Abstract: A sensor device can be used to detect the presence of a cement composition in a reverse cementing operation. The sensor device can include a resistivity sensor, an acquisition and measurement apparatus, and an actuator. The actual derivative of resistivity of the drilling mud, spacer fluid, and cement composition to be used can be pre-determined. The acquisition and measurement apparatus can be pre-programmed with a slope change derivative of resistivity profile for the fluids. The resistivity sensor can measure the resistivity of the fluids as they flow past the resistivity sensor in the wellbore. When the acquisition and measurement apparatus receives a desired slope change reading within the slope change derivative of resistivity profile, instructions can be sent to the actuator to close a valve and block fluid flow through the casing or tubing string.

Abstract: A float valve is used in a tubular having a through-bore for flow. The tubular can be a casing joint, a casing pup joint, a housing or a shell of a float collar/shoe, or other tubular element. A sleeve of drillable material is expanded inside the tubular. Sealing and/or anchor elements on the exterior of the sleeve can engage inside the tubular. Caps composed of drillable material are disposed on ends of the sleeve and have passages connected to ends of a flow tube. The flow tub is also composed of drillable material and has a bore therethrough for flow. A valve composed of drillable material is disposed in the passage of one of the caps and is configured to control the flow in the tubing through the flow tube.

Abstract: A well tool attachment includes a tubular body with a bore therethrough extending along a longitudinal axis, wherein the tubular body is configured to seat in a shoe track of a well casing. A plurality of partitions are suspended from the tubular body, dividing the bore of the tubular body into a plurality of segments extending axially through the tubular body. The partitions are configured to break up cement slurry entering the bore of the tubular body into a plurality of cement segments to facilitate drilling after downhole cement sets.

Abstract: A method and apparatus for preventing fluid flow and contamination to a cement body includes a resin cap covering an exposed end of the cement body. The cement body may attach an inner sleeve to an outer sleeve. The fluid flowing through the outer sleeve is prevented from contacting the exposed surface by the resin cap. Resin caps at both ends of the cement body along with resin layers along the side may be included. The resin prevents contamination and creation of micro-annuli in the cement body.

Abstract: Downhole tools, methods, and systems of use thereof, the downhole tools comprising at least one component made of a doped alloy that at least partially degrades by micro-galvanic corrosion in the presence of fresh water having a salinity of less than about 1000 ppm, and wherein the doped alloy is selected from the group consisting of a doped magnesium alloy, a doped aluminum alloy, and any combination thereof.

Abstract: Embodiments of the invention relate to methods of making articles having portions of polycrystalline diamond bonded to a surface of a substrate and polycrystalline diamond compacts made using the same. In an embodiment, a molding technique is disclosed for forming cutting tools comprising polycrystalline diamond portions bonded to the outer surface of a substrate.

Abstract: A modular fracture plug and method of construction thereof for temporarily sealing off a well is provided. The fracture plug includes an inner substrate material and an outer shell. The outer shell is provided having a plurality of individual sections bonded to one another. One of the sections provides a closed base, while another of the sections provides a closed cover, and one or more of the sections provide an intermediate section between the base and the cover. The intermediate section has a through opening forming at least a portion of the cavity.

Abstract: A drill bit assembly has a bit head and a pin body. The bit head comprises a cutting end, an opposite connecting end with an engagement section, and a feature facing the connecting end. The pin body comprises a tubular body with an axial bore therethrough, a connecting end with an engagement section and a feature facing the connecting end. The drill bit assembly is manufactured by positioning the pin body connecting end with the bit head connecting end such that the pin body and bit head engagement sections overlap with a gap therebetween, and the pin body and bit head features are aligned; injecting a thermoplastic or other connecting material in liquid form between the bit head and pin body engagement sections and into the gap; and solidifying the thermoplastic or other connecting material such that the bit head and pin body are mechanically coupled together at their connecting ends and their features are securely aligned.

Abstract: An anvil or mule shoe of a downhole tool disposable in a casing of an oil or gas well includes a scoop formed in a bottom of the downhole tool with a concave profile oriented at an acute angle with respect to a longitudinal axis of the downhole tool and extending across a majority of the bottom; and/or a plurality of helical flutes formed in an exterior of the anvil of the downhole tool and extending circumferentially and helically around the longitudinal axis of the downhole tool.

Abstract: A jet pump mounts on a pipe string in a well passing through coal beds. The pipe string length is greater than the lower coal bed occurrence depth. A carrying ring, with filtering shoe attached on a switcher, mounts below the lower bed floor. A carrying ring with bypass ports mounts on the string above the upper bed roof. A packer mounts on the string below the ports above the upper bed roof. A pump housing with a removable insert seat, having a nozzle and a mixing chamber with diffuser, mounts on the ring. The housing has a working fluid and exhausted fluid mixture draining channel and an exhausted fluid supplying channel, provided with a check valve. The housing connects to a working fluid supply pipe provided on the upper end with a sealing element disposed on the ring, and an inlet funnel receiving the removable insert.

Abstract: Earth-boring casing shoes include a crown configured for at least one of drilling and reaming a wellbore when the crown is attached to a section of casing and the casing is advanced into a wellbore. The crown includes a body comprising a corrodible composite material, and at least one cutting structure carried on the body. The casing shoes further include a connection structure configured for attachment to a section of casing. Methods are used to form such casing shoes, and such casing shoes are used to install casing within wellbores.

Abstract: A tool string disposed in at least one tubular having upper and lower threaded connections to connect to a drill string. The tool string includes a shock reduction tool, which includes an anchoring tail piece axially and rotationally fixed to the at least one tubular. A universal bore hole orientation (UBHO) muleshoe sub is disposed at an upper end of the shock reduction tool. A downhole electronics package coupled to the UBHO muleshoe sub.

Abstract: A reaming shoe for location in a bore has a rotationally balanced nose. A rotary drive is rotationally coupled to the reaming shoe to enable reaming of the bore. The assembly of the reaming shoe and the rotary drive is adapted to be coupled to a tubular component. The reaming shoe is mounted to the tubular component to enable rotation of the reaming shoe independently of the tubular component, such that the reaming shoe is rotatable at a different rotational speed than the tubular component.

Abstract: Apparatus for running a casing string into a wellbore features a housing arranged for coupling to the casing string in fluid communication with an interior thereof, a shoe rotatably supported at a lower end of the housing, and a drive mechanism. The drive mechanism features a shaft extending internally along the housing toward the upper end thereof from a connection of the shaft to the shoe, and a ribbon coiling around and along the shaft toward the shoe in a manner radially spaced from the shaft above the connection thereof to the shoe. The ribbon drive rotations of the shaft through action of a fluid on said ribbon under pumping of said fluid through the housing from the casing. The drive mechanism thus employs a simple structure of a rotor assembly spinning within the housing, without requiring an additional stator or housing-carried vanes.

Abstract: An earth removal member for drilling a wellbore with casing or liner includes a tubular body and a head. The head is fastened to or formed with an end of the body, has a face and a side, is made from a high strength material, and has a port formed through the face. The earth removal member further includes a blade. The blade is formed on the head, extends from the side and along the face, and is made from the high strength material. The earth removal member further includes cutters disposed along the blade; and a nozzle adapter. The nozzle adapter has a port formed therethrough, is longitudinally and rotationally coupled to the head, and is made from a drillable material. The earth removal member further includes a nozzle disposed in the adapter port and fastened to the nozzle adapter.

Abstract: Provided is a shoe for wellbore lining tubing and to a method of locating wellbore lining tubing in a wellbore. In particular, but not exclusively, the present invention relates to a shoe for wellbore tubing having an improved fluid flow diverter assembly for controlling circulation of fluid in the wellbore.

Abstract: A method and apparatus for completing a horizontal hydrocarbon well includes cementing a casing string in the well and creating passages through the casing string adjacent float equipment near the casing toe by slowly dissolving a plug with completion fluid used to pump cement into an annulus between the casing string and bore hole. By the time the cement sets up, the plug dissolves leaving passages in the casing string through which a first frac job may be pumped or which allows pumping perforating equipment into the horizontal leg without requiring a coiled tubing run. The technique can also be used in vertical wells to save a perforating gun run.

Abstract: Casing shoes comprise a nose portion having an inner profile and an outer profile. At least one cutting structure is on the outer profile. A stem section extends longitudinally from the nose portion. At least one of a float valve mechanism, a cementing stage tool, a float collar mechanism, and a landing collar structure is disposed within the stem section. Methods of installing sections of casing within wellbores comprise advancing the at least one section of casing into contact with subterranean formation material with a casing shoe attached thereto. At least one of a float valve mechanism, a cementing stage tool, a float collar mechanism, and a landing collar structure is carried within the casing shoe into the wellbore. The wellbore is drilled or reamed using at least one cutting structure on the casing shoe as the at least one section of casing is advanced into the wellbore.

Abstract: A damping and sealing device for enabling gas or liquid flow from a well to a production tube in the well, including a body with a flow passage internal to the body and a spring disposed about a portion of the body. The flow passage includes a first opening at a first longitudinal end of the body and a second opening at a second longitudinal end of the body. The first end is arranged to contact a plunger for the well and the body is arranged to sealingly engage the production tube. In one embodiment, the body includes an inner circumferential surface and an outer circumferential surface, the inner circumferential surface forms the internal flow passage, and a portion of the outer circumferential surface is arranged to slide along a portion of the inner circumferential surface in response to the first end contacting a plunger.

Abstract: A casing bit, which may comprise a composite structure, for drilling a casing section into a subterranean formation, and which may include a portion configured to be drilled therethrough, is disclosed. Cutting elements and methods of use are disclosed. Adhesive, solder, electrically disbonding material, and braze affixation of a cutting element are disclosed. Differing abrasive material amount, characteristics, and size of cutting elements are disclosed. Telescoping casing sections and bits are disclosed. Aspects and embodiments are disclosed including: at least one gage section extending from a nose portion, at least one rotationally trailing groove formed in at least one of a plurality of blades, a movable blade, a leading face comprising superabrasive material, at least one of a drilling fluid nozzle and a sleeve, grooves for preferential failure, at least one rolling cone affixed to the nose portion, at least one sensor, discrete cutting element retention structures, and percussion inserts.

Abstract: A tubing shoe is disclosed with a body adapted to be connected to a section of tubing to be emplaced in a wellbore and a nose provided on the body, wherein the nose includes a failure guide structure for controlling break-up of the nose upon being drilled out from inside the nose. The failure guide structure typically controls break up by limiting the maximum size of pieces of the nose broken off upon drill out, for example, by defining weakened areas of the nose which are prone to failure upon drilling. The failure guide structure can include discontinuities such as slots or bores formed or drilled into the outer surface of the nose. The failure guide structure controls the break up of the nose in a consistent and predictable manner, and typically at a predictable stage during the drill-out process.

Abstract: Embodiments of the present invention generally relate to an earth removal member with features for facilitating drill-through. In one embodiment, an earth removal member for drilling a wellbore with casing or liner includes a tubular body and a head. The head is fastened to or formed with an end of the body, has a face and a side, is made from a high strength material, and has a port formed through the face. The earth removal member further includes a blade. The blade is formed on the head, extends from the side and along the face, and is made from the high strength material. The earth removal member further includes cutters disposed along the blade; and a nozzle adapter. The nozzle adapter has a port formed therethrough, is longitudinally and rotationally coupled to the head, and is made from a drillable material. The earth removal member further includes a nozzle disposed in the adapter port and fastened to the nozzle adapter.

Abstract: Embodiments of the invention relate to an assembly for forming a cased well. The assembly may include an undercut drillable cementing shoe with a casing string connection at a first end. The shoe includes external tubing that forms a second end of the shoe and has a first section defining an enlarged inner diameter relative to a second section of the external tubing. The assembly may also include an earth removal member coupled to the second end of the shoe. The first section of the shoe is disposed between the earth removal member and the second section of the shoe. In another embodiment, the assembly may include a casing string having a first portion with a larger inner diameter than a second portion. The assembly may also include an earth removal member coupled to an end of the casing string. The first portion of the casing string is disposed between the earth removal member and the second portion of the casing string.

Abstract: A tubing shoe (10) for use on work strings in well bores as are typically utilised in oil and gas production. The shoe comprises a cylindrical body (12) upon which is arranged a reaming portion (22) including pairs of teardrop shaped raised reaming members (26), each pair being mounted oppositely, in parallel and longitudinally along the body. Adjacent pairs of members provide a funnel (42) for collecting approaching debris and a channel for grinding the debris. A nose (14) may be mounted on the end of the shoe, the nose being eccentric or including cutting blades to assist the shoe in breaking through shale and clay stone bridges. A non-aggressive stabiliser (54) in the form of helically arranged blades may also be located on shoe.

Abstract: This invention relates to a shoe for wellbore lining tubing and to a method of locating wellbore lining tubing in a wellbore. In one embodiment, a shoe (30) is disclosed which includes a tubular outer body (32) that is coupled to a wellbore lining tubing (28), and a tubular inner body (36) located within the outer body and coupled to fluid supply tubing (38). A generally annular flow area (44) is defined between the bodies which is in selective fluid communication with the well-bore (10), for the return flow of fluid from the wellbore through a flow port (62) in the outer body, along the shoe and into an annulus (46) defined between the wellbore lining tubing and the fluid supply tubing. A valve assembly (40) of the shoe has an actuating member (92) located within the inner body, and a flow controller (96) for selectively closing the flow port. A ball (98) is used to prevent further fluid flow through the inner body into the wellbore.

Abstract: A novel well bore drilling system and method utilizes independently deployable multiple tubular strings to drill, line and cement multiple hole sections without intervening trips to the surface. In one embodiment, the drilling system includes two or more independent, telescoping, tubular members that form a nested tubular assembly and one or more sensors disposed on the nested tubular assembly. The nested tubular string is deployed in the wellbore in conjunction with a Bottom Hole Assembly (BHA). In some embodiments, a drilling motor for rotating a drill bit is also positioned in the tubular assembly. The sensors can be disposed in a stator of the drilling motor or adjacent the motor. Also, in embodiments, the sensors can be positioned on extensible members that can position the sensor or sensors adjacent the wellbore wall.

Abstract: A cement float collar can be positioned downhole and used in a wellbore completion operation after drilling a wellbore with casing. The cement float collar is made for pumping downhole and into engagement with a groove formed in the casing, called the profile nipple. As such, no restriction is needed in the casing for accepting or latching the float collar and the portion of casing including the groove can be installed at the start of the drilling operation. In addition, the profile nipple can be used to engage other drilling tools and, therefore, can already be in placed when the final well depth (TD) is reached.

Abstract: An apparatus for deflecting a tubular string preferably comprising at least one side nozzle near the lower end of a first tubular string. The nozzle permits passage of a fluid therethrough from the first tubular string bore and deflects the first tubular string in a substantially horizontal direction. A second tubular string may be lowered over the deflected first tubular string. The second tubular string and the first tubular string are preferably lowered into the sea floor for maintaining their deflection. A method for deflecting a first tubular string and securing the first tubular string in the deflected state preferably comprises lowering the first tubular string axially so that the lower end of the first tubular string is near the sea floor. Preferably, a fluid, such as seawater, is propelled down through the bore of the first tubular string and through at least one side nozzle near the lower end of the first tubular, wherein the fluid moving through the side nozzle deflects the first tubular string.

Abstract: The present invention is an apparatus and a method for casting a cementitious or stone pile into the ground. The present invention comprises an exterior driving casing and an interior mandrel acting in cooperation to hold and deliver the pile forming material. A retrievable driving driving shoe is also disclose.

Abstract: A guide shoe that utilizes an eccentric nose attached to a cylindrical body that has spiraled, ridged blades extending outward from the body. An orientation system is attached between the body and a hollow shaft. The orientation system is designed to allow free rotation of the body and nose about the shaft during the insertion of the tubing into the hole. It does this by providing clearance between a pawl and notches on the cylindrical body. Indexing of the eccentric nose is provided by a slight retraction of the tubing string in the well hole. Friction between the well hole and ridged blade causes the cylindrical body to rotate about the shaft and lock into an oriented position. The guide shoe is attached to the tubing string by a threaded female connection mating to the matching male connection on the tubing string.

Abstract: A casing shoe for a casing string that includes an annular body. The annular body includes an annular recess that forms an outer portion and an inner portion, the inner portion forming and extending into an inner bore. The annular recess can accept an end of the casing string such that the casing string extends between the inner and outer portions. The annular body includes a homogenous material. The casing shoe is used in a method of guiding a casing string into a wellbore where the casing shoe is attached to an end of the casing string. Attaching the casing string includes inserting the end of the casing string into the annular recess such that the casing string extends between the inner and outer portions. The casing string is then inserted into the wellbore.

Abstract: Device for a tool string (2) for insertion in a well, the tool string (2) being provided with a brake nose (1).

Abstract: The present invention provides a downhole cementing apparatus run into a borehole on a tubular. The apparatus is constructed on the pipe in such a way that pressure surge during run-in is reduced by allowing fluid to enter the pipe and utilize the fluid pathway of the cement. In one aspect of the invention, an inner member is provided that filters fluid as it enters the fluid pathway. In another aspect of the invention, various methods are provided within the cementing apparatus to loosen and displace sediment in the borehole prior to cementing.

Abstract: An apparatus and methods for preventing the accumulation of unwanted materials in an enlarged inner diameter portion of a casing or housing. In one aspect of the invention, a sleeve is disposed in the housing to isolate an annular area defined by the outer surface sleeve and the wall of the enlarged inner diameter portion. The sleeve prevents unwanted materials from being disposed in the annular area. The sleeve can later be expanded into the enlarged inner diameter portion, removed from the wellbore or destroyed. In another aspect of the invention, the sleeve is provided and disposed to cover the enlarged inner diameter portion. By covering the enlarged inner diameter portion, unwanted material is prevented from accumulating at said portion and from interfering with the expansion of the next casing into said portion to form a monobore. The sleeve can be made from materials that are dissolvable, elastically deformable, or retrievable.

Abstract: An apparatus for reverse circulation cementing of surface casing in subterranean formations and associated methods are provided. One example of a method may involve a method of reverse circulation cementing a surface casing in a well bore with a conductor casing positioned therein comprising: providing a tool comprising at least one isolation device coupled to the surface casing; positioning the isolation device in the well bore to isolate an annulus between the surface casing and the conductor casing; flowing cement through a port in the conductor casing in a reverse circulation direction; and allowing the cement to set therein.

Abstract: Embodiments of the present invention generally provide methods and apparatus for forming a tubular-lined wellbore which does not decrease in diameter with increasing depth or length. Methods and apparatus for forming a substantially monobore well while drilling with casing are provided. In one aspect, a portion of a second casing is expanded into a portion of a first casing having a larger inner diameter than the remaining portion of the first casing string. In another aspect, the portion of the second casing is expanded into a portion of the first casing having a compressible member therearound. In another aspect, a lined lateral wellbore may be constructed by forming a lateral wellbore extending from a main wellbore lined with casing. A diameter of at least a portion of the lateral wellbore may be expanded. An expandable tubular element may be run into lateral wellbore and expanded to have an inner diameter equal to or larger than an inner diameter of the main wellbore casing.

Abstract: A liner is inserted in the casing and is preferably expanded into sealing contact with the mounting location on the casing. After expansion a cement retainer positioned at the bottom of the expanded liner and the sliding sleeve located either above the mounting location of the liner in the casing shoe or in the liner below the mounted top section allow cement to be delivered outside the expanded liner and the displaced wellbore fluid to return into the casing through so that the liner can be cemented. The cement retainer can be delivered with either the liner or the expansion tools to allow expansion and cementing in a single trip. A shifting tool can be run on the expansion string to actuate the sliding sleeve and if necessary to allow for cement to be pumped from the drill string into the annulus through the sliding sleeve. The cement retainer can be milled out in a separate trip.

Abstract: A tubing shoe (10) for use on work strings in well bores as are typically utilised in oil and gas production. The shoe comprises a cylindrical body (12) upon which is arranged a reaming portion (22) including pairs of teardrop shaped raised reaming members (26), each pair being mounted oppositely, in parallel and longitudinally along the body. Adjacent pairs of members provide a funnel (42) for collecting approaching debris and a channel for grinding the debris. A nose (14) may be mounted on the end of the shoe, the nose being eccentric or including cutting blades to assist the shoe in breaking through shale and clay stone bridges. A non-aggressive stabiliser (54) in the form of helically arranged blades may also be located on shoe.

Abstract: A cement float collar is made for pumping downhole and into engagement with a groove formed in the casing, called the profile nipple. As such, no restriction is needed in the casing for accepting or latching the float collar and the portion of casing including the groove can be installed at the start of the drilling operation. In addition, the profile nipple can be used to engage other drilling tools and, therefore, can already be in place when the final well depth (TD) is reached.

Abstract: A casing bit, which may comprise a composite structure, for drilling a casing section into a subterranean formation, and which may include a portion configured to be drilled therethrough, is disclosed. Cutting elements and methods of use are disclosed. Adhesive, solder, electrically disbonding material, and braze affixation of a cutting element are disclosed. Differing abrasive material amount, characteristics, and size of cutting elements are disclosed. Telescoping casing sections and bits are disclosed. Aspects and embodiments are disclosed including: at least one gage section extending from the nose portion, at least one rotationally trailing groove formed in at least one of the plurality of blades, a movable blade, a leading face comprising superabrasive material, at least one of a drilling fluid nozzle and a sleeve, grooves for preferential failure, at least one rolling cone affixed to the nose portion, at least one sensor, discrete cutting element retention structures, and percussion inserts.

Abstract: A casing shoe for a casing string that includes an annular body. The annular body includes an annular recess that forms an outer portion and an inner portion, the inner portion forming and extending into an inner bore. The annular recess can accept an end of the casing string such that the casing string extends between the inner and outer portions. The annular body includes a homogenous material. The casing shoe is used in a method of guiding a casing string into a wellbore where the casing shoe is attached to an end of the casing string. Attaching the casing string includes inserting the end of the casing string into the annular recess such that the casing string extends between the inner and outer portions. The casing string is then inserted into the wellbore.

Abstract: A method and apparatus for cementing an annulus wellbore is described herein. The apparatus includes an internally radiused portion of a sleeve adapted for increasing the compressive strength of a compound for securing a valve in the sleeve. The internally radiused portion prevents the apparatus from leaking during operation. The apparatus is manufactured using one pass of a milling tool. The apparatus is run into a wellbore. A cementing operation in performed past the apparatus. The apparatus then prevents the cement from entering a downhole tubular.

Abstract: An anchoring device for tool is disclosed that can be positioned downhole and used in casing. The anchoring device can have an architecture that supports installation by running downhole and into engagement with a recess formed in the casing. The anchoring device can support the use of weak materials such as plastic.

Abstract: The present invention provides a downhole cementing apparatus run into a borehole on a tubular. The apparatus is constructed on the pipe in such a way that pressure surge during run-in is reduced by allowing fluid to enter the pipe and utilize the fluid pathway of the cement. In one aspect of the invention, an inner member is provided that filters fluid as it enters the fluid pathway. In another aspect of the invention, various methods are provided within the cementing apparatus to loosen and displace sediment in the borehole prior to cementing.

Abstract: An apparatus to protect the mounting area of casing when subsequently attaching a tubular is disclosed. A sleeve that defines a sealed cavity having a loose incompressible material inside covers the mounting location on the casing. The cementing of the casing takes place through the sleeve. After the cementing, the sleeve is drilled out and the incompressible material is removed to the surface with the drill cuttings. A tubular is inserted in the casing and is preferably expanded into sealing contact with the mounting location on the casing. At the end of expansion, the run in shoe on the tubular is retrieved.

Abstract: A float system for use in cementing a casing in a wellbore. The wellbore is drilled with a drill bit attached to the casing. The drill bit is removed after the wellbore is drilled. The float system is lowered into the casing after the drill bit is removed. The float system includes a packer apparatus with a float apparatus, preferably a float shoe, attached to the end thereof. The packer apparatus is set in the casing to hold the float shoe in position. A bottom cementing plug is placed in the casing and is urged downwardly until it engages the upper end of the packer apparatus. The cement will flow through the packer apparatus and the float apparatus to fill the annulus between the casing and the wellbore.

Abstract: An apparatus and methods for preventing the accumulation of unwanted materials in an enlarged inner diameter portion of a casing or housing. In one aspect of the invention, a sleeve is disposed in the housing to isolate an annular area defined by the outer surface sleeve and the wall of the enlarged inner diameter portion. The sleeve prevents unwanted materials from being disposed in the annular area. The sleeve can later be expanded into the enlarged inner diameter portion, removed from the wellbore or destroyed. In another aspect of the invention, the sleeve is provided and disposed to cover the enlarged inner diameter portion. By covering the enlarged inner diameter portion, unwanted material is prevented from accumulating at said portion and from interfering with the expansion of the next casing into said portion to form a monobore. The sleeve can be made from materials that are dissolvable, elastically deformable, or retrievable.

Abstract: A drill bit for drilling casing in a well bore. The drill bit is constructed from a combination of relatively soft and relatively hard materials. The proportions of the materials are selected such that the drill bit provides suitable cutting and boring of the well bore while being able to be drilled through by a subsequent drill bit. Methods of applying hard materials to a soft material body are provided.

Abstract: An expandable reamer shoe is provided for use with expandable casing in a borehole. The reamer shoe has a number of reaming members in the form of blades which remain closed against the body of the shoe when inserted through casing, and can then be expanded to underream below the casing. Additionally, the expandable reamer shoe is made substantially of a drillable material so that the borehole can be extended beyond the point reached by the expandable reamer shoe.

Abstract: An apparatus for preventing or limiting the rotation of cementing plugs in a casing string during drillout. The apparatus includes an outer housing with a sleeve disposed therein. The sleeve has an inner surface configured to engage cementing plugs received therein to cause an interference fit. The sleeve will hold the cementing plugs when rotational forces, such as drilling forces, are applied so that during drillout, rotation of the cementing plug is prevented or is at least limited.