting object 32 refers to the portion of the plug assembly 100 that causes the plug 2 to break when desired. This fragmenting object 32 can be a seat 4, a portion of the tubular body 12, a bearing ring 22, an explosive, or another element that breaks the plug 2.

[00114] The plug does not need to move relative to the fragmenter. This can be done using an explosive. The explosive is then installed so that when it explodes, it breaks the plug. The explosive thus acts as a fragmenter. Another example of breaking the frangible plug in place is simply applying sufficient pressure from the wellhead to cause the plug to break against an element with which it is in contact. This Petition 870220085558, dated 09 / 19 / 2022, page 48 / 70 / 33. The element then acts as a shredder, but without it and the buffer moving to come into contact with each other. Instead, the element and the buffer start in contact, and the increase in pressure causes the buffer to break against the element without relative movement. The buffer will then rest on the element and break against it. The amount of differential pressure required for breakage can be adjusted by adjusting the buffer (e.g., making it thinner or of a material that breaks more easily if less pressure is desired) and / or the element against which it breaks (e.g., making the element in a shape that decreases the contact area, as described above for shredders that move relative to the buffer if less pressure is desired). Note that the element can simply be the part of the box wall against which the buffer rests.

[00115] Reference is made to Figure 8A and Figure 8B. Figures 8A and 8B depict an example similar to that described previously, except that there is no shear ring 5 and the buffer 2 does not move relative to the shredding object 32 when moving from a first position to a second position. In this example, the assembly retainer 6 holds the seat 4 in place. The housing 11 of the buffer assembly 100 is arranged in a tubular body 12. The tubular body 12 is a single continuous piece (although the buffer assembly 100 does not require this this time). In this case, the shredding object 32 is a portion of the seat 4. Pressure can be used to apply sufficient pressure to force the buffer 2 into the seat 4 with enough force to cause it to break. Furthermore, the pressure can be high enough to simply exceed the buffer's strength and cause it to break. One advantage of this is that there are fewer moving parts compared to using a shear ring and moving the plug.

[00116] Note that although seat 4 is shown as a separate element from assembly retainer 6, it would be possible for seat 4 to be Petition 870220085558, dated 19 / 09 / 2022, p. 49 / 70 / 33 integrated into the assembly retainer 6. Although these two figures show a bearing ring 22, as will be shown later, this is not an essential element. The assembly retainer 6 is of the same type described above.

[00117] Reference is made to Figure 9. Figure 9 describes an example where a plug 2 is supported in a space at the top of a second tubular section 16 which is inside a first tubular section 15. In this case, there is no seat 4 or assembly retainer 6. In this case, the fragmenting object 32 will be a portion of the second tubular section 16.

[00118] Reference is made to Figures 10A and 10B. Figures 10A-10B depict an explosive as a fragmenting object 32. In the case of Figure 10A, this explosive is outside the cap 2 (preferably in contact with it). In the case of Figure 10B, the explosive is inside the cap 2 itself.

[00119] Note that the explosive may be part of an embodiment that uses an assembly retainer 6 and / or a tubular body 12 that is a single continuous piece. The explosive may also be part of a system in which the plug rests directly on the tubular body 12 or on a seat 4.

[00120] Note that “step of” should not be interpreted as “step to”. By “composed of”, “comprising”, “comprises”, etc., we are referring to an open set, and by “consisting of” we are referring to a closed set.

[00121] Modifications to the embodiments described above are possible without departing from the scope of the invention, as defined by the appended claims. The numerals included in parentheses in the appended claims are intended to aid understanding of the claims and should not be construed in any way to limit the subject matter claimed. Reference to the singular should also be interpreted as relating to the plural, unless expressly indicated otherwise. Any reference numbers in the claims are provided as a courtesy and should not be construed as limiting the claim in any way.

Claims

1. Plugging system (200), characterized in that it comprises: a tubular plugging element (1) comprising a tubular body (12), an upstream tubular connection and a downstream tubular connection; wherein: the upstream tubular connection and the downstream tubular connection are openings at opposite ends of the tubular body (12); and a plugging assembly arranged in a housing (11) comprising: a plug (2); a shredding object (32); and a seat (4); wherein: the plug (2) is supported by the seat (4); the plugging assembly has a first position and a second position; wherein in the first position, the plug (2) is not in contact with the shredding object (32); and in the second position the plug (2) is in contact with the shredding object (32); wherein: there is a fluid connection between the upstream tubular connection and the downstream tubular connection; and the tubular body (12) is a single continuous piece;and wherein the buffer assembly is entirely arranged within the tubular buffer element (12).; 2. Buffer system (200) according to claim 1, characterized in that the buffer assembly further comprises an assembly retainer (6) arranged to support the buffer assembly, and the assembly retainer (6) is stationary relative to the housing, wherein the assembly retainer (6) is a separate element from the tubular body (12).

3. Buffer system (200) according to claim 2, characterized in that the assembly retainer (6) comprises threads for securing the assembly retainer (6) to the housing (11).

4. Buffer system (200) according to claim 2, characterized in that the assembly retainer (6) further comprises a plurality of retainer segments (65).

5. Buffer system (200) according to claim 4, characterized in that at least one of the plurality of retainer segments (65) comprises a retainer body (61) and a retainer protrusion (66), wherein the retainer protrusion (66) extends from the retainer body (61) in a radial direction.

6. Buffer system (200) according to claim 4, characterized in that the buffer assembly further comprises a retainer ring (67) arranged to secure the retainer segments (65) to the housing (11), wherein at least a portion of the retainer body (61) is arranged between the housing (11) and a portion of the retainer ring (67).

7. Buffer system (200) according to claim 1, characterized in that the buffer assembly further comprises a shear ring (5), wherein the shear ring (5) is arranged such that, when a limit pressure differential is applied to a buffer surface (2), the shear ring (5) breaks and permits axial movement of the seat (4).

8. Buffer system (200) according to claim 7, characterized in that the assembly retainer (6) supports the shear ring (5). Petition 870260012220, dated 09 / 02 / 2026, page 13 / 41 3 / 3 9. Buffer system (200) according to claim 7, characterized in that the shear ring further comprises a shear ring body (51) and a shear ring rim (52), wherein the shear ring rim (52) supports the seat (4) in the first position, the shear ring (5) being arranged to shear between the shear ring rim (52) and the shear ring body (51) when the buffer assembly moves from the first to the second position; and wherein the seat (4) further comprises a retaining rim (42), wherein the retaining rim (42) is arranged so as to prevent the shear ring rim (52) from moving in an axial and / or radial direction when in the second position.

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