Title:
Downhole Tool Having Slip Composed of Composite Ring
Kind Code:
A1


Abstract:
A single piece composite slip component is disclosed, making it easier and more feasible for milling up a composite plug after use. Moreover, because the composite slip component is one piece during deployment, and not in segments like conventional slip segments, it can better withstand the high speeds and higher fluid velocities and pressures downhole.



Inventors:
Stage, Matthew R. (Houston, TX, US)
Young, Jonathan A. (Houston, TX, US)
Pritchett, Wesley C. (Liberty, TX, US)
Rochen, James A. (Waller, TX, US)
Application Number:
14/484378
Publication Date:
03/12/2015
Filing Date:
09/12/2014
Assignee:
WEATHERFORD/LAMB, INC.
Primary Class:
Other Classes:
166/217
International Classes:
E21B23/01; E21B33/129; E21B23/06; E21B33/124
View Patent Images:
Related US Applications:
20010022224Cementing spacers for improved well cementationSeptember, 2001Haberman
20070114069Apparatus for positioning and stabbing pipe in a drilling rig derrickMay, 2007Hooper et al.
20170114272Scale Inhibitor and Methods of Using Scale InhibitorsApril, 2017Vo et al.
20150041126BYPASS STEAM INJECTION AND PRODUCTION COMPLETION SYSTEMFebruary, 2015Boyle et al.
20060016591Apparatus and method for agitating reservoir while pumpingJanuary, 2006Cote
20160186524SUBSEA IN SITU LASER FOR LASER ASSISTED BLOW OUT PREVENTER AND METHODS OF USEJune, 2016Faircloth et al.
20120031624FLOW TUBE FOR USE IN SUBSURFACE VALVESFebruary, 2012Goughnour et al.
20150369023WELL INJECTION AND PRODUCTION METHOD AND SYSTEMDecember, 2015Macphail et al.
20140166291SURFACTANT SYSTEM AS A SELF-DIVERTED ACID FOR WELL STIMULATIONJune, 2014Friesen et al.
20140096949DRILL HOLE PLUG SYSTEMApril, 2014Mclaren
20140110109DIRECT STEAM GENERATION OF BOILER BLOWDOWNApril, 2014Latimer et al.



Primary Examiner:
BUTCHER, CAROLINE N
Attorney, Agent or Firm:
Weatherford/Precision (Houston, TX, US)
Claims:
What is claimed is:

1. A downhole apparatus, comprising: a mandrel; a cone disposed on the mandrel; a first slip having a cylindrical body with first and second surfaces and first and second ends, the cylindrical body disposed with the first surface about the mandrel and with the first end adjacent the cone, the cylindrical body defining only a single slit extending partially from the first end toward the second end, the cylindrical body radially expandable outward from the mandrel through interaction of the first end with the cone; and one or more inserts disposed on the cylindrical body and exposed at the second surface.

2. The apparatus of claim 1, wherein the first surface defines an incline at the first end.

3. The apparatus of claim 1, wherein the single slit extends a greater distance along the second surface than along the first surface of the cylindrical body.

4. The apparatus of claim 1, wherein the cylindrical body at the second end comprises an interconnection at the single slit, the interconnection hinging one side of the single slit with an opposite of the single slit.

5. The apparatus of claim 1, wherein the interconnection defines a triangular cross-section.

6. The apparatus of claim 1, wherein the apparatus comprises a plug, a packer, a liner hanger, an anchoring device, or a downhole tool.

7. The apparatus of claim 1, comprising a packing element disposed on the mandrel, wherein the cone and the first slip are disposed on an uphole end of the mandrel adjacent the packing element.

8. The apparatus of claim 7, comprising a second slip disposed on a downhole end of the mandrel adjacent an opposite side of the packing element.

9. The apparatus of claim 8, wherein the second slip comprises a plurality of independent segments disposed about the mandrel.

10. A downhole apparatus, comprising: a mandrel; a cone disposed on the mandrel; a cylindrical body having first and second surfaces and having first and second ends, the cylindrical body disposed with the first surface about the mandrel and with the first end adjacent the cone, the cylindrical body defining only two slits extending partially from the first end toward the second end, the cylindrical body radially expandable outward from the mandrel through interaction of the first end with the cone; and one or more inserts disposed on the cylindrical body and exposed at the second surface.

11. The apparatus of claim 10, wherein the first surface defines an incline at the first end.

12. The apparatus of claim 10, wherein each of the two slit extends a greater distance along the second surface than along the first surface of the cylindrical body.

13. The apparatus of claim 10, wherein the cylindrical body at the second end comprises interconnections at each of the two slits, the interconnections hinging one side of the each slit with an opposite of the each slit.

14. The apparatus of claim 10, wherein each of the interconnections defines a triangular cross-section.

15. The apparatus of claim 10, wherein the apparatus comprises a plug, a packer, a liner hanger, an anchoring device, or a downhole tool.

16. The apparatus of claim 10, comprising a packing element disposed on the mandrel, wherein the cone and the first slip are disposed on an uphole end of the mandrel adjacent the packing element.

17. The apparatus of claim 10, comprising a second slip disposed on a downhole end of the mandrel adjacent an opposite side of the packing element.

18. The apparatus of claim 17, wherein the second slip comprises a plurality of independent segments disposed about the mandrel.

19. The apparatus of claim 10, wherein the only two slits are disposed on radially opposite sides of the cylindrical body.

20. A method of setting a downhole tool against an adjacent surface, the method comprising: interacting a first end of a cylindrical body with a surface of the tool; expanding the cylindrical body radially outward from the tool with the interaction as at least one and not more than two arcuate members by separating the cylindrical body along at least one and not more than two slits extending partially from the first end toward a second end of the cylindrical body; engaging one or more inserts on the cylindrical body against the adjacent surface; transmitting load from the surface to the cylindrical body; and transmitting the load from the cylindrical body to the one or more inserts.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Prov. Appl. 61/877,113, filed 12 Sep. 2013, which is incorporated herein by reference.

BACKGROUND OF THE DISCLOSURE

An oil or gas well includes a bore extending into a well to some depth below the surface. Typically, the bore is lined with tubulars or casing to strengthen the walls of the bore. To further strengthen the walls of the bore, the annular area formed between the casing and the bore is typically filled with cement to permanently set the casing in the bore. The casing is then perforated to allow production fluid to enter the bore and to be retrieved at the surface of the well.

Typically, downhole tools with sealing elements are placed within the bore to isolate the production fluid or to manage production fluid flow through the well. For example, a plug or packer is placed within a bore to isolate upper and lower sections of production zones. Thus, by creating a pressure seal in the bore, these plugs allow pressurized fluids or solids to treat an isolated formation. These tools are usually constructed of cast iron, aluminum, or other alloyed metals, but have a malleable, synthetic element system. The plug or packer system can also be composed of non-metallic components made of composites, plastics, and elastomers.

Slips are a part of these downhole tools, such as plugs and packers, and the slips can also be composed of metallic or non-metallic components. However, metallic slips can cause problems during mill-up operations of the downhole tools in horizontal wells. As one solution to these problems, slip segments composed of composite material can be held on a mandrel of a downhole tool, such as a plug. These composite slip segments are typically held together with bands on the tool's mandrel until actuated to engage the surrounding casing downhole. Additionally, the composite slips segments can have inserts or buttons that are composed of metallic materials (e.g., tungsten carbide or the like) that grip the inner wall of the surrounding casing or tubular. Examples of downhole tools with slip segments with inserts are disclosed in U.S. Pat. Nos. 6,976,534 and 8,047,279.

FIG. 1A illustrates a fracturing system 10 having a composite plug according to the prior art disposed in a bore. As shown, the system 10 can having at least one of the composite plugs 100 disposed within the casing 12 lining the bore. Casing 12, as known in the art, is used to further strengthen the walls of the bore, and therefore the area formed between the casing 12 and the bore is typically filled with cement to permanently set the casing 12 within the bore. Also as shown, the casing 12 is perforated 15 to allow production fluid to enter the casing 12 so the produced fluids can be retrieved at the surface of the well. The casing 12 is perforated 15 in formation zones 14 as shown. The formation zones 14 indicate zones where production fluid potentially exists. Accordingly, the casing 12 at these zones 14 is perforated 15 in order to allow fluid to flow into the casing 12 and eventually to the surface.

FIG. 1B illustrates a composite plug 100 of the prior art in more details. As shown, the plug 100 has a mandrel 102. As known in the art, the mandrel 102 is designed with a cylindrical hole (i.e., bore) through the center to allow for pressure equalization and well flow back prior to milling up the plug 100 after its use downhole. Also as shown, the plug 100 has uphole and downhole slip assemblies 104a-b, each having slip segments 110, inserts 114, and bands 112. The plug 100 also has uphole and downhole cones 106a-b, a setting or push ring 105, and a packing element 109, which will be discussed in detail below.

Conventional composite slips 104a-b include multiple slip segments 110 disposed around the mandrel 102. Bands 112 typically hold the slip segments 110 in place, and the composite segments 110 include one or more metallic inserts 114 in order to engage the casing (12).

During operation, the slip segments 110 move away from the mandrel 102 and compress the inserts 114 against the surrounding casing (12) when the plug 100 is compressed. Examples of the operation of conventional slip components of such a plug 100 are disclosed in U.S. Pat. No. 7,124,831 which is incorporated within in its entirety.

As mentioned, the conventional slip assemblies 104a-b may be composed of cast iron, aluminum, or other alloyed metals. However, in one problem associated with such metallic slip assemblies, it is often times less desirable to use such metallic components due to the mill-ability of the components. For example, plugs 100 are sometimes intended to be temporary and must be removed to access the casing (12). Rather than de-actuating the plug 100 and bringing it to the surface of the well, the plug 100 is typically destroyed with a rotating milling or drilling device.

As the mill contacts the plug 100, the plug 100 is “drilled up” or reduced to small pieces that are either washed out of the bore or simply left at the bottom of the bore. The more metal parts making up the plug 100, the longer the milling operation takes. Furthermore, metallic components like aluminum also typically require numerous trips in and out of the bore to replace worn out mills or drill bits. Also, aluminum mandrels are typically composed of very expensive aerospace grade materials, and are thus not economically feasible for such use.

In another problem, the conventional slip assemblies even if composed of composite materials are oftentimes difficult to manufacture. For example, the conventional slip assemblies 104a-b are often manufactured as multiple, independent segments 110. Then, the slip segments 10 are positioned around the mandrel 102 of the plug 100 and are held together with restraining bands 112 to keep the segments 110 against the mandrel 102 for deploying in the casing 110 until actuated. Although this form of manufacture may work, it is often time-consuming and involves a very complicated manufacturing and assembly process.

Further, other problems associated with using slip segments 110 held by restraining bands 112 arise when the tool 100 is deployed downhole. As is known in the art, downhole conditions vary, and high pressures and high fluid velocities may disengage or render unusable conventional slip assemblies 104a-b. For example, during the deployment of the plug 100, the fluid in the bore may have a high enough pressure and/or may have an increased velocity as it transitions past the slip assembly 104a-b that the slip assembly 104a-b can be damaged and disengage from the mandrel 102, despite being held together by bands 112. That is, the bands 112 may not be strong enough to hold the segments 110 together in certain downhole conditions.

Accordingly, there is a need for a non-metallic slip component that will effectively handle the high temperatures and the high pressures downhole. There is also a need for a slip component that is easier and faster to manufacture, while remaining economically feasible. Finally, there is a need for a non-metallic slip assembly that can withstand the high speeds and fluid velocities during run in on a downhole tool through casing.

The subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.

SUMMARY OF THE DISCLOSURE

Conventional slip components of downhole tools are typically composed of cast iron, aluminum, or other alloyed metals. However, the more metal parts making up the plug (i.e., slip components) the longer the milling operation takes. Also, metallic components like aluminum also typically require numerous trips in and out of the bore to replace worn out mills or drill bits and are typically composed of very expensive aerospace grade materials, and are thus not economically feasible for such use. Therefore, a single piece composite slip component is disclosed, making it easier and more feasible for milling up a plug after use. Moreover, because the composite slip component is one piece during deployment, and not in segments like conventional slip segments, it can better withstand the high speeds and higher fluid velocities and pressures downhole. This is important aspect when pumping down extended reach horizontals.

A downhole apparatus have a mandrel with a cone disposed thereon. In general, the apparatus can be a plug, a packer, a liner hanger, an anchoring device, or a downhole tool.

The single piece composite slip component is disposed on the mandrel and has a cylindrical body with first and second surfaces and first and second ends. The cylindrical body is disposed with the first surface about the mandrel and with the first end adjacent a cone on the mandrel of the downhole tool. In one arrangement, the cylindrical body defines only a single slit extending partially from the first end toward the second end. In another arrangement, the cylindrical body defines only two slits extending partially from the first end toward the second end. These two slits can be disposed on radially opposite sides of the cylindrical body.

The cylindrical body is radially expandable outward from the mandrel through interaction of the first end with the cone, and one or more inserts disposed on the cylindrical body and exposed at the second surface engage in the surrounding tubular wall of casing or the like.

When interacting the first end of the cylindrical body with the cone, the cylindrical body expands radially outward from the tool with the interaction as at least one and not more than two arcuate members by separating the cylindrical body along the one and not more than two slits extending partially from the first end toward a second end of the cylindrical body. The one or more inserts on the cylindrical body engage against the adjacent surface. Load is transmitted from the cone to the cylindrical body, and the load is transmitted from the cylindrical body to the one or more inserts.

To interact with the cone, the first surface can define an incline at the first end. The single or two slits extend a greater distance along the second surface than along the first surface of the cylindrical body. The cylindrical body at the second end can have an interconnection at the slit so that the interconnection can hinge one side of the single slit with an opposite of the single slit. The interconnection can define a triangular cross-section.

A packing element can be disposed on the mandrel, and the cone and the single piece composite slip component can be disposed on an uphole end of the mandrel adjacent the packing element. A second slip can also be disposed on a downhole end of the mandrel adjacent an opposite side of the packing element. This second slip can include a plurality of independent segments disposed about the mandrel.

The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a plug disposed in a bore according to the prior art.

FIG. 1B illustrates a plug of the prior art.

FIG. 2A illustrates an elevational view a plug having a composite slip component according to the present disclosure.

FIG. 2B illustrates an elevational view of another side of the plug offset 90-degrees from FIG. 2A.

FIG. 2C illustrates a detailed view of the disclosed slip component on the plug.

FIGS. 3A-3C illustrates an end view, a cross-sectional view, and a perspective view of the disclosed slip component.

FIG. 3D is a detailed view of a hole for an insert of the disclosed slip.

FIGS. 4A-4B schematically illustrates the disclosed slip component in different engagements with the surrounding casing during operation.

FIG. 5 illustrates an elevational view of another plug having two composite slips according to the present disclosure.

FIGS. 6A-6C illustrates an end view, a cross-sectional view, and a perspective view of another composite slip component according to the present disclosure.

FIG. 6D schematically illustrates the disclosed slip component engaged with the surrounding casing during operation.

DETAILED DESCRIPTION OF THE DISCLOSURE

FIGS. 2A-2B illustrate elevational views a composite plug 100 having a composite slip component 120 according to the present disclosure. The two views in FIGS. 2A-2B show sides of the plug 100 at 90-degree offset from one another. As shown, the plug 100 includes a mandrel 102 and sealing elements 104a-b, 106a-b, 108a-b, and 109. In general, the plug 100 can be a bridge plug intended to contain pressure from above and below when setting in casing, or it can be a fracture plug intended mainly to contain pressure from above during a fracture operation.

Disposed on the mandrel 102, the plug 100 has uphole and downhole slip assemblies 104a-b, cones 106a-b, and backups 108a-b with a packing element 109 disposed between them. The uphole slip assemblies 104a as shown includes the composite slip component 120 according to the present disclosure, while the downhole assembly includes a conventional slip assembly having segments 110 with inserts 114 and held by bands 112.

As best shown in the detailed view of FIG. 2C, the slip component 120 has a cylindrical body or 122 with insert holes 128 for holding inserts 130. As discussed in more detail below, the composite slip component 120 has one or more slits 124 and interconnecting portions or hinging areas 127. Preferably, the cylindrical body 122 has only one or at most two slits 124 so that the cylindrical body 122 forms a practically continuous ring or cylinder with only one or at most two arcuate portions divided by the slit(s) 124.

Regarding the disposition of the slip component 120 and the conventional slip assembly 104b at uphole and downhole ends of the plug 100, the disclosed plug 100 is not limited to this particular configuration. That is, the plug 100 may comprise composite slip components 120 on both uphole and downhole ends, or the plug 100 may comprise a slip component 120 at the downhole end, while having a conventional slip assembly 104b uphole. Accordingly, any other combination of slip component 120 with or without conventional slip assembly 104b can be used on the plug 100.

However, regardless of which is deployed uphole or downhole, it is desired to deploy a slip assembly having greater structural stability (e.g., the disclosed slip component 120) at the uphole end of the plug 100 and to deploy a slip assembly with increased strength at the downhole end of the plug. This is due in part to what the uphole assembly 104a may encounter during run in at high speeds. The uphole assembly 104a may experience more adverse effects from fluid flow or friction during run in of the plug 100 in the casing (12) which could damage a conventional slip assembly with segments. Because the slip component 120 is a continuous cylindrical component, it is less prone to damage during run in.

Choice of what type of assembly to use at the downhole end is also based on the operation of the plug 100. For example, because the downhole slip assembly has to remain in place, braking and engaging the inner bore, while the uphole slip is compressed toward the downhole slip, the downhole slip assembly may experience certain pressures or effects that the uphole slip assembly may not experience. Thus, if the downhole slip assembly cannot withstand certain forces, the downhole slip assembly may disengage from the casing. As a result, the plug 100 may fail during use. For these reasons, the uphole assembly 104a of the present disclosure may use the disclosed slip component 120, while the downhole assembly 104b may use other types of segments 110 and the like.

In operation, the element system 103 of the plug 100 shown in FIGS. 2A-2B is compressed, and expands radially outward from the plug 100 to sealingly engage a surrounding tubular or casing (not shown). To obtain this expansion, forces are exerted on the push ring 105. As the slip component 120 moves down in relation to downhole slip assembly 104b, the packing element 109 is compressed, and the slip component 120 and slip assembly 104b are driven up their adjacent cones 106a-b. The movement of the cones 106a-b and the slip component 120 and assembly 104b axially compress and radially expand the packing element 109, thereby forcing the packing element 109 radially outward from the plug 100 to contact the inner surface of the casing (12). In this manner, the compressed packing element 109 provides a fluid seal to prevent movement of fluids across the plug 100.

Further, as the packing element 109 expands to provide a fluid seal between the plug 100 and the casing (12), the slip component 120 and assembly 104b move along the surface of cones 106a-b. As a result, the slip component 120 and assembly 104b will expand outward with respect to the plug 100, thereby being driven into the casing to hold plug 100 in place.

With particular reference to the offset views of FIGS. 2B-2C, one of the at least one or two slits 124 of the slip component 120 of the plug 100 can be more easily shown. Here, the slit 124 extends from the bottom of the slip component 120 all the way to the top, where an interconnecting portion 127 holds the component 120 together around the mandrel 102. Further, as can be seen in FIGS. 2A-2C, the slip component 120 has a cylindrical body 122 that surrounds the plug 100.

Also, the slip component 120 comprises insert holes 128 that contain inserts 130 disposed within them. In this embodiment, the inserts 130 may be disposed around the cylindrical body 122 of the slip component 120 in a variety of different ways. For example, the inserts 130 can be disposed around the cylindrical body 122 in a way that the inserts 130 are separated by an equal space. Furthermore, the inserts 130 may be aligned in rows, aligned diagonally along cylindrical body 122, or any other configuration. The purpose of the configuration of the inserts 130 around the cylindrical body 122 is to allow as many inserts 130 as possible to be disposed therein, while maintaining the structural soundness of the composite material.

The slip component 122 is manufactured in a manner similar to the continuous fiber winding process described in U.S. Pat. No. 7,124,831, which is used for manufacturing plugs and is incorporated herein by reference. In general, the manufacturing process involves wet winding a continuous fiber around a temporary mandrel to form the cylindrical body 122 of the slip component. The fiber is preferably wound in an overlapping lattice structure. The resin impregnated fiber is then heated, cured, and cooled so the cylindrical body 122 can be removed from the temporary mandrel and machined. The outer and inner diameters of the cylindrical body 122 may be machined to a certain size, tolerance, or smoothness. Also, any of the various slits 124, holes 128, and the like may be machined in the cylindrical body 122. These and any other additional steps available in the art can be used so that slip component can be installed on the mandrel 102 of the plug 100 with other components for future deployment in the harsh environment downhole.

As show in FIGS. 2A-2C, the holes 128 for the inserts 130 may be arranged in a staggered pattern intended to maintain the overall strength of the component's material. Thus, any fibers in the winding making up the body 122 of the component 122 that have been cut to form one of the holes 128 may be cut elsewhere on the body 122 to form another of the holes 128. In this way, a number of fiber windings will remain intact around the body 122 and maintain the body's overall strength.

As can be seen in FIG. 2C, the insert holes 128 are not necessarily disposed parallel to the surface of the slip component 120 itself, although they can be. As will be described in detail later, the inserts 130 are preferably disposed within or through the cylindrical body 122 of the slip component 120 at an angle. This angle allows the inserts to more thoroughly engage the bore casing (12) in a way that will allow the inserts 130 to provide the most stability for the slip component 120, and consequently the bridge plug 100 itself, after the plug 100 has been engaged and has formed a seal within the casing (12).

With an understanding of the plug 100 and the disclosed slip component, discussion turns to further details of the slip component 120. FIGS. 3A-3C illustrate an end view, a cross-sectional view, and a perspective view of the disclosed slip component 120. With respect to FIG. 3A, the end view of the slip component 120 shows the cylindrical body 122 of the slip component 120. As shown, there are numerous insert holes 128 having the inserts 130 disposed within them. Furthermore, FIG. 3A shows how the slip component 120 has at least two slits 124 disposed on opposite sides of the cylindrical component 120. Consistent within the present disclosure, there can be at least one or two slits 124 disposed around the cylindrical body 122. More slits are not preferred, but may be used if desired.

FIG. 3B shows a cross-sectional view of the slip component 120. As best shown in this view, the slip component 120 contains a ramp 126 on the inside surface 121 at one end of the cylindrical body 122. Also, the body 122 has two slits 124 and interconnecting portions 127. The ramp 126 serves the purpose of easing the transition of the slip component 120 over the cones (i.e., the ramp 126 allows the slip component 122 to be more easily transitioned over the outer surface of cones 106a-b on the plug 100 of FIGS. 2A-2C).

Furthermore, when the slip component 120 is compressed over its adjacent cone (106a), the slip component 120 will separate along the slits 127 and will fracture, break, or tear along the interconnecting portions 127, creating slip element halves (125a-b) that allow the slip component 120 to expand more efficiently over the conical surface (107a) of the cone (106a). Due to the material makeup of the slip component 120 (i.e., continuous fiber winding as described in U.S. Pat. No. 7,124,831), when the slip component 120 is pushed over the cone (106a), the slip component 120 flexes and conforms to the larger radius of the casing (12), while the inserts (130) penetrate the casing (12) and anchor the slip component 120 in place.

Also, since the slip component 120 is one piece during running in the hole, and does not comprise independent segments like a conventional slip assembly of the prior art held together by bands, the slip component 120 can better withstand the high speeds and higher fluid velocities encountered during run in the plug 100. In this regard, allowing the slip component 120 to expand more efficiently over its cone (106a) will allow the slip component halves (125a-b) to more succinctly engage the casing (12). In turn, allowing the slip component 120 to more succinctly engage the casing (12) will allow the inserts (130) to engage the inner surface of the casing (12) and provide an anchor for the plug 100.

FIG. 3C shows a perspective view of the slip component 120. In this view, the slip component 120 has the cylindrical body 122, the one or more slits 124, and one or more insert holes 128. As can be shown in this embodiment, the slits 124 extend from the bottom of the slip component 120 to the top of the slip component 120. However, rather than completely separating the cylindrical body 122, the slits 124 preferably stop at the interconnecting portions 127 of the slip component 120. However, the slip component 120 is not limited to the one or more slits 124 of the slip component 120 having a single interconnecting portion 127. The slip component 120 may further comprise more than one interconnecting portion 127. For example, an interconnecting portion 127 may be disposed at each end of the one or more slits 124, forming slot-like formations within the slip component 120. Therefore, the slip component 120 may comprise an interconnecting portion 127 at the top of a slit 124 and at the bottom of the slit 124, having the opening for the slit 124 disposed between the two interconnecting portions 127.

Further, the slit elements 124 can extend from either end of the slip component 120, and/or extend thru the inner cylindrical surface (121) with an axial cut that does not penetrate to the outer surface of the slip component 120.

Further, in this view, the insert holes 128 are shown disposed throughout the outer surface of the slip component 120. Moreover, although this embodiment only shows two slit elements 124, there may be one slit 124 or more slits disposed around the circumference of the slip component 120.

The slits 124 are formed to control breakage of the slip component 120 during expansion. Therefore, the depth, the length, the width, and any other characteristics of the slits 124 can be varied depending on the strength of the composite material used, the expected forces encountered during expansion, and other factors. As shown here, the slits 124 are formed on opposite sides of the cylindrical body 122 and extend from a distal end to almost a proximal end of the component 120 adjacent the push ring 105. The slits 124 are defined completely through the thickness of the cylindrical body 122, although this may not be strictly necessary. Additionally, more of the slit 124 may be formed on the outside of the body 122 than the inside so that the interconnecting portions 127 have a triangular cross-section as shown in FIG. 3B. The interconnecting portions 127 may have many different shapes, but preferably has a similar triangular cross-sectional area). Overall, the slits 124 in this arrangement may be configured to control breakage at about 3,000 to 5,000 lbs.

FIG. 3D is a detailed view of one of the insert holes 128 of the disclosed slip component 120. As shown, the insert hole 128 is disposed within the outer surface of the slip component 120 at a depth D. As described above, the depth D may extend all the way through the outer surface of the slip component 120, or may only extend partially through the slip component 120.

Also, the insert hole 128 may be disposed within the outer surface of the slip component 120 at an angle θ. The purpose of disposing inserts 130 at an angle θ is so that when the plug 100 is activated and the slip component 120 is expanded outward and fractured into halves (125a-b) contacting the casing (12) of the bore, the inserts 130 within the slip component halves (125a-b) will engage the casing (12) at an angle to ensure maximum stability of the plug 100 as it is sealed within the casing (12).

FIGS. 4A-4B schematically illustrate the disclosed slip component 120 in different engagements with the surrounding casing 12 during operation. Depending on the number of slits 124 and the arrangement of the slits 124 within the slip component 120, there may be many different ways that the slip component 120, or slip component halves (125a-b) may engage the casing 12.

Referring first to FIG. 4A, the slip component 120 is disposed within casing 12. This end view of the casing 12 shows an example of how the slip component 120 engages the casing 12 after the slip component 120 has been compressed over the conical surface of its adjacent cone (e.g., 106a). As shown, when the slip component 120 is compressed over the conical surface of the cone (106a), the outer surface of each slip component halve 125a-b will engage the casing 12, causing inserts 130 to engage the casing 12.

As previously described, this engagement of the inserts 130 within the casing 12 provides stability for the plug 100 while in the bore. Further, as can be seen in FIG. 4A, it is possible that the slip component halves 125a-b may not fully engage the casing 12. However, FIG. 4A shows that even if the slip component halves 125a-b do not fully engage the casing (12), the majority of the inserts 130 will still engage the casing 12. However, there may be many different variations of the engagement of the slip component 120 inserts 130 with the casing 12.

Referring to FIG. 4B, the slip component halves 125a-b have fully engaged the casing 12 after the slip component 120 has been compressed over its adjacent cone 106a. In this example, each of the inserts 130 have fully engaged the inner surface of the casing 12 in order to provide a flush connection with the casing 12. As further shown in FIG. 4B, the slip component 120 is fully fractured and expanded in order to provide adequate separation in order for the slip component halves 125a-b to fully engage the casing 12. Again, as described above, after the slip component 120 has shifted over the conical surface (107a) of the adjacent cone (106a), the slip component 120 will fracture or separate at the slits 124.

In the previous embodiment, only the uphole assembly 104a on the plug 100 included the disclosed slip component 120. This is not strictly necessary as will be appreciated herein. For example, FIG. 5 illustrates an elevational view of another plug 100 having two composite slip components 120 according to the present disclosure. As before, the plug 100 includes a mandrel 102 with the composite slip components 120 of the present disclosure disposed thereon. In this embodiment, the slip components 120 are disposed both at the upper end of plug 100 and at the lower end. In this embodiment, each of the slip components 120a-b also have slits 124 on either side. Also, the slip components 120a-b have insert holes 128 disposed around the surface as well as inserts 130 disposed within these holes 128.

In operation, the composite slip components 120a-b will shift over the conical surfaces 107a-b of the adjacent cones 106a-b until the slip components 120a-b expand, fracture, and fully engage the casing (12). Further as shown in FIG. 5, the conical surfaces 107a-b may have either a smooth conical surface (e.g., as shown by surface 107a) or may a series of flat surface (e.g., as shown by cone 107b). Either way, conical surfaces 107a-b serve similar purposes, i.e., to allow the slip components 120a-b to transition smoothly, expand, fracture, and engage the inner surface of the casing 12. Furthermore, as previously described, when plug 100 is actuated, the packing element 109 will expand and create a pressure seal within the casing 12.

In previous embodiments, the slip component 120 includes at least two slits 124, although other configurations are possible. For example, FIGS. 6A-6C illustrate an end view, a cross-sectional view, and a perspective view of another composite slip component 120 according to the present disclosure. As described above, the slip component 120 has a cylindrical body 122 with multiple insert holes 128 defined within its outer surface on a portion of its inner cylindrical surface 121. In this embodiment, it can be seen that slip component 120 only has one slit 124.

FIG. 6B shows a cross-sectional view of the slip component 120. As shown in this view, the slip component 120 includes the ramp 126 on the inner cylindrical surface 121. Functionality, the ramp 126 provides the slip component 120 an easier transition over the cones (106a-b) of plug (100). Further, FIG. 6B shows that the slip component 120 contains the insert holes 128 within the outer surface. The insert holes 128 can be disposed throughout the surface of the slip component 120 in a variety of different arrangements, depths, and or angles. Also, as described above, the insert holes 128 can have inserts (130) disposed within.

In reference to FIG. 6D, the slip component 120 is shown expanded within the casing 12, and has fully engaged the inner surface of the casing 12. In this embodiment, the one slit 124 on the cylindrical body 122 has fractured, allowing the slip component 120 to completely expand within the casing 12. As previously described, this is the result of the slip component 120 being compressed over the adjacent cone (106a-b) of plug 100. As seen, the outer cylindrical surface of the body 122 has fully engaged the casing 12, and each of the inserts 130 have been disposed against the casing 12.

The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. It will be appreciated with the benefit of the present disclosure that features described above in accordance with any embodiment or aspect of the disclosed subject matter can be utilized, either alone or in combination, with any other described feature, in any other embodiment or aspect of the disclosed subject matter.

In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.