Abstract: A drill string tool such as a drill string stabilizer (1) comprises a circumferentially continuous bearing sleeve (6) having an outside diameter which is equal to or greater than the outside diameter of a radially outermost part of the drill string tool.

Abstract: A system for lining a section of a wellbore with an expandable tubular element is provided. The system includes an elongate string extending into the wellbore, the string being provided with the tubular element in the unexpanded form thereof whereby the tubular element surrounds a lower portion of the string. The string is further provided with an expander arranged at a lower end part of the tubular element and anchoring means for anchoring an upper end part of the tubular element in the wellbore.

Abstract: A stabiliser is disclosed for stabilising a radially expandable tubular element extending in a wellbore drilled into an earth formation. The stabiliser comprises a radially expandable tubular member selected from a section of the tubular element and a sleeve surrounding the tubular element, and at least one stabiliser arm connected to the tubular member, each arm being movable from a radially retracted position to a radially extended position by the action of a spring force. The stabiliser further comprises locking means arranged to lock each arm in the retracted position when the tubular element is in the unexpanded form and to unlock the arm upon radial expansion of the tubular member so as to allow the arm to move to the extended position thereof.

Abstract: A centralizer is disclosed for stabilizing a radially expandable tubular element extending in a wellbore drilled into an earth formation. The centralizer has a tubular member selected from a section of the tubular element and a sleeve surrounding the tubular element, and at least one centralizer blade, each blade including a first arm connected to the tubular member in a manner allowing the first arm to hinge relative the tubular member between a radially retracted position and a radially extended position thereof, and a second arm connected to the tubular member at a point circumferentially spaced from the point of connection of the first arm to the tubular member. The second arm has an end part connected to the first arm so as to induce movement of the first arm from the retracted position to the extended position upon radial expansion of the tubular member.

Abstract: A stabiliser (10) has a body (12) having a through-bore (16). A mandrel (14), also having a through-bore (20), is axially slidable in the body bore to actuate and de-actuate the tool. A step (64) in the body defines annular chambers (102, 104) between the mandrel and body on either side of the step. A control piston (18) in the mandrel alternately directs drilling mud pumped under pressure along said body bore and mandrel bore to the chambers to drive the mandrel hydraulically to actuate and de-actuate the tool. The control piston has a through-bore (46) and is slidable in the mandrel bore against the force of a return spring (40) by drilling mud pressure from a low-pressure position to a pressure position. The pressure position is alternately one of an actuate position (a) and a de-actuate position (b), axially spaced along the mandrel bore from said actuate position.

Abstract: A crimpable wear band (105) tool has been invented for installation on casing (6), used in well bore drilling. A wear band (105) is provided having a cylindrical body which when coaxially placed over a pipe and substantially radially inwardly displaced at a plurality of points (i.e. crimped) about the circumference of a section of cylindrical body, attaches to the pipe to create a connection having structurally significant axial and torque load transfer capacity. When crimped according to the methods of the present invention, the load transfer capacity of the connection between the wear band (105) tool and the pipe (6) can be arranged to substantially prevent significant relative movement of the wear band tool on the pipe under loads that may be encountered when using one or more of the pipes as components of a tubular string used for drilling or running the casing in to complete a well bore.

Abstract: A crimpable centralizer has been invented for installation on pipe, such as would be useful in well bore drilling and casing operations. The present invention provides a centralizer having a cylindrical body which when coaxially placed over a pipe and substantially radially inwardly displaced at a plurality of points (i.e. crimped) about the circumference of a section of the cylindrical body, attaches to the pipe to create a connection having structurally significant axial and torque load transfer capacity. When crimped according to the methods of the present invention, the load transfer capacity of the connection between the centralizer and the pipe can be arranged to substantially prevent significant relative movement of the centralizer on the pipe under loads that may be encountered when using one or more of the pipes as components of a tubular string used for drilling or completing well bores.

Abstract: A drill pipe protector having a tubular sleeve that is attached to a section of drill pipe and resides over the outer diameter of the drill pipe while moving within an associated well casing or well hole. The sleeve has low-friction end pads positioned on the ends of the sleeve to reduce friction between the ends of the sleeve and the end of an adjacent thrust bearing collar used to hold the sleeve in place on the drill pipe.

Abstract: An adjustable down-hole tool, for example a drill-string stabiliser (10), comprises a body (12) having a through bore (16). A mandrel (18) is rotationally fixed but axially movable in the body, the mandrel being movable by fluid pressure in the tool against the action of a first return spring (44) between a first, activated position and a second deactivated position. A sleeve (66) is between shoulders (68, 69) on the body and mandrel. Castellations (18a,b, 69a,b) are on the mandrel and facing edge or edges of the sleeve so that, when the castellations are in phase the mandrel is prevented from travelling from said first to second position and when they are out of phase they interdigitate and the mandrel is not prevented from travelling from said first to second position. A control piston (36) is slidable in the mandrel, being movable by fluid pressure in the tool against the action of a second return spring (50).

Abstract: A spring centralizer device for supporting a tubular member spaced from the wall of a bore is made from a single piece of boron steel material. The spring centralizer device has first and second collars spaced apart along a longitudinal axis. Spring bow portions extend between the collars. As the device is made from a single piece of material, the material extends seamlessly from each collar portion through the bow portions so that there are no joins or points of weakness. Use of boron steel means that the device can be made by cold forming.

Abstract: A hermetic seal functions as a closure between opposite ends of the coupling by combining a metal sleeve and an elastomer sleeve extension. The metal sleeve is sealingly attached to the outer surface of one end of the coupling and the elastomer sleeve, sealingly attached to the metal sleeve, is attached at the distal end to the other end of the coupling. As an alternative, the distal end may be bonded to a second metal sleeve sealingly attached to the other end of the coupling. The seal may be convoluted, with multiple convolutions.

Abstract: The invention is a method and apparatus for determining an electrical property a formation surrounding a borehole with a measuring-while-drilling device. The apparatus an antenna configuration disposed along the outer face of an extendable stabilizer joined to a rotatable drill collar. Typically, two receivers and two transmitters are spaced along the longitudinal axis of the drill collar, with the two receivers spaced symmetrically in between the two transmitters. Alternatively, receivers and transmitters can be spaced along the circumference, possibly over multiple stabilizers. Multiple assemblies can be used. Data can be obtained with the transmitter-receiver assembly held in a stationary position or rotating circumferentially. Apparatus can be operated in a “broadside” configuration, an “endfire” configuration, or a configuration in which transmitter coils and receiver coils are oriented orthogonally to each other.

Abstract: A tool is presented for making density measurements of a formation surrounding a wellbore, comprising a collar housing in a drill string. The housing has at least one first section with a first outer diameter, and at least one sensing section with a second outer diameter located proximate the at least one first section. The second outer diameter is smaller than the first outer diameter. A radioactive source is disposed in the sensing section of the housing. At least two detectors are disposed in the sensing section and spaced from the radioactive source and are positioned to detect radiation resulting from gamma rays emitted by the source.

Abstract: A drill bit is assembled to the makeup end of a drill string by means of a breakable washer comprising a ring-shaped body having an inner diameter and an outer diameter. A radially extending first surface of the ring-shaped body is planar and substantially perpendicular to a centerline axis through the body. A second radially extending surface has an angle with reference to the first surface that results in a radially diverging configuration.

Abstract: A centralizer for use in centralizing casing or other tubulars such as tubulars in an oil or gas well comprising an annular body with a bore extending through the body and one or more blades, the centralizer being adapted to fit around a tubular to be centralized, and comprising a tempered metal such as austemperized ductile iron (ADI).

Abstract: The drill string element has at least one bearing zone for bearing against the wall of the borehole during drilling. The bearing zone comprises at least one bearing segment extending in the axial direction and having an outside surface that is cylindrical and of constant diameter greater than the diameter of any other portion of the surface of the element, and also having a guide zone that is circularly symmetrical about the axis of the drill string element. The bearing zone preferably also has a drilling fluid activation zone extending axially in a disposition adjacent to the bearing segment. The guide zone presents a radius of curvature not less than one-third the outside diameter of the bearing segment.

Abstract: A drill pipe protector having a tubular sleeve that is attached to a section of drill pipe and resides over the outer diameter of the drill pipe while moving within an associated well casing or well hole. The sleeve has low-friction end pads positioned on the ends of the sleeve to reduce friction between the ends of the sleeve and the end of an adjacent thrust bearing collar used to hold the sleeve in place on the drill pipe.

Abstract: A stabiliser is disclosed for stabilising a radially expandable tubular element extending in a wellbore drilled into an earth formation. The stabiliser comprises a radially expandable tubular member selected from a section of the tubular element and a sleeve surrounding the tubular element, and at least one stabiliser arm connected to the tubular member, each arm being movable from a radially retracted position to a radially extended position by the action of a spring force. The stabiliser further comprises locking means arranged to lock each arm in the retracted position when the tubular element is in the unexpanded form and to unlock the arm upon radial expansion of the tubular member so as to allow the arm to move to the extended position thereof.

Abstract: An adjustable down-hole tool, for example a drill-string stabiliser (10), comprises a body (12) having a through bore (16). A mandrel (18) is rotationally fixed but axially movable in the body, the mandrel being movable by fluid pressure in the tool against the action of a first return spring (44) between a first, activated position and a second deactivated position. A sleeve (66) is between shoulders (68, 69) on the body and mandrel. Castellations (18a,b, 69a,b) are on the mandrel and facing edge or edges of the sleeve so that, when the castellations are in phase the mandrel is prevented from travelling from said first to second position and when they are out of phase they interdigitate and the mandrel is not prevented from travelling from said first to second position. A control piston (36) is slidable in the mandrel, being movable by fluid pressure in the tool against the action of a second return spring (50).

Abstract: A drilling shaft deflection assembly for a drilling direction control device of the type comprising a rotatable drilling shaft and a housing for supporting a length of the drilling shaft for rotation therein. The deflection assembly is contained within the housing and is axially located between a first support location and a second support location for bending the drilling shaft between the first support location and the second support location. The deflection assembly includes a deflection mechanism for imparting lateral movement to the drilling shaft to bend the drilling shaft, a deflection actuator for actuating the deflection mechanism in response to longitudinal movement of the deflection actuator, and a deflection linkage mechanism between the deflection mechanism and the deflection actuator for converting longitudinal movement of the deflection actuator to lateral movement of the drilling shaft.

Abstract: A drill pipe protector having a tubular sleeve that is attached to a section of drill pipe and resides over the outer diameter of the drill pipe while moving within an associated well casing or well hole. The sleeve has low-friction end pads positioned on the ends of the sleeve to reduce friction between the ends of the sleeve and the end of an adjacent thrust bearing collar used to hold the sleeve in place on the drill pipe.

Abstract: A downhole drilling motor comprises a housing including an integral stabilizing configuration. The stabilizing configuration may include a number of ribs which project from the surface of the housing and run longitudinally or helically along the housing. The stabilizing configuration may be a result of the cross-sectional shape of the housing which may be substantially triangular or square such that the diameter of a circle which circumscribes the cross section of the housing is substantially the same as the diameter of the borehole within which the motor may be used.

Abstract: An adjustable down-hole tool, for example a drill-string stabiliser (10), comprises a body (12) having a through bore (16). A mandrel (18) is rotationally fixed but axially movable in the body, the mandrel being movable by fluid pressure in the tool against the action of a first return spring (44) between a first, activated position and a second deactivated position. A sleeve (66) is between shoulders (68, 69) on the body and mandrel. Castellations (18a,b, 69a,b) are on the mandrel and facing edge or edges of the sleeve so that, when the castellations are in phase the mandrel is prevented from travelling from said first to second position and when they are out of phase they interdigitate and the mandrel is not prevented from travelling from said first to second position. A control piston (36) is slidable in the mandrel, being movable by fluid pressure in the tool against the action of a second return spring (50).

Abstract: A centralizer apparatus for centralizing tubular casing in a borehole having two stop collars for securing to the casing in a spaced apart relationship and two moving collars, one slidably and rotatably coupled to each stop collar, a plurality of bow springs, each bow spring having a first end spaced apart from a second end, each bow spring biased outwardly from the center axis, the first ends connected to the first moving collar, the second ends connected to the second moving collar.

Abstract: A drill pipe protector having a tubular sleeve that is attached to a section of drill pipe and resides over the outer diameter of the drill pipe while moving within an associated well casing or well hole. The sleeve has low-friction end pads positioned on the ends of the sleeve to reduce friction between the ends of the sleeve and the end of an adjacent thrust bearing collar used to hold the sleeve in place on the drill pipe.

Abstract: There is disclosed an improved centraliser (210) for centralisation of tubulars (250) such as casings, liners, production tubing, production screens and the like, in oil/gas wells. Known centralisers are of a “unitary construction”, i.e. made in one piece fro m one material. This provides numerous problems in the prior art since the chosen material must provide conflicting characteristics at different times and places. Accordingly, the invention provides a centraliser (210) comprising a tubular body (214), a portion of an outermost surface (212) of said tubular body (214) being formed from a first material and a portion of or adjacent to at least one end (218) of said tubular body and/or a portion of an innermost surface (222) being formed from second material(s), the first material having a lower Youngs modulus than the second material(s).

Abstract: A one-piece wire guard device formed of non-metallic material for use in wells includes an inner ring having a split therein defining an opening and having a portion of reduced thickness defining a hinge is disclosed. Arcuate sections are disposed concentrically outwardly of the inner ring and are connected to the latter by ribs. The ribs, arcuate sections and inner ring cooperate with each other to define openings for accommodating electric wires, ropes and the like therethrough. A guard device may be flexed about its hinge from a normally closed condition to an open position to permit a drop pipe to be inserted through the opening defined by the split. Releasably locking means, including an elongated locking element, lock the guard device upon the drop pipe. Spacer tabs extend outwardly from the arcuate sections and engage a well casing to space the drop pipe from the casing and thereby prevent damage to the drop pipe, electrical wires, safety ropes and the like extending through the guard device.

Abstract: A stabilizer for a drill string and drill bit is mounted behind the drill bit in the drilling assembly. The stabilizer comprises a tubular body having one or more stabilizer blades mounted thereon. The stabilizer blades extend radially outwardly from the stabilizer body. In a first position, the stabilizer blades are in vertical axial alignment behind the drill bit. Drill string pressure is utilized to release a locking mechanism permitting relative rotation between the stabilizer blades and the stabilizer body thereby rotating the stabilizer blades to a second position providing stabilization for the drill string and drill bit.

Abstract: The present invention comprises a centraliser (10) for mounting on a tubular member such as a section of casing, together with one or more stops (42, 48) for retaining the centraliser thereon. The stops (42, 48) are provided with profiles for engaging the centraliser to restrict rotation thereof. The centraliser (10) may be selectively permitted or restricted from rotation by selection of appropriate stops, and by relative movement of the stops and centraliser on the tubular. Certain embodiments of the centraliser (10) may also include blades (14) on the body thereof, the blades being formed such that the velocity and kinetic energy of fluid flow across the blades is altered, so reducing settling of drill cuttings within the bore and on the centraliser.

Abstract: An expandable reaming tool including at least two reamer pads connected to a tool body. The reamer pads are adapted to be displaced between a retracted position and an expanded position. At least one spiral blade is formed on at least one reamer pad. A plurality of cutting elements are disposed on the at least one spiral blade.

Abstract: A centraliser primarily for use when casing an oil or gas well, the centraliser having low frictions coatings (19) or sliders (129) on the outer surface thereof.

Abstract: The invention refers to a drilling tool and method that, among other aspects, provides for a sleeve with expansible pads for positioning the drilling tool in the desired direction during drilling. The pads are hydraulically expanded and retracted by a valve system which selectively diverts mud flowing through the tool to the desired pads. The tool may also be provided with a flexible tube connecting the sleeve to drilling tool for maneuvering along deviations or curves in the wellbore.

Abstract: A drill bit for drilling into earth formations comprising an elongated body having spiral contoured stabilizers for up to a 360-degree stabilization to protect the cutting cones, the elongated body has multiple adjustable openings or nozzles to direct the pressurized fluid medium first to the cutting cone area and bottom of the drill hole to convey the dust and cuttings up the bore hole, a second, adjustable opening or nozzle adds more pressurized fluid means spirally up the contoured annular area in the stabilizer area, and a third, adjustable opening or nozzle at the upper end of the contoured stabilizer to add more pressurized fluid means in the drill pipe annular area to convey the dust and cuttings to the surface of the bore hole, the elongated body has replaceable cutting cones, and bearings and shank assemblies for rebuilding to original specifications.

Abstract: The drill device has a body with a front end and a rear end and which is connectable to the shaft of a drilling apparatus. A plurality of angularly spaced apart slots are formed in the exterior of the device which extend between the front and rear ends. Each slot has a lip extending from each of its front and rear ends respectively. A cutting member is provided for each of the slots with each cutting member having a connecting portion located in one of the slots and having a forward end and a rearward. Each connecting portion has a hook near its front and rear ends respectively for connection to the lips of the slot in which it is located.

Abstract: A friction and/or torque reducing drillstring component has a one-piece mandrel body 5 with a mandrel body recess 13c considerably smaller than mandrel upper neck 13a and mandrel body lower neck 13b, dressed with an outer sleeve 18 which is interlocked with a two-piece inner bearing 20 through several integral dove-tailed splines 22b and grooves 22a. The combination of the outer sleeve 18 and inner bearing 20 is restricted in vertical movement over the said mandrel body 5 by an integral, optionally spirally, bladed first stop 15 and a removable second stop 16. The removable second stop 16 is locked onto the mandrel body upper neck 13a by means of threaded retaining bolts 24. Once the second stop 16 is removed, the one-piece outer sleeve 18 is retractable over the mandrel body upper neck 13a to allow the removal of the two-piece inner bearing 20. A second inner bearing 155 may also be provided.

Abstract: The present invention provides apparatus for power transfer over a nonconductive gap between rotating and non-rotating members of downhole oilfield tools. The gap may contain a non-conductive fluid, such as drilling fluid or oil for operating hydraulic devices in the downhole tool. The downhole tool, in one embodiment, is a drilling assembly wherein a drive shaft is rotated by a downhole motor to rotate the drill bit attached to the bottom end of the drive shaft. A substantially non-rotating sleeve around the drive shaft includes a plurality of independently operated force application members used to exert the force required to maintain and/or alter the drilling direction. In the preferred system, one or more mechanically operated devices such as hydraulic units control the force application members. A transfer device transfers electrical power between the rotating and non-rotating members, and the electric power is converted directly to mechanical power.

Abstract: The apparatus includes an annular cam rotatably located in a housing with a drill shaft extending through the cam and housing. The shaft can be rotated for drilling purposes and be moved longitudinally in the housing for shifting purposes. The cam has grooves in its outer surface for receiving a cam follower carried by the shaft which rotates the cam as the shaft is moved longitudinally for shifting purposes. The shaft may be moved longitudinally in one direction to a position to engage members of a clutch such that when the shaft rotates, it rotates the housing. The shaft is movable in an opposite direction to disengage the clutch members and then is movable to locate the cam follower in the groove at different positions to allow the operator to control the longitudinal position of the shaft for turning purposes or for drilling straight.

Abstract: A drill pipe protector assembly for providing hydraulic lift and improved sliding lubrication to a drill string. The protector defines a tubular sleeve that is attached to a section of drill pipe and resides over the outer diameter of the drill pipe while moving within an associated well casing or well hole. The sleeve is adapted to provide hydraulic lift and sliding lubrication relative to the well casing and thus, increase the proclivity of the drill pipe to slide down the hole while also reducing the development of cutting dams. The sleeve includes a plurality of radially oriented openings which direct drilling mud from the annular space between the sleeve and drill pipe to the annular space between the sleeve and the casing or outer well wall. The sleeve also includes a plurality of wedge shaped longitudinal channels in communication with the radial openings.

Abstract: A drill pipe protector assembly for providing hydraulic lift and improved sliding lubrication to a drill string. The protector defines a tubular sleeve that is attached to a section of drill pipe and resides over the outer diameter of the drill pipe while moving within an associated well casing or well hole. The sleeve is adapted to provide hydraulic lift and sliding lubrication relative to the well casing and thus, increase the proclivity of the drill pipe to slide down the hole while also reducing the development of cutting dams. The sleeve includes a plurality of radially oriented openings which direct drilling mud from the annular space between the sleeve and drill pipe to the annular space between the sleeve and the casing or outer well wall. The sleeve also includes a plurality of wedge shaped longitudinal channels in communication with the radial openings.

Abstract: The friction-reducing drill pipe component in the form of a sub (10) is adapted to form part of a drill string. The sub (10) comprises a tubular mandrel (12) having first and second ends for connection to adjacent components of the drill string. A sleeve (18) is mounted on the mandrel (12), and first and second stops on the mandrel (16, 20) restrain the sleeve (18) against axial movement relative to the mandrel (12). One of the stops (20) is removable or retractable to permit the sleeve (18) to be removed over the first end of the mandrel.

Abstract: A centralizer for use in centralizing casing or other tubulars such as tubulars in an oil or gas well comprising an annular body with a bore extending through the body and one or more blades, the centralizer being adapted to fit around a tubular to be centralized, and comprising a tempered metal such as austemperized ductile iron (ADI).

Abstract: In one embodiment, the invention provides a drilling assembly comprising a motor, a reaming stabilizer and a drill bit. The motor is adapted to be attached to a drill string, the motor includes a drive shaft with a mandrel mounted at the bottom end of the shaft. The reaming stabilizer is attached to the shaft of the motor by the mandrel, so that the stabilizer may be rotatably driven by the motor. The drill bit is attached to the stabilizer to be rotatably driven by the stabilizer. The stabilizer is sized so that the overall length of the drilling assembly is increased by a maximum of about 16 inches. Greater lengths may reduce motor bearing life, adversely affect the steering of the tool or result in drive shaft breakage with consequent loss of the drill bit and stabilizer in the hole.

Abstract: A fitting for reducing friction between a drilling string and the wall of a well. In a first aspect the fitting has recesses (6) provided along the bore of the fitting to lubricate the interface between the fitting and the drill string to minimise friction. In a second aspect a fitting is provided on a drill string having rotatable roller means (21) which can rotate about a point of rotation (23) so as to minimise both axial and rotational friction. According to a third aspect the fitting comprises an inner section (30) secured to a drill pipe (35) or other fitting and an outer section (31) rotatable about the inner section (30). Preferably a sealed bearing (36, 42-47, 37, 38) is provided between the inner section (30) and outer section (31).

Abstract: Drill pipe protection rings for filling external identification slots in drill pipe tool joints prevent damage to the internal seals of a drilling head. The rings are formed from resilient elastomeric materials. In cross-section, each ring has slightly convex inner and outer surfaces, and a series of circumferentially spaced-apart, hemispherical bumps located along its inner surface. One ring is mounted within each slot on each drill pipe section. The rings stretch slightly while being installed, but form a tight fit once they are properly seated. When installed, the outer surfaces of the rings will protrude slightly outward from or beyond the slots. The hemispherical bumps help align and center the rings within the slots. Without the rings, sharp edges of the slots on the drill pipe tool joints could cause severe damage as they passed through the drill head. However, with the rings, the outer surfaces of the slots are substantially filled to prevent their edges from cutting or gouging the elastomers.