Fracking plug with a foam loading member

Abstract

An example plug assembly includes: a cone (108); an anchoring ring (112) mounted to the cone and comprising a plurality of segments (300) disposed in a circular array; and a foam member (114) that is radially interposed between the cone and the anchoring ring, wherein the foam member comprises a base material (602) and gas bubbles formed therein, wherein during deployment of the plug assembly, the cone is driven in a distal direction, thereby expanding the anchoring ring as the foam member is compressed between the cone and the anchoring ring.

Description

Fracking Plug with a Foam Loading MemberCROSS REFERENCE TO RELATED APPLICATION

[0001] The present application claims priority to U.S. Provisional Patent Application No.63 / 789,902, filed on April 16, 2025, the entire contents of which are herein incorporated by reference as if fully set forth in this description.BACKGROUND

[0002] Fracking is a well stimulation technique that involves the fracturing of formations in bedrock by a pressurized liquid. The process involves the high-pressure injection of “fracking fluid’7into a wellbore to create cracks in the deep-rock formations through which natural gas, petroleum, and brine can flow more freely.

[0003] In fracking applications, a plug can be used to seal and isolate certain portions of a drilled well from other portions of the well. A sealing plug that fully isolates one well portion (e.g., a downstream or down hole portion) from another well portion (e.g., an upstream or up hole portion), wholly blocking flow between the two portions, can be referred to as a bridge plug. Other types of plugs may allow flow' in a particular direction (e.g., downstream), but block flow' in other directions (e.g., upstream). Plug seals may be permanent, or may be nonpermanent dissolving or otherwise removable plugs.

[0004] For example, a bridge plug may be located within a well casing to isolate a downstream portion of a well from an upstream portion of the well. In the upstream portion, the well casing may include a plurality of transverse holes that open into a surrounding rock formation. In the hydraulic fracturing process, pressurized fluid is pumped down into the well. At the bridge plug, flow of such fluid is blocked from proceeding from the upstream portion to the downstream portion, thereby causing the upstream portion of the well to be pressurized. Under such pressure, the fluid is forced through holes in the upstream well casing into the adjacentrock formation. The pressurized flow into the rock formation in turn creates cracks through which oil and gas may be extracted.

[0005] The plug is typically anchored in place via a particular component. For example, the plug may be segmented, and the segments may having anchoring features that allow them to remain attached to the well casing when pushed into the well casing. Typically, a setting tool is attached to the plug, and then both the tool and the plug are driven to a particular desired position within the well casing, and the plug is then expanded to be anchored in position to the well casing or pipe.

[0006] However, in some cases, the interior surface of the well casing might not be perfectly circular, but may rather be distorted or out-of-roundness. For instance, the interior surface may have an oval or irregular shape. In these cases, while the setting tool may push some segments of the plug into the well casing (at portions of the casing having smaller inner diameter), other segments might not be properly anchored into the well casing (at portions of the casing having larger inner diameter).

[0007] The segments that are not properly anchored may be somewhat loose. Under high pressure from fluid, such segments may be dislodged, leading to loss of anchoring and failure of the plug, thereby allowing fluid to leak through the plug.

[0008] It may thus be desirable to configure the plug in a manner that reduces or eliminates the likelihood of loss of anchoring of the plug in such conditions. It is with respect to these and other considerations that the disclosure made herein is presented.SUMMARY

[0009] The present disclosure describes implementations that relate to a fracking plug with a foam loading member.

[0010] In a first example implementation, this disclosure describes a plug assembly including: a cone; an anchoring ring mounted to the cone and comprising a plurality of segments disposed in a circular array; and a foam member that is radially interposed between the cone and the anchoring ring, wherein the foam member comprises a base material and gas bubbles formed therein, wherein during deployment of the plug assembly, the cone is driven in a distal direction, thereby expanding the anchoring ring as the foam member is compressed between the cone and the anchoring ring.

[0011] In a second example implementation, this disclosure describes a method of deploying the plug assembly of the first example implementation in a tube.

[0012] In a third example implementation, this disclosure describes a system including a tube, the plug assembly of the first example implementation, and a tool for deploying the plug assembly into the tube.

[0013] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, implementations, and features described above, further aspects, implementations, and features will become apparent by reference to the figures and the following detailed description.BRIEF DESCRIPTION OF THE FIGURES

[0014] The novel features believed characteristic of the illustrative examples are set forth in the appended claims. The illustrative examples, however, as well as a preferred mode of use, further objectives and descriptions thereof, will best be understood by reference to the following detailed description of an illustrative example of the present disclosure when read in conjunction with the accompanying Figures.

[0015] Figure 1 A illustrates a system having a plug assembly disposed within a tube via a tool, according to an example implementation.

[0016] Figure IB illustrates a perspective cross-sectional view of the plug assembly of Figure 1 A positioned within the tube, according to an example implementation.

[0017] Figure 1C illustrates a side view of a cone of the plug assembly of Figures 1A-1B with a foam member mounted thereto, according to an example implementation.

[0018] Figure 2A illustrates a cross-sectional side view of the plug assembly of Figures 1A-1B in a deployed state, according to an example implementation.

[0019] Figure 2B illustrates a perspective cross-sectional view of the plug assembly of Figures 1 A- IB in the deployed state, according to an example implementation.

[0020] Figure 3A illustrates a perspective top view of a segment of a plurality of segments of an anchoring ring of the plug assembly, according to an example implementation.

[0021] Figure 3B illustrates a perspective bottom view of the segment of Figure 3A, according to an example implementation.

[0022] Figure 4 illustrates a perspective view of a seal of the plug assembly, according to an example implementation.

[0023] Figure 5A illustrates a partial distal view of the plug assembly within a tube having a circular interior surface, according to an example implementation.

[0024] Figure 5B illustrates a partial distal view of the plug assembly within a tube having an oval-shaped interior surface, according to an example implementation.

[0025] Figure 6 illustrates an image captured via scanning electron microscopy of a syntactic foam, according to an example implementation.

[0026] Figure 7 is a graph showing multi-modal force-position characteristics of a foam member of the plug assembly, according to an example implementation.

[0027] Figure 8 is an image taken after a test involving deploying the plug assembly in a tube having an inconsistent inner diameter, according to an example implementation.

[0028] Figure 9 is a graph showing varying multi-modal characteristics of the foam member based on material choice and volume fraction of particles in a base material of the foam member, according to an example implementation.

[0029] Figure 10 is a flowchart of a method for deploying a plug assembly in a tube, according to an example implementation.DETAILED DESCRIPTION

[0030] In examples, a fracking plug needs to be anchored firmly in place within well casing (steel tubing) and needs to seal fluid under pressures that can exceed 10,000 pounds per square inch (psi) to effectively isolate one section of a well casing from another. Within examples, the anchoring function and the sealing function are both activated by expanding a ring over a cone using a hydraulic setting tool that is capable of generating many tons of force. Particularly, an elastomeric ring-shaped seal is expanded over the cone during deployment of the plug to facilitate sealing against the interior surface of the well casing.

[0031] The anchoring function can be provided by a segmented anchoring ring, and the segments of such anchoring ring are expanded radially outw ard by the cone in unison with the seal. The segments come into contact with the well casing and drive anchoring features (e.g., teeth with sharp edges) into the casing creating depressions. It is desirable for the segments to remain engaged with the well casing depressions to firmly hold position. This way, the segments remain locked to the casing, and support is provided through the shear resistance of the high strength casing steel, and not just through surface friction between the segments and well casing.

[0032] However, in some examples, due to imperfections or distortions in the interior surface of the well casing, the interior surface might not be perfectly circular (e.g., might be out-of-roundness). Rather, the interior surface may have an irregular shape, e.g., an oval shape, such that some portions have larger inner diameters than others.

[0033] In these examples, when the hydraulic setting tool causes the segmented anchoring rings to expand, some segments at the smaller inner diameter portions may contact the well casing first and are driven hard into to the well casing, while other segments at the larger inner diameter portions might not be properly anchored into the w ell casing. In other w ords, thesegments that contact the well casing first “steal” most of the load being applied to them from other segments. As such, the segments that are not properly anchored may be somewhat loose and may be dislodged (e.g., disengage from the well casing) under fluid pressure, leading to plug failure and leakage.

[0034] Disclosed herein are systems, assemblies, and methods associated with a plug assembly having a foam member (a foam loading member) radially interposed between the cone and the segmented anchoring ring. For example, the foam member may be made of a syntactic or metallic foam material include a metallic or polymeric base (matrix) material with gas bubbles formed therein. The bubbles may be formed by particles (e.g., ceramic or glass thin-walled hollow spheres) suspended in the base material.

[0035] The foam member has a multi-modal stress / strain curve characteristics in compression. Particularly, when a force is applied to the foam member via the cone as the cone is driven by the setting tool, the initial compression of the foam member elicits an elastic behavior typically found in a solid material.

[0036] Once the force or stress reaches a threshold value (specific for the particular material and type of particles of the foam loading member), the foam member enters a plateau region where the force / stress may remain substantially the same for a wide range of deformation (strain). In other words, the material keeps geting compressed without requiring additional load. In such plateau region, the material readily compresses or “collapses” due to the crushing of gas bubbles, while still possessing some degree of elastic recovery.

[0037] Thus, while some segments of the segmented anchoring ring reach the well casing first if the well casing is not perfectly circular, the foam member may be locally crushed adjacent to the minor diameter of the casing, thereby allowing the other segments of the anchoring ring to continue moving toward the well casing. With this configuration, all the segments areallowed to be properly anchored into the well casing even at portions of the well casing having larger inner diameters.

[0038] As load on the foam member continues to increase, the plateau region ends, and thereafter an additional load is required to keep compressing the foam member. Once the load is removed, the foam member partially elastically recovers, which maintains load on the segments of the anchoring ring.

[0039] The multi-modal characteristics of the foam member is adjustable through choice of raw materials and volume fraction of gas bubbles inside a matrix (e.g., base) material. The foam member can also be configured to have adjustable geometry (e.g., have different geometric shapes or features such as grooves, different slopes, etc.), which alters contact areas as collapsing occurs to tune its behavior.

[0040] Figure 1 A illustrates a system 100 having a plug assembly 102 disposed within a tube 104 via a tool 106, and Figure IB illustrates a perspective cross-sectional view of the plug assembly 102 positioned within the tube 104, according to an example implementation. Figures 1 A-1B show the plug assembly 102 in a pre-assembled state or during deployment of the plug assembly 102. The tube 104 represents a well casing in a fracking application and can be made of high strength steel, for example.

[0041] The tool 106 can be a hydraulic setting tool that is attached to the plug assembly 102, and then both the tool 106 and the plug assembly 102 are pushed (e.g., via water or any fluid) down the tube 104 to a particular position within the tube 104. The tool 106 is depicted in a simplified manner in Figure 1A and is shown as being separate from the plug assembly 102. However, it should be understood that during conveyance of the plug assembly 102 to a particular location within the tube 104, the tool 106 is attached to the plug assembly 102. After activation and anchoring of the plug assembly 102 to the tube 104 at the particular location,the tool 106 is decoupled (e.g., via shear features) and is pulled away from the plug assembly 102.

[0042] The plug assembly 102 includes a cone 108, a seal 110, an anchoring ring 112, and a foam member 114. As shown in Figure 1 B, the anchoring ring 112 is segmented. In examples, an end plate (not shown) is mounted to a distal end of the anchoring ring 112 to keep the segments together during deployment of the plug assembly 102. Such end plate can be bonded (e.g., via an adhesive) to the anchoring ring 112, for example. Prior to deployment, the outer diameter of the anchoring nng 112 is smaller than an inner diameter of the tube 104 as shown in Figures 1A-1B. The foam member 114 can be molded onto or bonded to either / both the cone 108 or the anchoring 112.

[0043] Figure 1C illustrates a side view of the cone 108 with the foam member 114 mounted thereto, according to an example implementation. As show n, the foam member 114 is generally conical in shape and is hollow such that it can be mounted (e.g., radially interposed) between the cone 108 and the anchoring ring 112. In other example implementations, however, the foam member 114 may rather be mounted within (e.g., bonded to) the anchoring ring 112 during deployment.

[0044] Referring back to Figures 1A-1B, to deploy the plug assembly 102 within the tube 104, the tool 106 and the plug assembly 102 are driven down the tube 104 until the plug assembly 102 reaches a desired position. The tool 106 is then used to apply a large force (e.g., up to 20,000 pound-force) to insert the cone 108 into the seal 110 and the anchoring ring 112 (which is segmented as shown in Figure IB), causing them to expand against an interior peripheral surface of the tube 104. Under such force and expansion of the anchoring ring 112. the abovementioned end plate can shear off. leaving the anchoring ring 112 in position.

[0045] Figure 2Aillustrates the plug assembly 102 in a deployed state, and Figure 2B illustrates a perspective cross-sectional view of the plug assembly 102 in the deployed state, according to an example implementation. In the deployed state, the foam member 114 is radially interposed between the cone 108 and the anchoring ring 112 as shown.

[0046] The cone 108 can have a cavity 116 (e.g., semi-spherical cavity) at its proximal end as shown in Figures 1 A-1B. After the tool 106 is withdrawn, a ball 200 can be dropped into the tube 104 and is driven into the cavity 116 to seal the cone 108 and prevent fluid flow through the cone 108 (which may be hollow or may have a channel therein). The seal 110 is configured to seal against the interior peripheral surface of the tube 104. With this configuration, the plug assembly 102 seals or isolates a upstream portion (proximal direction) of the tube 104 having high pressure fluid from a downstream portion (distal direction) of the tube 104.

[0047] Reference to “distal” and “proximal” herein is not intended to imply a specific orientation of components of the plug assembly 102 relative to any surrounding environment. Instead, these directional terms are intended to facilitate a description of the interrelationship between the several components of the plug assembly 102 and their function.

[0048] As mentioned above, the anchoring ring 112 is segmented. Particularly, the anchoring ring 112 includes a plurality of segments disposed in a circular array, and such segments are expanded upon deployment to be anchored to the wall of the tube 104.

[0049] Figure 3 A illustrates a perspective top view7of a segment 300 of a plurality of segments of the anchoring ring 112, and Figure 3B illustrates a perspective bottom view of the segment 300, according to an example implementation. The segment 300 (and the other segments of the anchoring ring 112) has a tapered interior surface 302 that interfaces with the foam member 114 and the tapered portion of the cone 108. This way, as the cone 108, along with the foam member 114, are driven into the anchoring ring 112, the anchoring ring 112 expands. As such,longitudinal or axial movement of the cone 108 in the distal direction, causes the segments of the anchoring ring 112 to separate from each other and move radially outward, toward the interior peripheral surface of the tube 104.

[0050] The segment 300 includes one or more anchoring feature(s) 304 disposed on its exterior surface that facilitate affixing the segment 300 of the anchoring ring 112 to the tube 104. The anchoring feature(s) 304 can be teeth, serrations, barbs, wickers, buttons, or posts as examples. For instance, as depicted in Figures 3A-3B, the anchoring feature(s) 304 can include teeth with sharp edges that are driven into the interior surface or wall of the tube 104, creating depressions in the tube 104, as the anchoring ring 112 expands (due to distal movement of the cone 108 within, and its interaction with, the tapered surfaces of the segments).

[0051] This way, the anchoring ring 112 remains locked to the tube 104, and support is provided through the shear resistance of the high strength steel of the tube 104, and not just through surface friction between the segments (e.g., the segment 300) and the tube 104. As such, the anchoring ring 112 can also be referred to as a slip ring or slip-prevention ring, and the individual segments can be referred to as the slips.

[0052] The seal 110 is mounted to the distal portion of the cone 108 and interfaces with a proximal end of the anchoring ring 112. For example, the seal 110 interfaces with a proximal end face 306 of the segment 300.

[0053] Figure 4 illustrates a perspective view of the seal 110, according to an example implementation. The seal 110 can be configured as a radial seal made of an elastomeric material, for example. The seal 110 is ring shaped as depicted and has an interior peripheral surface 400 that interfaces with the exterior conical surface of the cone 108. The seal 110 also has a distal end face 402 that interfaces with the proximal end face of the segments (e.g., the proximal end face 306 of the segment 300) of the anchoring ring 112.

[0054] As mentioned above, the tool 106 is used to activate the plug assembly 102 and anchor it in a sealing position within the tube 104 once the plug assembly 102 and the tool 106 reach a particular desired location within the tube 104. In an example, the tool 106 can have a rod that passes through the plug assembly 102 and is attached to the end plate (not show n) mounted to the anchoring ring 112 via a decoupling feature (e.g., a shear feature). In this example, the plug assembly 102 can be referred to as having a “bottom sef' configuration due to the decoupling feature being oriented on the downstream or distal end of the plug assembly 102.

[0055] The tool 106 can also have a setting collar. To activate the plug assembly 102 once it reaches the desired location, the rod of the tool 106 holds the end plate in position while the setting collar pushes on the cone 108 to move in the distal direction. This puts the rod in tension. As such, the cone 108 and the foam member 114 mounted thereto are pushed in the distal direction into the seal 110 and the segments of the anchoring ring 112. The tapered surface of the tapered distal portion of the cone 108 interacts with the tapered surfaces (e.g., the tapered interior surface 302) of the segments of the anchoring ring 112. causing the anchoring ring 112 to expand, contacting the interior peripheral surface of the tube 104 to be anchored thereto (e.g., via the anchoring feature(s) 304).

[0056] Also, the distal portion (which is tapered) of the cone 108 interacts with the interior peripheral surface 400 of the seal 110 as the cone 108 is being driven by the tool 106 in the distal direction, causing the seal 110 to expand and seal against the interior peripheral surface of the tube 104.

[0057] It is desirable for the segments of the anchoring ring 112 to remain engaged with the tube 104 and not be dislodged under high pressure fluid forces. However, due to imperfections or lack of perfect circularity of the interior surface of the tube 104, some segments of the anchoring ring 112 may be driven properly into the wall of the tube 104, while other segmentsmight not, increasing the likelihood that some segments might be dislodged, leading to failure of the plug assembly 102.

[0058] Figure 5 A illustrates a partial distal view of the plug assembly 102 within the tube 104 having a circular interior surface, according to an example implementation. In Figure 5 A, the tube 104 has a perfectly round interior surface. Thus, as the cone 108 is driven into the anchoring ring 112 and the segments are pushed radially outward into the wall of the tube 104, the segments remain symmetric with respect to the cone 108, and are driven synchronously into the wall of the tube 104. The segments may thus be anchored properly to the tube 104 and are each subject to a similar share of the load. However, if the tube 104 does not have a perfectly round / circular interior surface, at least some of the segments might remain loose.

[0059] Figure 5B illustrates a partial distal view of the plug assembly 102 within the tube 104 having an oval-shaped interior surface, according to an example implementation. For example, the tube 104 may be 180 thousandth of an inch out-of-roundness. An oval-shaped interior surface is used herein as an example. Any other irregular shape that causes a variable distance between a center of the tube 104 and different portions along its interior surface is contemplated.

[0060] Due to the oval shape of the tube 104, it has a minor (smaller) inner diameter and a major (larger) inner diameter. Thus, as the cone 108 is driven into the anchoring ring 112, a first subset of segments such as segment 500 and segment 502 of the anchoring ring 112 that are on or close to the minor inner diameter portion of the tube 104 are driven properly into the wall of the tube 104 and are well-anchored thereto.

[0061] On the other hand, without the foam member 114, a second subset of segments such as segment 504 and segment 506 that are on or close to the major inner diameter, might not be driven sufficiently into the wall of the tube 104, and may thus remain loose and fail to beanchored properly to the tube 104. In other words, the segments close to the minor inner diameter may “steal” most of the load applied to the anchoring ring 112.

[0062] The foam member 114, however, is configured to make up for such distortion in the interior surface of the tube 104 and facilitate pushing all the segments into the wall of the tube 104. The foam member 114 (which can also be referred to as a foam loading member) is generally formed to have a base material (e.g., metallic or polymeric matrix) having gas bubbles (e.g., hollow spherical particles) embedded or formed (e.g., suspended) therein.

[0063] In an example, the foam member 114 may be made of a syntactic foam. In examples, syntactic foams are composite materials synthesized by filling a polymer (e.g., an epoxy resin), cementitious, or ceramic matrix with hollow spheres called micro-balloons or cenospheres as aggregates. The term “syntactic” is used herein to indicate two matters (e.g., the base material and the spheres) “put together.” In other examples, the foam member 114 may be made of a metallic foam where the base material is a metal.

[0064] Figure 6 illustrates an image 600 captured via scanning electron microscopy of a syntactic foam, according to an example implementation. As shown, the foam may have a base material 602 (e.g., a composite, polymeric, or metallic) and particles 604 configured as hollow thin-walled spheres or balloons (e.g., gas-filled and operate as gas bubbles). The presence of hollow particles causes the foam member 114 to have a lower density and higher specific strength (strength divided by density) compared to a solid material without bubbles.

[0065] As an example for illustration, the base material 602 may be a novolac epoxy resin matrix (e.g., ‘832 High Temperature Epoxy’ used in electronics potting applications), a phenolic resin, or any other similar resin or polymer. Such base material may be characterized by having high compressive and tensile strength, adhesive capability to various substratematerials (metals, composites, glass, ceramics, and plastics), resistance to water and humidity, and broad service temperatures (e.g., between -40 and 225 °C).

[0066] A powder made of hollow particles may then be introduced into the base material 602. As an example for illustration, such particles may be 3M™ Glass Bubbles that are introduced into the novolac epoxy to be suspended / embedded therein. Such glass bubbles are hollow spheres with thin walls and are made of soda-lime-borosilicates glass, provided in the form of a powder. The median size particles can be between 18 and 65 microns in diameter, and they may have a crush strength (90% survival) between 250 and 27000 psi. Another illustrative example of such particles is cenospheres (ceramic hollow spheres produced by combustion of coal) such as those produced by CenoStar Corporation with various compositions, densities, and crush strengths.

[0067] These materials and compositions are examples for illustration and are not meant to be limiting. The foam member 114 is generally configured to have a base material with gas bubbles (e.g., hollow particles) suspended / embedded therein. Such foam material has advantageous characteristics that allow the foam member 114 to be crushed locally at the minor diameter of the casing and continue pushing the segments of the anchoring ring 112 that are disposed proximate to larger inner diameter portions of the tube 104.

[0068] Figure 7 is a graph 700 showing multi-modal force-position characteristics of the foam member 114, according to an example implementation. Particularly, line 702 is a plot of the force applied to the foam member 114 versus deformation (compression or position) of the foam member 114. The x-axis shows deformation or position of the foam member 114 in inches (in), and the y-axis shows the force applied to the foam member 114 in pound-force dbf).

[0069] The graph 700 illustrates that the foam member 114 has multi-modal force-position or stress-strain characteristics. Particularly, as force is applied to the foam member 114, initially (e.g., beginning of the cone 108 being pushed into the anchoring ring 112) the foam member 114 exhibits or has an initial elastic region where the foam member 114 is compressed (e.g., between 0 and 0.05 in) elastically until the forces reaches a peak or threshold force (e.g., a crush force) between 13,000 and 15,000 Ibf During the initial elastic region, the foam member 114 may operates as a normal solid as the gas bubbles (hollow particles) are able to move around within the base material without being crushed.

[0070] Thereafter, the foam member 114 exhibits or has a plateau region where the foam member 114 continues to be compressed (e.g., between 0.05 and about 0.27 in) while the applied force remains substantially constant or the same (e.g., between 13,000 and 15,000 Ibf). The terms "substantially constant force,’7"substantially the same force,” or "the force plateaus” are used herein to indicate its general behavior. For example, these terms indicate that the force remains within 20% of a the peak / threshold force. In the example shown in Figure 7. the force remains without about 2.000-3,000 Ibf range from the peak / threshold force.

[0071] In other words, without substantially increasing the force on the cone 108, it continues to move further into the anchoring ring 112, while the foam member 114 may continue undergoing deformation. This occurs due to the crush strength threshold being reached, causing the bubbles to burst with minimal load increase, allowing the foam member 114 to “collapse”.

[0072] As a result, the foam member 114 pushes the segments 500, 502 in contact with the tube 104. then continues pushing the other segments outward (e.g., the segments 504. 506 in Figure 5B that are close to the larger inner diameter portions of the tube 104 continue moving towards the tube 104). The collapsing surface of the foam member 114 maintains some degree of elastic recovery characteristics.

[0073] Thereafter, the foam member 114 exhibits or has a final elastic region where additional load or load increase from 15,000 Ibf to about 27,000 is required to continue compressing or deforming the foam member 114 further from 0.27 in to about 0.425 in. This allows the foam member 114 to drive the segments of the anchoring ring 112 deeper into the wall of the tube 104 so they are well-anchored thereto.

[0074] If the load is then removed, e.g., by pulling the cone 108 back in the proximal direction, the foam member 114 exhibits an elastic recovery region as shown in Figure 7 allowing it to relax partially back to about 0.37 at the end of the load curve. This elastic characteristic allows load to be maintained on all the segments of the anchoring ring 112 after separating from the tool 106.

[0075] As such, the foam member 114, made of a syntactic or metallic foam for example, is characteristically stiff initially, then quite compliant for a range of compression, and lastly, increasingly stiff with further compression. Such multi-modal behavior allows the plug assembly 102 to accommodate imperfections in the roundness of the interior surface of the tube 104, and may allow all the segments of the anchoring ring 112 to be well-anchored to the wall of the tube 104.

[0076] In this manner, the likelihood of the anchoring feature(s) 304 of the segments (e.g., the segment 300) of the anchoring ring 112 disengaging from the interior surface of the tube 104 is reduced or eliminated. Thus, the likelihood of a loss of anchoring resulting in plug failure is also reduced or eliminated.

[0077] Figure 8 is an image taken after a test involving deploying the plug assembly 102 in the tube 104 having an inconsistent inner diameter, according to an example implementation. Particularly, the image shows the foam member 114 mounted to the cone 108 after deploy ment of the plug assembly 102.

[0078] As shown, the foam member 114 has portions such as portion 800 and portion 802 that are disposed in gaps between the segments of the anchoring ring 112, and therefore such portions are not compressed during deployment (during applying a force to insert the cone 108 into the anchoring ring 112). Rather, these portions are allowed to be squeezed into the gaps between the segments of the anchoring ring 112.

[0079] Due to inconsistencies in the inner diameter of the tube 104, the portions of the foam member 114 that interact with or are compressed against the segments of the anchoring ring 112 have various degrees of compression. For example, portion 804 and portion 806 exhibit minimum compression compared to other portions, indicating that the portions 804, 806 have interfaced with segments of the anchoring ring 112 that are at major or larger inner dimeter portions of the tube 104.

[0080] In contrast, portion 808, for example, exhibits maximum compression compared to other portions, indicating that the portion 808 has interfaced with a segment of the anchoring ring 112 that is at the minor or smaller inner dimeter portion of the tube 104. As such, the portions 804, 806 are not compressed as much as the portion 808, which kept getting compressed as the cone 108 is further driven into the anchoring ring 112, because the portions 804, 806 have travelled further without resistance until the corresponding segments of the anchoring ring 112 reached the wall of the tube 104.

[0081] Notably, the multi-modal characteristics (e.g., the threshold force associated with the crush strength, the extent of the plateau region, etc.) of the foam member 114 are adjustable through choice of raw materials (e.g., the base material 602 and the particles 604) and the volume fraction of the particles 604 in the base material 602.

[0082] Figure 9 is a graph 900 showing varying multi-modal characteristics of the foam member based on material choice and volume fraction of particles in the base material,according to an example implementation. Particularly, the graph 900 shows multiple lines similar to the line 702 of the graph 700, but for different types of particles and different volume fraction of the particles 604 in the base material 602.

[0083] Particularly, the lines plot the multi-modal characteristics of the foam member using: S38XHS 3M™ Glass Bubbles with volume fraction of 40%, S38XHS 3M™ Glass Bubbles with volume fraction 60%, S32HS 3M™ Glass Bubbles with volume fraction 40%, S32HS 3M™ Glass Bubbles with volume fraction 60%, S42XHS 3M™ Glass Bubbles with volume fraction 40%, S42XHS 3M™ Glass Bubbles with volume fraction 60%, iM16K 3M™ Glass Bubbles with volume fraction 40%, and iM16K 3M™ Glass Bubbles with volume fraction 60%, respectively.

[0084] The S38XHS 3M™ Glass Bubbles have a density of 0.38 gram / cubic centimeter (g / cm3) and a crush strength (fractional survival rate of 90%) of 5,500 psi. The S32HS 3M™ Glass Bubbles have a density7of 0.32 g / cm3and a crush strength of 6,000 psi. The S42XHS 3M™ Glass Bubbles have a density7of 0.42 g / cm3and a crush strength of 8,000 psi. The iM16K 3M™ Glass Bubbles have a density7of 0.46 g / cm3and a crush strength of 16,000 psi.

[0085] As demonstrated by the lines in the graph 900, the lower the volume fraction of the particles (e.g., 40% versus 60%), the higher the peak or threshold force at the end of the initial elastic region (the line is shifted upward more). Also, the higher the crush strength of the particles, the higher the peak or threshold force at the end of the initial elastic region (the line is shifted upward more).

[0086] As such, the multi-modal characteristics of the foam member 114 can be tuned as desired by vary ing the type and volume fraction of the particles. The choice of base material may also facilitate tuning the multi-modal characteristics of the foam member 114.

[0087] In the figures described above, the foam member 114 is shown generally as a conical component that is hollow and that slopes at a consistent angle. Other features can be implemented in the foam member 114 for further tuning.

[0088] For example, the foam member 114 may be configured to slope at different angles rather than a single, consistent angle throughout. It may also be configured to have a tapering angle that is different from the taper angle of the segments (e.g., of the tapered interior surface 302) of the anchoring ring 112. This way, the foam member 114 may make initial partial contact with the segments, and then gradually increase the contact area as the cone 108 is pushed further in the distal direction. Also, less area of the foam member 114 may be crushed initially such that when a broader / larger contact area is achieved, a particular desired load is reached.

[0089] In examples, other geometric features may be included in the foam member 114. For instance, the foam member 114 may have one or more groove, making it more compressible or malleable. As mentioned above, further tuning can be achieved by changing the volume fraction of the bubbles. For instance, the volume fraction can be changed in a range between 20% and 80%. In some examples, the volume fraction may be betw een 40% and 60%.

[0090] The presence of the foam member 114 may enhance effectiveness of the plug assembly 102 in various way. As mentioned above, the foam member 114 may be configured to have varying slopes to progressively have a larger contact area with the segments of the anchoring ring 112 as the cone 108 and the foam member 114 are driven further into the anchoring ring 112. This way, initially, the foam member 114 may act on one particular end of the segments of the anchoring ring 112, causing a greater pressure / force to act on the segments, driving them harder into the wall of the tube 104. As a result, a deeper 'bite' is achieved, and anchoring is enhanced during the setting process.

[0091] When the tube 104 has an inconsistent inner diameter (e.g., when the interior surface of the tube 104 is not perfectly circular), the presence of the foam member 114 accommodates such inconsistencies, and may ensure that the all the segments of the anchoring ring 112 expand and anchor into the wall of the tube 104.

[0092] Further, the foam member 114 may keep the plug assembly 102 (in the expanded state), intact through the partial elastic recovery portion shown in Figure 7. When the load applied by the tool 106 on the cone 108 is removed, the foam member 114 maintains pushing the segments of the anchoring ring 112 into the tube 104, enhancing anchoring of the plug assembly 102.

[0093] Figure 10 is a flowchart of a method 1000 for deploying the plug assembly 102 in the tube 104, according to an example implementation. The method 1000 may include one or more operations, functions, or actions as illustrated by one or more of blocks 1002-1004. Although the blocks are illustrated in a sequential order, these blocks may also be performed in parallel, and / or in a different order than those described herein. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and / or removed based upon the desired implementation. It should be understood that for this and other processes and methods disclosed herein, flowcharts show functionality and operation of one possible implementation of present examples. Alternative implementations are included within the scope of the examples of the present disclosure in which functions may be executed out of order from that shown or discussed, including substantially concurrent or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art.

[0094] At block 1002, the method 1000 includes positioning the anchoring ring 112 within the tube 104, wherein the anchoring ring 112 comprises a plurality of segments disposed in a circular array.

[0095] At block 1004, the method 1000 includes driving the cone 108 in a distal direction within the anchoring ring 112, wherein the foam member 114 is radially interposed between the cone 108 and the anchoring ring 112, wherein the foam member 114 comprises the base material 602 and gas bubbles formed (e.g., by the particles 604) therein, wherein driving the cone 108 in the distal direction causes the foam member 114 to be compressed between the cone 108 and the anchoring ring 112 as the anchoring ring 112 expands.

[0096] The method 1000 can further include any of the other steps or operations described throughout herein.

[0097] The detailed description above describes various features and operations of the disclosed systems with reference to the accompanying figures. The illustrative implementations described herein are not meant to be limiting. Certain aspects of the disclosed systems can be arranged and combined in a wide variety of different configurations, all of which are contemplated herein.

[0098] Further, unless context suggests otherwise, the features illustrated in each of the figures may be used in combination with one another. Thus, the figures should be generally viewed as component aspects of one or more overall implementations, with the understanding that not all illustrated features are necessary for each implementation.

[0099] Additionally, any enumeration of elements, blocks, or steps in this specification or the claims is for purposes of clarity. Thus, such enumeration should not be interpreted to require or imply that these elements, blocks, or steps adhere to a particular arrangement or are carried out in a particular order.

[0100] Further, devices or systems may be used or configured to perform functions presented in the figures. In some instances, components of the devices and / or systems may be configured to perform the functions such that the components are actually configured and structured (withhardware and / or software) to enable such performance. In other examples, components of the devices and / or systems may be arranged to be adapted to, capable of, or suited for performing the functions, such as when operated in a specific manner.

[0101] By the term ‘'substantially’’ or ‘'about” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those with skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

[0102] The arrangements described herein are for purposes of example only. As such, those skilled in the art will appreciate that other arrangements and other elements (e.g., machines, interfaces, operations, orders, and groupings of operations, etc.) can be used instead, and some elements may be omitted altogether according to the desired results. Further, many of the elements that are described are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, in any suitable combination and location.

[0103] While various aspects and implementations have been disclosed herein, other aspects and implementations will be apparent to those skilled in the art. The various aspects and implementations disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope being indicated by the following claims, along with the full scope of equivalents to which such claims are entitled. Also, the terminology used herein is for the purpose of describing particular implementations only, and is not intended to be limiting.

[0104] Embodiments of the present disclosure can thus relate to one of the enumerated example embodiments (EEEs) listed below.

[0105] EEE 1 is a plug assembly comprising: a cone; an anchoring ring mounted to the cone and comprising a plurality of segments disposed in a circular array; and a foam member that is radially interposed between the cone and the anchoring ring, wherein the foam member comprises a base material and gas bubbles formed therein, wherein during deployment of the plug assembly, the cone is driven in a distal direction, thereby expanding the anchoring ring as the foam member is compressed betw een the cone and the anchoring ring.

[0106] EEE 2 is the plug assembly of EEE 1, wherein the foam member is made as a syntactic foam or a metallic foam.

[0107] EEE 3 is the plug assembly of any of EEEs 1 -2, wherein the base material is formed from a polymeric material or a metallic material.

[0108] EEE 4 is the plug assembly of any of EEEs 1-3, wherein the base material comprises an epoxy resin matrix.

[0109] EEE 5 is the plug assembly of any of EEEs 1-4, wherein the gas bubbles are formed by hollow particles disposed in the base material.

[0110] EEE 6 is the plug assembly of EEE 5, wherein the hollow' particles comprise glass spheres that are hollow' and thin- alled.

[0111] EEE 7 is the plug assembly of any of EEEs 1-6, wherein the foam member is configured to have multi-modal force-position characteristics, enabling the foam member to have an initial elastic region as the foam member is compressed between the cone and the anchoring ring, followed by a plateau region where the foam member continues to be compressed while a force applied to the foam member plateaus.

[0112] EEE 8 is a system comprising: a tube; a tool; and the plug assembly of any of EEEs 1- 7. For example, the plug assembly comprises: a cone configured to be coupled to tool, an anchoring ring mounted to the cone and comprising a plurality' of segments disposed in acircular array, and a foam member that is radially interposed between the cone and the anchoring ring, wherein the foam member comprises a base material and gas bubbles formed therein, wherein during deployment of the plug assembly, the tool drives the cone toward the anchoring ring, thereby expanding the anchoring ring as the foam member is compressed between the cone and the anchoring ring.

[0113] EEE 9 is the system of EEE 8, wherein the foam member is made as a syntactic foam or a metallic foam.

[0114] EEE 10 is the system of any of EEEs 8-9, wherein the base material is formed from a polymeric material or a metallic material.

[0115] EEE 11 is the system of any of EEEs 8-10, wherein the base material comprises an epoxy resin matrix.

[0116] EEE 12 is the system of any of EEEs 8-11, wherein the gas bubbles are formed by hollow particles disposed in the base material.

[0117] EEE 13 is the system of EEE 12, wherein the hollow particles comprise glass spheres that are hollow and thin-walled.

[0118] EEE 14 the system of any of EEEs 8-13, wherein the foam member is configured to have multi-modal force-position characteristics, enabling the foam member to have an initial elastic region as the foam member is compressed between the cone and the anchoring ring, followed by a plateau region where the foam member continues to be compressed while a force applied to the foam member plateaus.

[0119] EEE 15 is the system of EEE 14, wherein the tube has an interior surface that is out-of-roundness, and wherein the foam member enables pressing segments of the plurality7of segments that are disposed proximate a larger inner diameter portion of the tube into the tube for anchoring during the plateau region.

[0120] EEE 16 is the system of any of EEEs 8-15, wherein respective segments of the anchoring ring comprises one or more anchoring features disposed on an exterior surface of the anchoring ring to facilitate affixing the anchoring ring to the tube in which the plug assembly is deployed via the tool.

[0121] EEE 17 is a method of deploying the plug assembly of any of EEEs 1-7 using the system of any of EEEs 8-16. For example, the method comprises: positioning an anchoring ring within a tube, wherein the anchoring ring comprises a plurality of segments disposed in a circular array; and driving a cone in a distal direction within the anchoring ring, wherein a foam member is radially interposed between the cone and the anchoring ring, wherein the foam member comprises a base material and gas bubbles formed therein, wherein driving the cone in the distal direction causes the foam member to be compressed between the cone and the anchoring ring as the anchoring ring expands.

[0122] EEE 18 is the method of EEE 17, wherein the foam member is configured to have multi-modal force-position characteristics such that driving the cone in the distal direction comprises: compressing the foam member elastically until a threshold force is reached; and thereafter, applying substantially the same force on the foam member, while the foam member continues to be compressed between the cone and the plurality of segments of the anchoring ring.

[0123] EEE 19 is the method of EEE 18, wherein the tube has an interior surface that is out-of-roundness such that a first subset of segments disposed proximate a smaller inner diameter portion of the tube reach the tube during expansion before a second subset of segments disposed proximate a larger inner diameter portion of the tube, and wherein applying substantially the same force on the foam member after the threshold force is reached comprises: continuing to expand the second subset of segments into the tube for anchoring.

[0124] EEE 20 is the method of any of EEEs 17-19, wherein respective segments of the anchoring ring comprise one or more anchoring features disposed on an exterior surface of the anchoring ring, and wherein driving the cone to expand the anchoring ring comprises: driving the one or more anchoring features into the tube to affix the anchoring ring to the tube.

Claims

CLAIMSWhat is claimed is:

1. A plug assembly comprising:a cone;an anchoring ring mounted to the cone and comprising a plurality of segments disposed in a circular array; anda foam member that is radially interposed between the cone and the anchoring ring, wherein the foam member comprises a base material and gas bubbles formed therein, wherein during deployment of the plug assembly, the cone is driven in a distal direction, thereby expanding the anchoring ring as the foam member is compressed between the cone and the anchoring ring.

2. The plug assembly of claim 1, wherein the foam member is made as a syntactic foam or a metallic foam.

3. The plug assembly of claim 1, wherein the base material is formed from a polymeric material or a metallic material.

4. The plug assembly of claim 1. wherein the base material comprises an epoxy resin matrix.

5. The plug assembly of claim 1, wherein the gas bubbles are formed by hollow particles disposed in the base material.

6. The plug assembly of claim 5, wherein the hollow particles comprise glass spheres that are hollow and thin-walled.

7. The plug assembly of claim 1, wherein the foam member is configured to have multi-modal force-position characteristics, enabling the foam member to have an initial elastic region as the foam member is compressed between the cone and the anchoring ring, followed by a plateau region where the foam member continues to be compressed while a force applied to the foam member plateaus.

8. A system comprising:a tube;a tool; anda plug assembly comprising:a cone configured to be coupled to tool,an anchoring ring mounted to the cone and comprising a plurality of segments disposed in a circular array, anda foam member that is radially interposed between the cone and the anchoring ring, wherein the foam member comprises a base material and gas bubbles formed therein, wherein during deployment of the plug assembly, the tool drives the cone toward the anchoring ring, thereby expanding the anchoring ring as the foam member is compressed between the cone and the anchoring ring.

9. The system of claim 8. wherein the foam member is made as a syntactic foam or a metallic foam.

10. The system of claim 8, wherein the base material is formed from a polymeric material or a metallic material.

11. The system of claim 8, wherein the base material comprises an epoxy resin matrix.

12. The system of claim 8, wherein the gas bubbles are formed by hollow particles disposed in the base material.

13. The system of claim 12, wherein the hollow particles comprise glass spheres that are hollow and thin-walled.

14. The system of claim 8, wherein the foam member is configured to have multimodal force-position characteristics, enabling the foam member to have an initial elastic region as the foam member is compressed between the cone and the anchoring ring, followed by a plateau region where the foam member continues to be compressed while a force applied to the foam member plateaus.

15. The system of claim 14, wherein the tube has an interior surface that is out-of-roundness, and wherein the foam member enables pressing segments of the plurality of segments that are disposed proximate a larger inner diameter portion of the tube into the tube for anchoring during the plateau region.

16. The system of claim 8, wherein respective segments of the anchoring ring comprises one or more anchoring features disposed on an exterior surface of the anchoring ringto facilitate affixing the anchoring ring to the tube in which the plug assembly is deployed via the tool.

17. A method comprising:positioning an anchoring ring within a tube, wherein the anchoring ring comprises a plurality of segments disposed in a circular array; anddriving a cone in a distal direction within the anchoring ring, wherein a foam member is radially interposed between the cone and the anchoring ring, wherein the foam member comprises a base material and gas bubbles formed therein, wherein driving the cone in the distal direction causes the foam member to be compressed between the cone and the anchoring ring as the anchoring ring expands.

18. The method of claim 17, wherein the foam member is configured to have multimodal force-position characteristics such that driving the cone in the distal direction comprises:compressing the foam member elastically until a threshold force is reached; and thereafter, applying substantially the same force on the foam member, while the foam member continues to be compressed between the cone and the plurality of segments of the anchoring ring.

19. The method of claim 18, wherein the tube has an interior surface that is out-of-roundness such that a first subset of segments disposed proximate a smaller inner diameter portion of the tube reach the tube during expansion before a second subset of segments disposed proximate a larger inner diameter portion of the tube, and wherein applying substantially the same force on the foam member after the threshold force is reached comprises:continuing to expand the second subset of segments into the tube for anchoring.

20. The method of claim 17, wherein respective segments of the anchoring ring comprise one or more anchoring features disposed on an exterior surface of the anchoring ring, and wherein driving the cone to expand the anchoring ring comprises:driving the one or more anchoring features into the tube to affix the anchoring ring to the tube.

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