WO2011025488A1

WO2011025488A1 - Casing shoe

Info

Publication number: WO2011025488A1
Application number: PCT/US2009/055193
Authority: WO
Inventors: Earl D. Webb; Dave D. Szarka; Jesse M. Baggett; Hank E. Rogers
Original assignee: Halliburton Energy Services, Inc.
Priority date: 2009-08-27
Filing date: 2009-08-27
Publication date: 2011-03-03

Abstract

A casing shoe (200), comprising a body (202), a nose (204) connected to the body, and at least one composite protrusion (206) attached to at least one of the body and the nose. A method of constructing a casing shoe, comprising preparing a surface (700) of at least one of a body and a nose of the casing shoe, covering at least a portion of the prepared surface with an injection mold (702), and injecting a composite material (708) into a space between the prepared surface and the injection mold.

Description

CASING SHOE

BACKGROUND

[0001] Wellbores are sometimes drilled into subterranean formations that contain hydrocarbons to allow recovery of the hydrocarbons. Some wellbore servicing methods employ casing strings that are lowered into a wellbore and the casing strings are sometimes at least partially cemented into position within the wellbore. The casing strings may comprise a casing shoe attached to a generally leading or lowermost portion of the casing string. The casing shoe may be used to guide the casing string past obstructions in the path of the casing string as the casing string is lowered into the wellbore. Further, casing shoes may comprise a generally cylindrical body attached to a tapered nose. Some casing shoes may comprise a float valve at least partially carried within one or both of the body and nose. Still further, some of the bodies and/or noses may include protrusions that assist in guiding the casing string past obstructions as the casing string is lowered into the wellbore.

[0002] Once formed and/or joined to the bodies and/or noses, some of the above-mentioned protrusions may be enhanced with relatively hard cutting features. Such cutting features may assist in cutting, breaking through, drilling out, and/or otherwise overcoming an obstruction as the casing string is lowered into the wellbore. However, current systems and methods for providing cutting features to a casing shoe are time consuming, expensive, and sometimes damage the components of the casing shoe. For example, while tungsten carbide may be welded onto a body and/or nose of a casing shoe, the application of the tungsten carbide through the welding process is time consuming and cannot reliably produce multiple cutting features having substantially the same physical geometry. Further, the welding process may weaken the body and/or the nose to which the cutting features are added. Accordingly, there exists a need for improved casing shoes and improved methods of constructing casing shoes. SUMMARY

[0003] Disclosed herein is a casing shoe, comprising a body, a nose connected to the body, and at least one composite protrusion attached to at least one of the body and the nose.

[0004] Also disclosed herein is a method of constructing a casing shoe, comprising preparing a surface of at least one of a body and a nose of the casing shoe, covering at least a portion of the prepared surface with an injection mold, and injecting a composite material into a space between the prepared surface and the injection mold.

[0005] Further disclosed herein is a method of constructing a casing shoe, comprising providing an injection mold for forming at least one of a nose of the casing shoe and a body of the casing shoe, attaching at least one cutter to an interior wall of the injection mold, with the exception of at least one bleed aperture and at least one input port, substantially sealing an internal space of the injection mold, and injecting a composite material into the internal space so that the cutter is at least partially embedded within the composite material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description:

[0007] Figure 1 is a cut-away view of an embodiment of a wellbore servicing system according to an embodiment;

[0008] Figure 2 is an oblique view of a casing shoe according to an embodiment;

[0009] Figure 3 is an oblique view of a casing shoe according to another embodiment;

[0010] Figure 4 is a cross-sectional view of the casing shoe of Figure 3;

[0011] Figure 5 is an oblique view of a casing shoe according to another embodiment; [0012] Figure 6 is an oblique view of a casing shoe according to another embodiment;

[0013] Figure 7 is an oblique view of a casing shoe according to another embodiment;

[0014] Figure 8A is a partial simplified cut-away view of a first step of constructing a casing shoe;

[0015] Figure 8B is a partial simplified cut-away view of a second step of constructing the casing shoe of Figure 8A;

[0016] Figure 8C is a partial simplified cut-away view of a third step of constructing the casing shoe of Figure 8A;

[0017] Figure 8D is a partial simplified cut-away view of a fourth step of constructing the casing shoe of Figure 8A;

[0018] Figure 8E is a partial simplified cut-away view of a fifth step of constructing the casing shoe of Figure 8A; and

[0019] Figure 8F is a partial simplified cut-away view of a sixth step of constructing the casing shoe of Figure 8A.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] In the drawings and description that follow, like parts are typically marked throughout the specification and drawings with the same reference numerals, respectively. The drawing figures are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness.

[0021] Unless otherwise specified, any use of any form of the terms "connect," "engage," "couple," "attach," or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements and may also include indirect interaction between the elements described. In the following discussion and in the claims, the terms "including" and "comprising" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to ...". Reference to up or down will be made for purposes of description with "up," "upper," "upward," or "upstream" meaning toward the surface of the wellbore and with "down," "lower," "downward," or "downstream" meaning toward the terminal end of the well, regardless of the wellbore orientation. The term "zone" or "pay zone" as used herein refers to separate parts of the wellbore designated for treatment or production and may refer to an entire hydrocarbon formation or separate portions of a single formation such as horizontally and/or vertically spaced portions of the same formation. The various characteristics mentioned above, as well as other features and characteristics described in more detail below, will be readily apparent to those skilled in the art with the aid of this disclosure upon reading the following detailed description of the embodiments, and by referring to the accompanying drawings.

[0022] Referring to Figure 1, an example of a cased wellbore operating environment is shown. As depicted, the operating environment comprises a drilling rig 106 that is positioned on the earth's surface 104 and extends over and around a wellbore 114 that penetrates a subterranean formation 102 for the purpose of recovering hydrocarbons. The wellbore 114 may be drilled into the subterranean formation 102 using any suitable drilling technique. The wellbore 114 extends substantially vertically away from the earth's surface 104 over a vertical wellbore portion 116, deviates from vertical relative to the earth's surface 104 over a deviated wellbore portion 136, and transitions to a horizontal wellbore portion 118. In alternative operating environments, all or portions of a wellbore may be vertical, deviated at any suitable angle, horizontal, and/or curved. [0023] A casing string 120 comprising casing shoe 200 is lowered into the subterranean formation 102 in a conventional manner and may subsequently be secured within the wellbore 114 by filling an annulus 112 between the casing string 120 and the wellbore 114 with cement. In alternative operating environments, a horizontal wellbore portion may be cased and cemented and/or portions of the wellbore may be uncased. The drilling rig 106 comprises a derrick 108 with a rig floor 110 through which the casing string 120 extends downward from the drilling rig 106 into the wellbore 114. The drilling rig 106 comprises a motor driven winch and other associated equipment for extending the casing string 120 into the wellbore 114 to position the casing shoe 200 at a selected depth.

[0024] While the operating environment depicted in Figure 1 refers to a stationary drilling rig 106 for lowering and setting the casing string 120 and casing shoe 200 within a land-based wellbore 114, in alternative embodiments, mobile workover rigs, wellbore servicing units (such as coiled tubing units), and the like may be used to lower the casing string 120 and casing shoe 200 into a wellbore. It should be understood that a casing string 120 and casing shoe 200 may alternatively be used in other operational environments, such as within an offshore wellbore operational environment.

[0025] Regardless of the type of operational environment the casing shoe 200 is used, it will be appreciated that the casing shoe 200 serves to aid in guiding the casing string 120 through the wellbore 114. As described in greater detail below, the casing shoe 200 comprises a body 202 and a tapered nose 204 attached to the body 202. In this embodiment, the body 202 carries protruding vanes 206 that serve to both centralize the casing shoe 200 within the wellbore 114 and to remove obstructions in the path of the casing shoe 200 as the casing shoe 200 is moved into position within the wellbore 114. The tapered nose 204 also serves to guide the casing shoe 200 past obstructions. It will be appreciated that the obstructions may be ledges which form in the wellbore 114 while boring the wellbore 114, formation washouts, debris from unstable sections of the wellbore 114 wall collapsing, or any other matter native to the wellbore 114. It will further be appreciated that other obstructions may be objects or debris foreign to the wellbore 114 that were introduced to the wellbore 114, accidentally or purposefully, during creation and/or treatment of the wellbore 114. It will be appreciated that casing shoe 200 may also be referred to by some as a "reamer shoe" at least in part because the casing shoe 200 may be rotated generally about a central axis 208 of the casing shoe 200 or reciprocated along the length of the wellbore 114 (e.g., up and down) to remove and/or pass the above-described obstructions.

[0026] Referring now to Figure 2, the casing shoe 200 is shown in greater detail. As explained above, casing shoe 200 comprises a central axis 208. In this embodiment, the body 202 comprises a generally cylindrical tubular shape having a threaded fitting 210 sized and shaped to connect to the casing string 120 in a conventional manner. The body 202 further comprises a reduced outer diameter neck 212 that extends from the fitting 210. In this embodiment, the body 202 is constructed of steel and is formed as a unitary piece by conventional methods such as casting and/or machining. The neck 212 is further configured to connect to the nose 204 in a conventional manner. For example, the neck 212 may comprise threads for receiving complementary threads of the nose 204. It will be appreciated that in some embodiments, the body 202 and nose 204 comprise an internal bore 214 that extends generally along the central axis 208 and may be used to transmit fluid therethrough. Further, in this embodiment, the casing shoe 200 comprises lateral apertures 216 that extend at least partially radially from an exterior of the nose 204 to the bore 214. [0027] The casing shoe 200 further comprises a plurality of vanes 206 that extend generally along the longitudinal length of the neck 212. It will be appreciated that vanes 206 may be referred to as "protrusions" since the vanes 206 protrude from an outer surface of the neck 212. Similarly throughout this disclosure, other components and/or elements formed at least partially of composite material (where the composite material, in some embodiments, may be at least partially injectable at least during the formation of the protrusions) that are attached to, carried by, or are otherwise associated with a casing shoe (e.g., casing shoe 200) may be referred to as "protrusions" where the other components and/or elements generally extend outward from an exterior surface of the casing shoe. Accordingly, a "composite protrusion" may refer to any component and/or element (e.g., a vane) that comprises a composite material and which generally extends from an exterior surface of a casing shoe. Vanes 206 each generally comprise a base layer 218 and a cutting layer 220. It will be appreciated that the base layer 218 comprises primarily a composite material while the cutting layer 220 further comprises relatively harder cutting elements disposed within the composite material.

[0028] In some embodiments, the composite material may comprise a ceramic based resin, for example, but not limited to, the types disclosed in U.S. Patent Application Publication Nos. US 2005/0224123 Al, entitled "Integral Centraliser" and published on October 13, 2005, and US 2007/0131414 Al, entitled "Method for Making Centralizers for Centralising a Tight Fitting Casing in a Borehole" and published on June 14, 2007. For example, in some embodiments, the resin material may include bonding agents such as an adhesive or other curable components. In some embodiments, components to be mixed with the resin material may include a hardener, an accelerator, or a curing initiator. Further, in some embodiments, a ceramic based resin composite material may comprise a catalyst to initiate curing of the ceramic based resin composite material. The catalyst may be thermally activated. Alternatively, the mixed materials of the composite material may be chemically activated by a curing initiator. More specifically, in some embodiments, the composite material may comprise a curable resin and ceramic particulate filler materials, optionally including chopped carbon fiber materials. In some embodiments, a compound of resins characterized by a high mechanical resistance, a high degree of surface adhesion and resistance to abrasion by friction, and an elasticity of the compound in a final form may be higher than the elasticity of the casing shoe components to which it is attached.

[0029] In some embodiments, the composite material may be provided prior to injection and/or molding as separate two-part raw material components for admixing during injection and/or molding and whereby the whole can be reacted. The reaction may be catalytically controlled such that the various components in the separated two parts of the composite material will not react until they are brought together under suitable injection and/or molding conditions. Thus, one part of the two-part raw material may include an activator, initiator, and/or catalytic component required to promote, initiate, and/or facilitate the reaction between the whole mixed composition. In some embodiments, the appropriate balance of components may be achieved in a mold by use of pre-calibrated mixing and dosing equipment.

[0030] It will be appreciated that any other suitable material may be used in other embodiments where such other materials allow for the creation of substantially similar vane 206 structures and where the material properties are consistent with commonly accepted uses of reamer shoes and/or casing shoes. For example, in some embodiments, the composite material may comprise carbon fiber and/or any other discrete structural elements disposed within an epoxy and/or any other suitable selectively hardenable material that may be injected prior to hardening. Further, in this embodiment, the cutting elements may comprise tungsten carbide, natural or synthetic diamond (e.g., industrial grade diamonds, bort, etc.), tool steel fabricated inserts, or any other suitably hard material for degrading obstructions encountered by the cutting elements. In this embodiment, the cutting elements comprise crushed and/or granulated tungsten carbide.

[0031] In some embodiments, the vanes 206 may have substantially constant widths and/or thicknesses of base layers 218 and cutting layers 220. In alternative embodiments, the vanes 206 may have varying widths and/or thicknesses of base layers 218 and cutting layers 220. In an embodiment, the vanes 206 each comprise a leading side 222 and a trailing side 224, with leading side generally referring to the direction of rotation about the central axis 208 (e.g., clockwise rotation). As shown in Figure 2, the thickness of layers 218, 220 may vary from the leading side 222 to the trailing side 224. For example, the thickness of the cutting layer 220 is greater at the leading side 222 as compared to the thickness of the cutting layer 220 at the trailing side 224. In this embodiment, the thickness of the cutting layer 220 generally decreases in a linear manner across the width of a vane 206. Conversely, the thickness of the base layer 218 is less at the leading side 222 as compared to the thickness of the base layer 218 at the trailing side 224. In this embodiment, the thickness of the base layer 218 generally increases in a linear manner across the width of a vane 206. Further, in this embodiment and with the exception of tapered ends 226, the overall height of vanes 206 (i.e., the distance the vanes radially protrude away from the neck 212 as represented by the combined thickness of the base layer 218 and the cutting layer 220) is substantially constant. It will be appreciated that providing such a thicker cutting layer 220 near a leading side 222 may be advantageously employed by rotating the casing shoe 200 about the central axis 208 so that the leading side 222 of a vane 206 is first to encounter an obstruction as compared to a time when a trailing side 224 of the same vane 206 encounters the obstruction. As such, by rotating the casing shoe 200 in the above-described manner, obstructions may be removed by the casing shoe 200 and the casing shoe 200 may exhibit a longer service life as compared to rotating the casing shoe 200 in a reverse manner. Finally, it will be appreciated that during longitudinal reciprocation of the casing shoe 200, the tapered ends 226 may provide enhanced obstruction removal and may limit damage to the vanes 206. Likewise, the thickness of the cutting layer 220 may be increased at the downhole tapered ends 226 (e.g., those closest to the nose 204) in comparison to the thickness of the uphole tapered ends (e.g., those closest to the threaded fitting 210) to extend service life of the leading edges of the vanes coming into contact with obstructions during longitudinal reciprocation of the casing shoe.

[0032] Referring now to Figures 3 and 4, a casing shoe 200 similar to that of Figure 2 is shown with an alternative embodiment of a vane 300 (a composite protrusion) that is substantially similar in function to vane 206 of Figure 2. However, rather than comprising various layers in the manner shown in vane 206 of Figure 2, vane 300 of Figures 3 and 4 comprises a single base layer 218 that is formed around cutter elements 302. In the embodiment of Figure 2, cutter elements 302 are formed substantially as solid cylinders. However, in alternative embodiments, cutter elements 302 may comprise any other suitable shape. It will be appreciated that in some embodiments, the vanes 300 may be formed according to a method so that the cutter elements are held in place as the base layer 218 is formed around the cutter elements 302 so that the cutter elements 302 are fixed in their location at the time of forming the base layer 218. In this embodiment, the cutter elements 302 are shown as extending radially from the neck 212 and beyond the exterior of the vane 300. However, it will be appreciated that in alternative embodiments, the cutter elements 302 may not extend so fully through the base layer 218, that is base layer 218 may extend under cutter elements 302 and obstruct complete or partial contact of cutter elements 302 with neck 212. For example, an adhesive layer may be placed between cutter elements 302 and neck 212, thereby adhering cutter elements 302 to neck 212, and base layer 218 may be further disposed and formed about the adhered cutter elements 302 to form vanes 300. It will be appreciated that the cutter elements 302 are constructed of tungsten carbide in an embodiment, and in alternative embodiments, the cutter elements 302 may be constructed of any other suitable material or combination of materials.

[0033] Referring now to Figure 5, an alternative embodiment of a casing shoe 400 is shown. The casing shoe 400 comprises a substantially cylindrical tubular body 402 connected to a substantially frusto-conical tubular nose 404. In this embodiment, vanes 300 of the type shown in Figures 3 and 4 are attached to the nose 404 so that lower most tapered ends 226 extend to near a tip end 406 of nose 404. In an alternative embodiment, vanes 300 of Figure 5 are replaced with layered vanes 206 of the type shown in Figure 2. It will be appreciated that in an embodiment, the nose 404 is constructed of aluminum but that in alternative embodiments, the nose 404 may be constructed of any other suitable material (e.g., a drillable material, consumable material, degradable material, etc.).

[0034] Referring now to Figure 6, a casing shoe 200 is shown as comprising vanes 500 (protrusions) according to an alternative embodiment. Vanes 500 are substantially similar in form and function to vanes 206 of Figure 2 and/or vanes 300 of Figures 3 and 4, however, the vanes 500 do not simply extend longitudinally along the length of neck 212. Instead, vanes 500 each generally comprise an extended "S" shape that meanders along the neck 212 about the central axis 208. The vanes 500 are angularly spaced about the surfaces of the neck 212 so that corresponding "S" shaped channels 502 are formed between adjacent vanes 500. Vanes 500 further comprise tapered ends 226. Further, the upper and lower ends of the vanes 500 are oriented generally parallel to the central axis 208. Accordingly, the vanes 500 may be advantageously utilized by longitudinally reciprocating the casing shoe 200 to remove obstructions in a manner that simple reciprocation of vanes 206, 300, could not otherwise achieve without rotation of casing shoe 200 about central axis 208.

[0035] Referring now to Figure 7, a reamer shoe or casing shoe 600 substantially similar to the reamer shoe disclosed in European Patent No. EP 1235971 Bl (which is hereby incorporated by reference in its entirety) is shown. Casing shoe 600 comprises a body 602, a reaming area 604 comprising diamond shaped tungsten carbide reaming members 606 (protrusions), centralizers 608, flow ports 612, and an eccentrically shaped nose 614. In an embodiment, the reaming members 606 and/or the centralizers 608 are arranged to provide fluid flow channel along the outside surface of the reamer shoe. It will be appreciated that one or more of the centralizers 608 and/or the reaming members 606 may be constructed according to any of the methods described herein. For example, the reaming members 606 and/or the centralizers 608 may comprise base layers 218 and cutting layers 220 of vanes 206 in Figure 2 and/or cutter elements 302 and base layer 218 of vanes 300 of Figures 4 and 5.

[0036] Referring now to Figures 8A-8F, a method of constructing a casing shoe is shown. One or more of the above-described embodiments of a casing shoe may be constructed according to the description below. First, with reference to Figure 8A, an attachment surface 700 of the casing shoe (e.g., outer surface of the neck and/or outer surface of the nose) may be prepared for attachment of a protrusion/projection (e.g., vane, reaming member, centralizer, etc.) thereto. In an embodiment, the attachment surface is metallic, for example steel. In some embodiments, the attachment surface 700 may be corrugated, stippled, or otherwise roughened to more easily bond to a composite resin material. Next, an injection mold 702 configured suitably to provide the shape of a projection/protrusion (e.g., vane, reaming member, centralizer, etc.) may be provided with an adhesive 704 on an interior surface of the mold 702. Next, cutting elements 706 may be introduced to the adhesive 704 so that the cutting elements 706 are releasably adhered to and move substantially in unison with the mold 702.

[0037] Referring now to Figure 8B, the mold 702 may be moved into a closer relationship with (e.g., proximate or adjacent to) the attachment surface 700 and generally be sealed against the attachment surface 700. Following such generally sealing against the attachment surface 700, a base layer material 708 (e.g., the above-described ceramic based resin material) may be introduced into a space between the mold 702 and the attachment surface 700. For example, the base layer 708 may flow about and form a coating layer on attachment surface 700, while leaving an open space between the base layer 708 and the interior surface of the mold 702 where the volume of base layer material introduced is less than the volume of void space between the mold

702 and the attachment surface 700.

[0038] Referring now to Figure 8C, in embodiments where the mold 702 is provided with an external access door 710, the door 710 may be opened and further cutting elements 706 may be introduced into the space between the mold 702 and the attachment surface 700, for example embedded with the base layer 708.

[0039] Referring now to Figure 8D, with the door 710 open, an adhesive 704 may be present and/or attached to an inside surface of the door 710 and cutter elements 706 may be introduced to the adhesive 704 that is attached to the door 710.

[0040] Referring now to Figure 8E, the door 710 may be closed and sealed. Subsequently, additional base layer material 708 may be introduced to the space between the mold 702 and the attachment surface 700. Such amount of material may be equal to or less than an amount of fill the void space between the mold 702 and the attachment surface 700, and may be selected to leave a desired about of cutter elements 706 exposed.

[0041] Referring now to Figure 8F, after the base layer material 708 has sufficiently hardened and/or set, the mold 702 may be unsealed from the casing shoe. As the mold 702 is moved away from the attachment surface 700, the adhesive 704 (e.g., double sided tape in some embodiments) is released/disconnected from the cutter elements 706, leaving them at least partially embedded within the hardened base layer material 708. It will be appreciated that the adhesive 704 and other adhesives described in this disclosure may comprise any suitable material or device, including, but not limited to, tapes, glues, and/or hardenable materials such as room temperature vulcanizing silicone. In an embodiment, some of the cutter elements 706 extend a substantially equal radial distance from the attachment surface 700, for example forming a unitary surface layer 711 as shown in Figure 8F. Alternatively or additionally, some of the cutter elements may be distributed throughout the entire thickness of the base layer as shown by cutter element group 712 of Figure 8F. The cutter element group 712 shows both fully embedded and partially embedded cutter elements.

[0042] It will be appreciated that in an embodiment, cutter elements 706 comprise tungsten carbide that has been crushed to a gravel-like state while cutter element 706' is a substantially cylindrical tungsten carbide structure. Further, cutter element 706' comprises a reduced cross- sectional area 720 located at least partially further away from the attachment surface 700 as compared to a lower larger cross-sectional area 722. Such positioning of the cross-sectional areas 720, 722 may provide enhanced securing of the cutter element 706' within the base layer material 708. As shown in Figure 8, the length of the cutter element 706' may be selected such that base layer material 708 prevents direct contact with the attachment surface 700. Alternatively, the length of the cutter element 706' may be selected such that the cutter element is in direct contact with the attachment surface 700 and/or the cutter element 706' may be forced into direct contact, for example during placement via door 710. It will be appreciated that the various aspects of the method of forming the projection/protrusion may be selected to achieve the desired combination and layout of the base layer material 708 and cutter elements 706 as described herein (e.g., various combinations of cylindrical cutter elements 706', surface layers 711, and/or cutter element groups 712 to form vanes, reaming members, centralizers, etc. as described herein).

[0043] It will be appreciated that in alternative embodiments, combinations of the above- described casing shoe bodies, noses, vanes, and/or protrusions may be singularly formed in a unitary manner through an injection molding process using a composite material. For example, a nose of a casing shoe may be formed of composite material at the same time composite protrusions are formed integrally on that nose. Similarly, a body of a casing shoe may be formed of composite material at the same time composite protrusions are formed integrally on that body. Still further, an entire casing shoe may be formed of composite material so that composite protrusions are formed on one or both of the body and nose of that casing shoe. Of course, one or more of the above-described bodies, noses, and/or protrusions may be configured to retain cutter elements (such as but not limited to cutter elements 706) in any one of the above-described manners.

[0044] Such integral and unitary formation of casing shoes and/or casing shoe components through injection molding may be accomplished according to the following method. First, an injection mold may be provided that has appropriate internal geometry for forming at least one of a nose of the casing shoe and a body of the casing shoe. Next, a cutter and/or cutter elements may be placed within the injection mold. It will be appreciated that the cutter and/or cutter elements may be loosely carried within the injection mold and/or the cutter and/or cutter elements may be attached to an interior wall of the injection mold. With the cutter and/or cutter elements in place within the injection mold, the internal space of the injection mold may be sealed off except to leave at least one input port open and at least one bleed aperture open. The input port serves to allow introduction of composite material into the internal space of the injection mold while the bleed aperture allows fluid and/or material displaced by the injected composite material to escape the internal space of the injection mold. The bleed aperture may also be used to allow passage of excess injected composite material. During the injection of the composite material, the cutter and/or cutter elements become at least partially embedded within the composite material.

[0045] In this manner bodies, noses, protrusions and/or other components of casing shoes may be formed around or placed concurrently with the cutters and/or cutting elements. Of course, in some embodiments, the injection mold may be shaped to provide protrusions extending from the body and/or nose of the casing shoe. In other words, through the use of appropriately shaped injection molds and by placing cutters and/or cutter elements within the injection mold and filling the mold with composite material around the cutters and/or cutter elements, any of the above-described casing shoes may be formed integrally in an injection mold process. It will further be appreciated that cutters and/or cutter elements may also be introduced into the interior space of the injection mold after some composite material has been introduced into the interior space of the injection mold.

[0046] At least one embodiment is disclosed and variations, combinations, and/or modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of the disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, R₁, and an upper limit, R_u, is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=Ri+k*(R_u-Ri), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, ..., 50 percent, 51 percent, 52 percent, ..., 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed. Use of the term "optionally" with respect to any element of a claim means that the element is required, or alternatively, the element is not required, both alternatives being within the scope of the claim. Use of broader terms such as comprises, includes, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above but is defined by the claims that follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present invention.

Claims

CLAIMS What is claimed is:

1. A casing shoe, comprising:

a body;

a nose connected to the body; and

at least one composite protrusion attached to at least one of the body and the nose.

2. The casing shoe according to claim 1, further comprising:

a cutter at least partially embedded within the at least one composite protrusion.

3. The casing shoe according to claim 2, wherein the cutter is fully embedded within the at least one composite protrusion.

4. The casing shoe according to claim 2, wherein the cutter substantially extends from an outer surface of at least one of the body and the nose.

5. The casing shoe according to claim 2, wherein the cutter comprises a reduced cross- sectional profile and a larger cross-sectional area, the reduced cross-sectional area being at least partially located further from an outer surface of at least one of the body and the nose than the larger cross-sectional area.

6. The casing shoe according to claim 2, wherein a plurality of cutters are disposed to extend a substantially equal distance from an outer surface of at least on of the body and the nose.

7. The casing shoe according to claim 2, wherein the cutter comprises tungsten carbide.

8. The casing shoe according to claim 1, wherein the at least one composite protrusion comprises a ceramic based resin.

9. The casing shoe according to claim 1, wherein the at least one protrusion is formed integrally with the nose.

10. The casing shoe according to claim 1, wherein the body, the nose, and the at least one protrusion are formed integrally.

11. A method of constructing a casing shoe, comprising:

preparing a surface of at least one of a body and a nose of the casing shoe;

covering at least a portion of the prepared surface with an injection mold; and

injecting a composite material into a space between the prepared surface and the injection mold.

12. The method of claim 11 , further comprising:

introducing a cutter into the space prior to fully filling the space with the composite material.

13. The method of claim 12, wherein the cutter is carried by the injection mold during at least a portion of the injecting of the composite material.

14. The method of claim 13, wherein the cutter is attached to the injection mold by a removable adhesive.

15. The method of claim 11, wherein the cutter is introduced into the space after some composite material is injected into the space and wherein the cutter is passed into the space through an opening in the injection mold.

16. A method of constructing a casing shoe, comprising:

providing an injection mold for forming at least one of a nose of the casing shoe and a body of the casing shoe;

attaching at least one cutter to an interior wall of the injection mold;

with the exception of at least one bleed aperture and at least one input port, substantially sealing an internal space of the injection mold; and

injecting a composite material into the internal space so that the cutter is at least partially embedded within the composite material.

17. The method of claim 16, wherein at least one of the cutter elements is introduced subsequent the injecting of the composite material.

18. The method of claim 16, wherein at least one of the cutter elements comprises tungsten carbide.

19. The method of claim 16, wherein the composite material comprises a ceramic based resin.