Abstract: Tools and methods for cutting multiple, co-extending casings in oil and gas wells are provided. The tools comprise a cylindrical body and first and second sets of cutting blades. Each set of cutting blades is mounted to the body for actuation from a retracted, run-in position to an extended, cutting position. The cylindrical body is rotated and the first set of cutting blades is actuated to cut the co-extending casings within a first sweep diameter. The second set of cutting blades then is actuated to cut the co-extending casings beyond the first sweep diameter and within a second sweep diameter.

Abstract: A section mill for removing a portion of a casing in a wellbore. The section mill may include a body having a first end portion, a second end portion, and a bore formed axially therethrough. A plurality of blades may be coupled to the body. Each of the blades may have a first end portion and a second end portion. The first end portion of each blade may be coupled to the body via a hinge pin, and the second end portion of each blade may have a cutting surface formed thereon. A seat may be formed within the bore. The blades may be adapted to actuate from an inactive position to an active position in response to an impediment forming a seal against the seat.

Abstract: A section mill features extendable cutting blades and centering blades that are pressure actuated for sequential extension of the centering blades before the cutting blades. Applied pressure results in flow through a flow restriction that creates a force on return springs associated with the centering and the cutting blades. The springs allow extension of the centering blades before the cutting blades. Another spring returns a mandrel to the run in position on cessation of flow. The blades are extended or retracted with a rack and pinion drive system.

Abstract: Multiple section mills are run in a single trip with an intervening mill preferably a watermelon mill to grind up any cuttings that get past the first mill in a direction toward the second mill below it. The blades of the second mill are held by the innermost tubular until the location of the initial cut is reached at which point the longer arms of the second mill can be extended and its body centralizes due to the flexibility of the connection between the mills.

Abstract: Methods and apparatus, for performing rotary, cutting and/or crushing operations in a subterranean borehole or conduit thereof, which use higher and lower pressures therein to operate a motor, actuator and/or piston, particularly for sealing operations using a downhole assembly, placeable with a cable. The downhole assembly comprises at least a motor or actuator coupled to at least one of a rotary tool, axial cutting tool and/or packer or piston. The motor or actuator piston may be operated by differential fluid pressure across ends thereof, to form a space free of debris that may be provided for placement of a settable sealing material to prevent leakage paths in the concrete seal of said subterranean borehole or conduits thereof.

Abstract: In order to reduce the risk of accidents in mechanically drilling through a stratum and to expand the range of applications of the device for drilling through a stratum, the invention provides that the control elements which ensure the in-feeding of the cutting rod and the return of the device to the position for being transported by means of interacting the ball-and-socket joint with the control bushing and the body—are embodied as two-stage figure projections on the lateral truncations of the ball-and-socket joint, which cooperate with cutouts in the control bushing and the body; and the line of pipes and the hydraulic motor of the suspension and of the pivot point are optionally replaced by a cable and by an electric motor combined with a hydraulic pump.

Abstract: A milling tool for enlarging portions of a wellbore. The milling tool includes a housing that defines a central bore along its length. A piston is moveably disposed within the central bore, and axial movement of the piston moves support arms radially outwardly from the housing. The support arms carry milling blades for enlarging portions of a wellbore.

Abstract: A dual string section milling tool includes a cutting block deployed in an axial recess in a tool body. The cutting block is configured to extend radially outward from and retract radially inward towards the tool body. The cutting block is further configured to remove a cement layer in a wellbore. The dual string section milling tool further includes a milling blade deployed in an axially slot disposed in the cutting block. The milling blade is configured to extend radially outward from and inwards towards the cutting block. The milling blade is further configured to cut and mill a section of casing string. The dual string section milling tool may be further configured to simultaneously remove cement and mill a wellbore tubular.

Abstract: A method and device for closing a well with a casing in a formation in the ground are provided. The method has the steps of moving a cutting tool down into the well; removing a longitudinal portion of the casing by cutting the longitudinal portion into pipe wall pieces; removing the cutting tool; and setting a plug against the formation in the longitudinal portion from which the casing has been removed.

Abstract: A particle impact drilling system and method are described. In several exemplary embodiments, the system and method may be a part of, and/or used with, an apparatus or system, methods, to excavate a subterranean formation. The system can including, for example, removing near-borehole damage, casing, window milling, fishing, drilling with casing, under reaming, coring, perforating, effective circulatory density management, assisted annular flow, and directional control. Embodiments of associated systems and methods are also included.

Abstract: A method for forming and sealing a hole in a sidewall of a borehole may include conveying a bit and a sealer into the borehole using a carrier, forming a hole in the sidewall using the bit, and introducing a sealant from the sealer to the hole along a surface portion of the bit. An apparatus for forming and sealing a hole in a sidewall of a borehole includes a carrier conveyable into the borehole, a bit disposed on the carrier that forms the hole in a sidewall, and a sealer operable to introduce a sealant to the hole along a surface portion of the bit.

Abstract: A communication tool apparatus is described which is adapted to provide selective communication of control fluid through a downhole tool, such as a safety valve. The downhole safety valve is a tubing retrievable subsurface safety valve (“TRSSSV”). The communication tool may be run downhole and within the TRSSSV. Once within the TRSSSV, the communication tool apparatus activates a cutting device within the TRSSSV such that communication of control fluid through the TRSSSV is possible. A replacement safety valve run on a wireline may then be inserted into the TRSSSV and be operated via the control fluid line, as a new communication path created by the communication tool described herein. A method of using the communication tool apparatus is also described.

Abstract: Casing cutter for severing multiple tubulars in a well bore has a pair of cutter blades pivotally mounted on a support body. The blades are pivotally mounted for gradual movement outside of the support body when downward force is applied to proximate ends of the cutter blades. The support body is rotated inside the innermost of the multiple tubulars, while the cutter blades sever the tubulars of progressively increasing diameter. Should the cutter blades or pivotal connections become unusable, the tool body can be rotated about the vertical axis and secured to a downhole string by the opposite end. A substitute pair of cutter blades are then engaged on the tool body and operated to cut the casings similar to the first set of the cutter blades.

Abstract: Embodiments of the present invention generally relate to a method and/or apparatus for deploying wireline tools with a non-electric string. In one embodiment, a method of determining a free point of a tubular string stuck in a wellbore includes deploying a tool string in the stuck tubular with a non-electric string. The free point assembly includes a battery, a controller, and a free point tool. The method further includes activating the free point tool by the controller. The free point tool contacts an inner surface of the stuck tubular string. The method further includes applying a tensile force and/or torque to the stuck tubular string; and measuring a response of the tubular string with the free point tool.

Abstract: Apparatus for performing rotary or cutting operations in a subterranean borehole or conduit, particularly sealing operations, comprises a downhole assembly connected to a cable. The downhole assembly comprising at least one of a rotary tool coupled to an electric motor or fluid motor, a rotary tool coupled to a fluid motor, or an axial cutting tool coupled to a piston. The fluid motor or piston is operated by differential fluid pressure created within the bore. Methods of sealing a subterranean borehole are also provided, in which one or more cuts are made with a cutting assembly in one or more conduits to remove at least a portion of a conduit and concrete is deposited in the resulting space. The space is free of debris, which could otherwise form leakage paths in the concrete seal. In a variant the space is created with a downhole crushing apparatus.

Abstract: A method for adapting a tubular element extending into a wellbore formed in an earth formation, where the tubular element is susceptible to damage caused by axially compressive forces acting on the tubular element as a result of compaction of the earth formation surrounding the tubular element. The method comprises the steps of reducing the axial stiffness of at least one section of the tubular element, and allowing each tubular element section of reduced axial stiffness to be axially compressed by the action of said axially compressive forces, thereby accommodating compaction of the earth formation surrounding the tubular element.

Abstract: A bottom hole assembly in a casing-while-drilling operation is retrieved attaching a wireline to the bottom hole assembly. The density of the fluid in the casing string is lightened to a lesser density than the fluid in the annulus, thereby creating a pressure differential between fluid above the bottom hole assembly and fluid below the bottom hole assembly to exert an upward force on the bottom hole assembly. The operator pulls upward on the wireline to assist the upward force in moving the bottom hole assembly up the casing string.

Abstract: An apparatus for perforating wells having a plurality of perforating charges; means for retaining the perforating charges in a first array, the first array having a first maximum cross sectional area; and means for expanding the perforating charges into a second three dimensional array, the second array having a second maximum cross sectional area larger than the first maximum cross sectional area. Also an apparatus for perforating wells having a plurality of perforating charges; means for retaining the perforating charges in a first array, the first array having a primary axis and a first maximum cross sectional area and the perforating charges having firing directions oriented approximately perpendicular to the primary axis; and means for expanding the perforating charges into a second array, the second array having a second maximum cross sectional area larger than the first maximum cross sectional area.

Abstract: Disclosed herein is a downhole cutting tool. The downhole cutting tool including, a cutting member mounted on a rotatable shaft, a shaft-deflecting device in operable communication with the shaft, and a motor in operable communication with the shaft.

Abstract: A methodology and apparatus for cutting shape(s) or profile(s) through well tubular(s), or for completely circumferentially severing a well through multiple tubulars, including all tubing, pipe, casing, liners, cement, other material encountered in tubular annuli. This rigless apparatus utilizes a computer-controlled, downhole robotic three-axis rotary mill to effectively generate a shape(s) or profile(s) through, or to completely sever in a 360 degree horizontal plane wells with multiple, nested strings of tubulars. This is useful for well abandonment and decommissioning where complete severance is necessitated and explosives are prohibited, or in situations requiring a precise window or other shape to be cut through a single tubular or plurality of tubulars.

Abstract: Downhole fluid jet cutting tools having extendible and retractable arms with cutting heads on the ends are disclosed. The jet cutting tools permit casing and other downhole surfaces to be cut utilizing a cutting fluid forced through a jet nozzle assembly. Inflation of an inflatable member within the passageway of the tool moves the jet nozzle assembly when cutting fluid pressure inflates the inflatable member. As a result, a cutting head of the jet nozzle assembly is extended and cutting fluid is forced at high pressure from the passageway to the cutting head where it is expelled through nozzles for cutting casing and the like. The jet cutting tools permit the cutting head to be extended, retracted, and re-extended or redeployed multiple times without the need for being retrieved from the wellbore.

Abstract: Downhole fluid jet cutting tools having extendible and retractable arms with cutting heads on the ends are disclosed. The jet cutting tools permit casing and other downhole surfaces to be cut utilizing a cutting fluid forced through a jet nozzle assembly. Movement of a piston slidingly engaged within the passageway of the tool actuates the arms when cutting fluid pressure acts on the piston. As a result, the arms are extended and cutting fluid is forced at high pressure from the passageway to the cutting head where it is expelled through nozzles for cutting casing and the like. The jet cutting tools permit the arms to be extended, retracted, and re-extended or redeployed multiple times without the need for being retrieved from the wellbore.

Abstract: Disclosed herein relates to a single piece tubular member. The tubular member having a non-radially displaceable portion and a radially displaceable portion, the radially displaceable portion being movable to a position of similar radial displacement as that of the non-radially displaceable portion and a position of relatively large radial displacement in comparison to the non-radially displaceable portion. The tubular member also having at least one cutting arrangement disposed at the radially displaceable portion.

Abstract: An apparatus for radially expanding and plastically deforming a tubular member.

Abstract: An apparatus and method of determining the point at which a tubular is stuck within another tubular or a wellbore by applying a tensile or torsional force to the stuck tubular and measuring the response of various locations within the tubular. In addition, the apparatus may be combined with a cutting tool to separate the free portion of the tubular from the stuck portion.

Abstract: The casing cutter disclosed herein is useful for severing downhole tubulars and comprises a body, slips, a cutting head, cutting blades, and actuators for operating the cutting head and cutting blades. The casing cutter can be anchored within casing wellbore with the slips to provide anchoring support during the cutting operation. Cutting is accomplished by rotatingly actuating the cutting head with an associated motor, and then radially extending the cutting blades away from the cutting head. The cutting blades are actuated by a hydraulic motor operatively coupled to the cutting blades by a series of gears.

Abstract: The present invention generally relates to a cutting insert for use with wellbore milling tools. The cutting insert forms an angle between a milling surface of the insert and a surface of the tool that the insert is attached to in order to provide the proper cutting incline, and substantially perpendicular sides of the insert relative to the milling surface of the insert provide continuous support for the milling surface. In addition, the inserts can comprise spacers and legs that evenly distribute bonds formed between inserts and bonds formed between the inserts and the surface of the tool, respectively. Selecting the dimensions of the spacers and legs alters the strength of the bonds.

Abstract: A technique for deploying expandables is provided. The technique comprises actuating an expansion tool such that the expansion tool imparts an outwardly directed radial force on an expandable tubular. More specifically, the expansion tool imparts radial expansion forces against an interior surface of the tubular thereby allowing the tubular to be deployed in a wellbore environment.

Abstract: The present invention provides methods and apparatus for cutting tubulars in a wellbore. In one aspect of the invention, a cutting tool having radially disposed rolling element cutters is provided for insertion into a wellbore to a predetermined depth where a tubular therearound will be cut into an upper and lower portion. The cutting tool is constructed and arranged to be rotated while the actuated cutters exert a force on the inside wall of the tubular, thereby severing the tubular therearound. In one aspect, the apparatus is run into the well on wireline which is capable of bearing the weight of the apparatus while supplying a source of electrical power to at least one downhole motor which operates at least one hydraulic pump. The hydraulic pump operates a slip assembly to fix the downhole apparatus within the wellbore prior to operation of the cutting tool. Thereafter, the pump operates a downhole motor to rotate the cutting tool while the cutters are actuated.

Abstract: A section mill for casings used in oil wells to cut predetermined portions for repair purposes. An elongated cylindrical assembly is inserted through the casing and it includes at least two spaced apart apertures with one blade member pivotally mounted within each aperture. First and second coaxially disposed tubular shaft assemblies with teethed portions to coact with the blades to selectively move them between two extreme position upon the application of a pressurized fluid. The fluid needs to overcome the spring biased applied to the shaft assemblies. The first set of blades is stopped and slidably rotates in contact with the internal surface of the casing. The second set cuts through the casing with one end and sections the casing with the other end. After wearing off, the first set of blades continues the sectioning work.

Abstract: The present invention provides methods and apparatus for cutting tubulars in a wellbore. In one aspect of the invention, a cutting tool having radially disposed rolling element cutters is provided for insertion into a wellbore to a predetermined depth where a tubular therearound will be cut into an upper and lower portion. The cutting tool is constructed and arranged to be rotated while the actuated cutters exert a force on the inside wall of the tubular, thereby severing the tubular therearound. In one aspect, the apparatus is run into the well on wireline which is capable of bearing the weight of the apparatus while supplying a source of electrical power to at least one downhole motor which operates at least one hydraulic pump. The hydraulic pump operates a slip assembly to fix the downhole apparatus within the wellbore prior to operation of the cutting tool. Thereafter, the pump operates a downhole motor to rotate the cutting tool while the cutters are actuated.

Abstract: A combination tool for attaching to a stuck wireline tool, then cutting the wireline just above the stuck tool with a hydraulically driven cutter, allowing the wireline to be pulled out of the hole before fishing out the stuck tool. A side door can be provided on the work string, to allow rerouting of the wireline outside the work string, after which the stuck tool can be unstuck and repositioned within the well bore for completion of the downhole operation of the tool, prior to cutting the wireline free from the downhole tool.

Abstract: A combination tool for attaching to a stuck wireline tool, then cutting the wireline just above the stuck tool with a hydraulically driven cutter, allowing the wireline to be pulled out of the hole before fishing out the stuck tool. A side door can be provided on the work string, to allow rerouting of the wireline outside the work string, after which the stuck tool can be unstuck and repositioned within the well bore for completion of the downhole operation of the tool, prior to cutting the wireline free from the downhole tool.

Abstract: The present invention generally relates to downhole tools. More particularly, the invention relates to a locking mechanism for use on a downhole tool. A flow actuated locking mechanism is provided for a downhole tool that includes an annular, two-position sleeve having an unlocked position and a locked position. A pin assembly within the tool is used to retain the sleeve in the locked position. In one aspect of the invention, the locking mechanism is used on a reaming tool with extendable cutters that are extendable from the body of the tool to increase the diameter of the tool and aid in forming a wellbore therearound. The locking mechanism prevents the cutters from collapsing or closing as the reamer is moved axially in the wellbore.

Abstract: A downhole chemical cutter (12) has first and second passages (124, 126) which extend parallel, in fluid communication with an interior passage (32). A first ignitor (210) in the first passage (124) ignites a propellant (34) in the interior passage (32) to dispense a cutting chemical (46). The second passage (126) extends from the interior passage (32) to an exterior of the chemical cutter (12), and is sealed by members (176, 156). After the first ignitor (210) is fired, the second ignitor (218) is fired to push the members (176, 156) from sealing the second ignitor passage (126), such that the interior passage (32) is in fluid communication with the exterior of the chemical cutter (12). A control circuit (252) has two diodes (106, 110) connected in parallel and configured for passing current of opposite polarity to respective ones of the first and second ignitors (210, 218).

Abstract: Methods and apparatus for shaping pipes, tubes, liners, or casing at downhole locations in wells. Use is made of rollers bearing radially outwards against the inside wall of the pipe (etc.), the rollers being rolled around the pipe to cause outward plastic deformation which expands and shapes the pipe to a desired profile. Where one pipe is inside another, the two pipes can be joined without separate components (except optional seals). Landing nipples and liner hangers can be formed in situ. valves can be deployed to a selected downhole location and there sealed to the casing or liner without separate packers. Casing can be deployed downhole in reduced-diameter lengths and then expanded to case a well without requiring larger diameter bores and casing further uphole. The invention enables simplified downhole working, and enables a well to be drilled & produced with the minimum downhole bore throughout its depth, obviating the need for large bores.

Abstract: An improved expansion assembly for an expander tool is provided. The expander tool is used to expand a surrounding tubular body within a wellbore. The expansion assembly first comprises a piston disposed within a recess of the expander tool. The top surface of the piston defines a bearing cavity configured to closely receive a roller. A shoe is further disposed on the top surface of the piston to receive a lower portion of the roller. In one arrangement, the roller is a tapered cylindrical roller actuated by hydraulic pressure applied from within the bore of the expander tool. Actuation of the tool forces the pistons to radially extend away from the body of the tool within the recesses. This, in turn, causes the roller members to engage the inner surface of the surrounding tubular body to be expanded. Rotation of the expander tool causes the rollers to at least partially rotate within the bearing cavity.

Abstract: A method of expanding tubing comprises the steps: providing a length of expandable tubing; locating an expansion tool, such as a cone, in the tubing; and applying impulses to the tool to drive the tool through the tubing and expand the tubing to a larger diameter. The tubing may be located downhole and may have a solid wall or a slotted wall.

Abstract: A method and apparatus for advancing a rotating motorized downhole tool for operations in oil/gas wells. The apparatus is adapted for drilling and milling away of casing sections in the wells, as preparation for plugging the same. The apparatus includes a rotating tool and a driving motor indirectly suspended on coiled tubing. The apparatus also includes a carriage connected to the motor adapted to absorb torques that occur during use. The carriage is connected to the coiled tubing via a swivel coupling such that a tensile force on the coiled tubing provides an advancing force for the tool and motor.

Abstract: A method and apparatus for milling a section of casing in an upward direction, utilizing a downhole hydraulic thrusting mechanism for pulling a section mill upwardly. A downhole motor and torque anchor can be used to rotate the section mill, or the mill can be rotated by a work string. A stabilizer above the section mill can be used to stabilize the mill relative to the casing being milled. A spiral auger below the section mill can be used to move the cuttings downwardly.

Abstract: The present invention provides methods for expanding coiled tubing within a wellbore in order to form a patch. In one aspect, an expansion assembly is run into the wellbore at the lower end of a string of coiled tubing. The expansion assembly includes a cutting tool and an expander tool. The coiled tubing is run into the wellbore such that the expander tool is adjacent a portion of surrounding casing or other tubular body to be patched. The expander tool is actuated so as to expand a selected portion of the coiled tubing into frictional engagement with the surrounding casing, thereby forming a patch within the wellbore. The cutting tool is actuated so as to sever the coiled tubing downhole above the patch. The severed coiled tubing is then pulled, thereby removing the expansion assembly from the wellbore as well.

Abstract: A perforator apparatus for repeated punching of holes at a multiple of selected locations in tubing of a well bore. The apparatus is activated for repeated punching operations by a fluid control valve mechanism that controls opposed directional movement of a piston connected to a punch of the perforator apparatus.

Abstract: An apparatus and method for expanding a lower string of casing into frictional contact with an upper string of casing, and thereby hanging the lower string of casing onto the upper string of casing is provided. The apparatus essentially defines a lower string of casing having a separation region formed in the top end thereof. The lower string of casing is run into the wellbore, and positioned so that the top end overlaps with the bottom end of an upper string of casing already cemented into the wellbore. The top end of the lower casing string is expanded below the depth of the separation region into frictional contact with the upper string of casing. At the same time, or shortly thereafter, the top end of the upper string of casing is expanded. As the portion of the lower casing string having the separation region is expanded, the casing severs into upper and lower portions.

Abstract: A downhole tool (10) for mounting on a drill string comprises: a mandrel (16); a body (18) axially movably mounted on the mandrel; and radially extendable members, such as stabiliser blades or cutters (30), mounted in the body and being operatively associated with the mandrel such that relative axial movement of the mandrel and body induces radial movement of the members. Application of axial tension to the tool produces axial movement of the body relative to the mandrel, tending to retract the members from an extended configuration. The mandrel may be arranged to draw the members inwardly to permit positive retraction of the members from an extended configuration. Further, the body may define a channel (32) and the mandrel and the members include an arrangement (38, 39, 40, 42) for maintaining a desired orientation of the members relative to the body channel.

Abstract: The present invention provides methods and apparatus for cutting tubulars in a wellbore. In one aspect of the invention, a cutting tool having radially disposed rolling element cutters is provided for insertion into a wellbore to a predetermined depth where a tubular therearound will be cut into an upper and lower portion. The cutting tool is constructed and arranged to be rotated while the actuated cutters exert a force on the inside wall of the tubular, thereby severing the tubular therearound. In one aspect, the apparatus is run into the well on wireline which is capable of bearing the weight of the apparatus while supplying a source of electrical power to at least one downhole motor which operates at least one hydraulic pump. The hydraulic pump operates a slip assembly to fix the downhole apparatus within the wellbore prior to operation of the cutting tool. Thereafter, the pump operates a downhole motor to rotate the cutting tool while the cutters are actuated.

Abstract: The present invention provides an active downhole cutting tool guide device 14 for use in a hole 17 with sides between which a hole-cutting tool 15 mounted on a drill string and provided with said device may be disposed. The guide device 14 comprises at least one elongate longitudinally extending hole-side engagement member 20 mounted on a body 19 disposable, in use of the device, in-line with the drill string, so as to be movable relative to said body 19 between a retracted position and a radially outwardly displaced position for hole-side engagement. Each engagement member 20 has pressurized-fluid operable actuator mechanism 24 formed and arranged for driving said hole-side engagement member 20 between its retracted and hole-side engagement positions. The guide device 14 includes pressurized fluid supply mechanism 28, 18 formed and arranged for controlling the supply of pressurized fluid to the actuator mechanism 24, for operation thereof.

Abstract: The present invention relates to methods and apparatus for expanding tubulars in a wellbore. In one aspect of the invention, an expansion tool with hydraulically actuated, radially expandable members is disposed on a string of coil tubing. In another aspect of the invention the apparatus is utilized to expand a tubular lining a lateral wellbore into contact with a window of a larger tubular lining a central wellbore.

Abstract: The invention relates to a method for the formation of a plug (1) in a petroleum well (2) extending from the earth's surface or the sea floor to a petroleum reservoir, which well is lined with casing (3, 3′). At least one opening (4) is formed in the casing (3) at a distance from the earth's surface, and a liquid curable resin is provided in at least a portion of the opening (4) and an adjacent area of the well (2), whereby the resin after curing forms a plug (1) in the well. The invention also relates to a tool (9) for milling an opening (4) in a casing (3) of a petroleum well (2), and a plug (1) for plugging casing (3) of a petroleum well (2).

Abstract: Methods and apparatus for shaping pipes, tubes, liners, or casing at downhole locations in wells. Use is made of rollers bearing radially outwards against the inside wall of the pipe (etc.), the rollers being rolled around the pipe to cause outward plastic deformation which expands and shapes the pipe to a desired profile. Where one pipe is inside another, the two pipes can be joined without separate components (except optional seals). Landing nipples and liner hangers can be formed in situ. Valves can be deployed to a selected downhole location and there sealed to the casing or liner without separate packers. Casing can be deployed downhole in reduced-diameter lengths and then expanded to case a well without requiring larger diameter bores and causing further uphole. The invention enables simplified downhole working, and enables a well to be drilled & produced with the minimum downhole bore throughout its depth, obviating the need for large bores.

Abstract: A method of machining a workpiece in a subterranean wellbore comprises the steps of: (a) providing a workpiece that comprises (1) a first section that comprises a first material, and (2) a second section that comprises a second material, the second section forming at least one surface of the workpiece; (b) placing the workpiece in a subterranean wellbore that is surrounded by a geologic formation; and (c) machining the workpiece to remove at least part of the second material in the second section, whereby at least one surface of the workpiece is formed into a desired configuration. This method allows, for example, a landing nipple to be installed in a wellbore, and customized locking recesses to be formed in the inner surface of the nipple at a later time.