Abstract: A hydraulically powered tractor adapted for advancement through a borehole including an elongate body, aft and forward gripper assemblies, and a valve control assembly housed within the elongate body. The aft and forward gripper assemblies are adapted for selective engagement with the inner surface of the borehole. The valve control assembly includes a gripper control valve for directing pressurized fluid to the aft and forward gripper assemblies. The valve control assembly also includes a propulsion control valve for directing fluid to an aft or forward power chamber for advancing the body relative to the actuated gripper assembly. Aft and forward mechanically actuated valves may be provided for controlling the position of the gripper control valve by detecting and signaling when the body has completed an advancement stroke relative to an actuated gripper assembly.

Abstract: A device for anchoring a drill string in a borehole an anchoring member connected to the drill string, the anchoring member being movable between a retracted position in which the anchoring member is retracted from the borehole wall, and, an extended position in which the anchoring member is extended against the borehole wall so as to anchor the drill string to the borehole wall, and an activating member operable to move the anchoring member from the extended position to the retracted position by the action of pressure of drilling fluid present in the borehole.

Abstract: The present invention relates to an apparatus and method for isolating a wellbore condition such as formation pressure during a wellbore operation. The invention has particular application in connection with underbalanced drilling. In one arrangement, a formation isolation apparatus is provided that serves as a selectively actuatable plug. The plug in one aspect is selectively set and released by a setting/releasing tool. The setting/releasing tool includes a system for setting the plug in the wellbore, and a system for releasing the plug from the wellbore. The setting/releasing tool is releasably connected to the plug. Thus, after the plug has been set, the setting/releasing tool may be removed from the wellbore. The plug includes a flapper valve that is restrained in its open position by the setting/releasing tool. Removal of the setting/releasing tool from the wellbore allows the flapper valve to close, thereby isolating pressures in the wellbore below the flapper valve. The plug is wireline retrievable.

Abstract: A drilling apparatus that includes a formation fluid sampling and hydraulic testing tool for a drilling apparatus that includes a drilling string comprised of a drilling pipe and a drilling bit is provided. The tool is mounted on a string that comprises from top to bottom a pressure reduction valve, an expandible and collapsible packer bladder assembly, the sampling tool, and a lower expandible and collapsible packer bladder assembly, disposed between the drilling pipe and the drilling bit. Associated with the packer assemblies are pressure and vacuum storage devices for inflation and deflation respectively of the bladders of the packer assemblies.

Abstract: A gripper assembly for anchoring a tractor within a downhole passage and for assisting movement of the tractor within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A method and apparatus for delivering a well treatment fluid to a productive zone of a subterranean formation at the same time that a well bore is being drilled is provided. The method includes the steps of delivering a drill-in fluid to a drill bit drilling a well bore in, or adjacent to, the productive zone; removing drill cuttings from the well bore; and simultaneous with these steps injecting the treatment fluid into the productive zone. The apparatus includes at least three nested tubes, which form one internal flow path and two annuluses. The drill-in fluid and drill cuttings are delivered to, and removed from, the drill bit, respectively, through the internal flow path and one of the two annuluses. The treatment fluid is delivered to the subterranean formation through the remaining annulus and an expandable bladder mounted to the intermediate and outer tubes.

Abstract: The invention relates to equipment for drilling a vertical borehole in hard ground, the equipment comprising: casing put successively into place in the borehole; a drilling machine having a rotary cutting head and presenting a structural frame; torque and thrust transmission means having a first end secured to the structural frame of the drilling machine; and securing means for securing the second end of the torque and thrust transmission means in translation and in rotation to said casing.

Abstract: A drilling mud diverter and method of use for horizontal drilling operations wherein drilling muds are diverted to a single portal of the bore where the drilling muds are recovered for removal or reprocessing, the mud diverter having a diverter unit with a central cylindrical core with enlarged end caps and an inflatable bladder mounted on the core, the diverter unit having a bypass passage through the unit blocked by a pressure relief valve that allows drilling muds blocked by the diverter unit to pass through the unit only when a preset pressure is reached; the method of use including the procedure for installing the mud diverter into an enlarged bore using the drilling pipe and removing the mud diverter using the drilling pipe, cables or other alternative equipment.

Abstract: A hydraulically powered tractor includes an elongated body, two gripper assemblies, at least one pair of aft and forward propulsion cylinders and pistons, and a valve system. The valve system comprises an inlet control valve, a two-position propulsion control valve, a two-position gripper control valve, two cycle valves, and two pressure reduction valves. The inlet control valve spool includes a hydraulically controlled deactivation cam that locks the valve in a closed position, rendering the tractor non-operational. The propulsion control valve is piloted on both ends by fluid pressure in the gripper assemblies. The propulsion control valve controls the distribution of operating fluid to and from the propulsion cylinders, such that one cylinder performs a power stroke while the other cylinder performs a reset stroke. Each end of the gripper control valve is piloted by a source of high-pressure fluid selectively admitted by one of the cycle valves.

Abstract: A drilling system and method for drilling a borehole into an earth formation is provided. The drilling system comprises a drill string (1) having a lower section provided with a sleeve (7) which is radially expandable from a retracted mode in which the sleeve extends around said lower drill string section and is releasably connected thereto, to an expanded mode in which the sleeve is released from the lower drill string section and is expanded against the borehole wall. The drilling system further comprises control means (10) for selectively releasing the sleeve (7) from the lower drill string section and expanding the sleeve against the borehole wall.

Abstract: An apparatus for propulsion inside an oblong cavity, such as pipes or the like, is disclosed.

Abstract: A drilling apparatus that includes a formation fluid sampling and hydraulic testing tool for a drilling apparatus that includes a drilling string comprised of a drilling pipe and a drilling bit is provided. The tool is mounted on a string that comprises from top to bottom a pressure reduction valve, an expandible and collapsible packer bladder assembly, the sampling tool, and a lower expandible and collapsible packer bladder assembly, disposed between the drilling pipe and the drilling bit. Associated with the packer assemblies are pressure and vacuum storage devices for inflation and deflation respectively of the bladders of the packer assemblies.

Abstract: The present invention generally relates to an apparatus and method for sealing a tubular string. In one aspect, a drilling system is provided. The drilling system includes a rotating control head for sealing the tubular string while permitting axial movement of the string relative to the rotating control head. The drilling system also includes an actuating fluid for actuating the rotating control head and maintaining a pressure differential between a fluid pressure in the rotating control head and a wellbore pressure. Additionally, the drilling system includes a cooling medium for passing through the rotating control head. In another aspect, a rotating control head is provided. In yet another aspect, a method for sealing a tubular in a rotating control head is provided.

Abstract: A gripper assembly for anchoring a tractor within a downhole passage and for assisting movement of the tractor within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A device for anchoring a drill string in a borehole formed in an earth formation is provided. The device comprises an anchoring member connected to the drill string and being movable between a retracted position in which the anchoring member is retracted from the borehole wall and an extended position in which the anchoring member is extended against the borehole wall so as to anchor the drill string to the borehole wall, and an activating member operable to move the anchoring member from the extended position to the retracted position by the action of pressure of drilling fluid present in the borehole.

Abstract: A method and apparatus for under balanced drilling comprising a production casing extending vertically from the ground to the area where the drilling is taking place, a concentric casing mounted within the production casing and forming therewith an outer annulus, a concentric casing connecting at its lower end with an upper end of an injection tool, the injection tool having a lower end connecting with a packer assembly which includes a packer and slips, and a drill string having a drill bit at the lower end thereof extending downwardly through the concentric casing, the injection tool, and packer assembly to the area where the drilling is taking place, the injection tool having a generally cylindrical body and a plurality of spaced spiral flutes extending outwardly from the cylindrical body to the inner wall of the production casing and forming therebetween spiral openings through which fluid may be forced downwardly through the outer annulus and against the packer, each flute having an upwardly directed spi

Abstract: A gripper assembly for anchoring a tractor within a downhole passage and for assisting movement of the tractor within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A borehole tool including a tool body having and an anchoring mechanism, the anchoring mechanism having a drive mechanism including a motor, drive shaft, and clutch; an anchor arm moveable between first and second positions relative to the tool body; a push rod connecting the anchor arm to the drive mechanism; and a spring acting to bias the arm into a first position relative to the tool body. The push rod extends through the clutch mechanism and is engaged by the spring to bias the arm into the first position, and is also driven by the drive mechanism through the clutch to move the arm between the first and second position. The push rod may be connected to the anchor arm by a link. Measurement devices may be used to determine the position of the anchor arm or the tool body.

Abstract: The present invention generally provides a reduced downtime maintenance apparatus and method for replacing and/or repairing a subassembly in sealing equipment for oil field use. The invention allows the removal of rotating portions of a rotary drilling head without having to remove non-rotating portions. The reduction in weight and size allows a more efficient repair and/or replacement of a principal wear component such as a packer. Specifically, the packer in a rotary drilling head can be removed independent of bearings and other portions of the rotary drilling head. Furthermore, because of the relatively small size and light weight, the packer can be removed typically without having to use a crane to lift a rotary BOP and without disassembling portions of the drilling platform. In some embodiments, the packer can be removed with the drill pipe without additional equipment. Furthermore, the packer can be removed remotely without necessitating manual disengagement typically needed below the platform.

Abstract: Methods for reclaiming a borehole extending from an earth surface into the earth, part of which borehole is in a lost circulation zone. The methods include the steps of closing off the borehole to fluid flow above the lost circulation zone by installing a packer system with an inflatable packer element, inflating the inflatable packer element with cement, allowing the cement to set so that the inflatable packer effectively seals off the borehole to fluid flow, and then drilling out the inflatable packer. Such a method also may include a further operation conducted in the borehole within the lost circulation zone. The packer system comprises in one arrangement a packer body, an inflatable bladder around the packer body, a plurality of ribs mounted around at least a portion of the inflatable bladder, and a valve apparatus, all of which are fabricated from a drillable material.

Abstract: Canister, sealing method and composition for sealing a borehole. The canister includes a container with slurry inside the container, one or more slurry exits at one end of the container, a pump at the other end of the container, and a piston inside that pushes the slurry though the slurry exit(s), out of the container, and into a borehole. An inflatable packer outside the container provides stabilization in the borehole. A borehole sealing material is made by combining an oxide or hydroxide and a phosphate with water to form a slurry which then sets to form a high strength, minimally porous material which binds well to itself, underground formations, steel and ceramics.

Abstract: A well bore pressure containment device is provided. Operating as a single stripping and containment device compatible with a wide range of tool string and tubing sizes, the containment device may be integrated with rotating pressure control systems, and be used during completion and work over operations. The containment device has a spool, and a flexible bladder extending about the interior of the spool. The bladder may be controllably deformed to seal against a tool string passing through the device using an inwardly directed pressure, which preferably is exerted by a fluid in the interstitial space between the spool and the bladder.

Abstract: An apparatus for in situ borehole testing having a drill string with drill pipe and drill bit. An upper sleeve and lower sleeve are telescopically coupled together. A valve seat is located in an interior passage and closes the interior passage when a valve member is seated in the valve seat. A plurality of separate inflatable packers are coupled to the lower sleeve and activated when the valve member is seated in the valve seat. A latching collet having teeth positively interlocks with spline teeth affixed to the inner wall of the upper sleeve. A hydraulic valve assembly is attached to the lower sleeve and is activated by fluid in one of a plurality of separate fluid chambers which communicate with and inflate the separate packers.

Abstract: The present invention provides continuous or near continuous motion drill strings which include motion sensitive and other MWD sensors which take stationary measurements while the drilling assembly is continuing to drill the wellbore. For simultaneous continuous drilling and stationary measurements, the present invention provides a drilling assembly wherein a force application system almost-continuously applies force on the drill bit while maintaining a housing or drill collar section stationary. Motion sensitive sensors carried by the drill collar take stationary measurements. A steering device between the drill bit and the force application system maintains drilling of the wellbore along a prescribed well path.

Abstract: A gripper assembly for anchoring a tractor within a downhole passage and for assisting movement of the tractor within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A packerfoot includes a bladder assembly comprising an elongated generally tubular inflatable bladder having ends bonded to generally rigid bladder attachment portions. The bladder includes end portions bonded to the bladder attachment portions and a central inflatable portion. The bladder comprises multiple layers of rubber, one or more of which are reinforced by fibers, preferably S-glass. At each end of the bladder, the layers terminate at different longitudinal positions, forming annular steps on the exterior surface of the bladder. Conforming annular steps are formed on the interior surface of the bladder attachment portions. The bladder ends are bonded to the bladder attachment portions such that the annular steps of the bladder conform to the annular steps of the bladder attachment portions. The total bond length of the bladder to the bladder attachment portions is greater than or equal to twice the length of the inflatable portion of the bladder.

Abstract: A downhole drilling tractor for moving within a borehole comprises a tractor body, two packerfeet, two aft propulsion cylinders, and two forward propulsion cylinders. The body comprises aft and forward shafts and a central control assembly. The packerfeet and propulsion cylinders are slidably engaged with the tractor body. Drilling fluid can be delivered to the packerfeet to cause the packerfeet to grip onto the borehole wall. Drilling fluid can be delivered to the propulsion cylinders to selectively provide downhole or uphole hydraulic thrust to the tractor body. The tractor receives drilling fluid from a drill string extending to the surface. A system of spool valves in the control assembly controls the distribution of drilling fluid to the packerfeet and cylinders. The valve positions are controlled by motors. A programmable electronic logic component on the tractor receives control signals from the surface and feedback signals from various sensors on the tool.

Abstract: A test, drill and pull system for testing a well formation or zone of interest and further drilling of the well in a single trip into the wellbore. The system includes a surface readout tester valve, a rotation-operated reversing valve, a resettable packer, a packer lockout, a perforated anchor and a drill bit. In operation, the apparatus is run into the bottom of the well adjacent to the formation or zone of interest and the packer set and unset as desired. With the packer set, a surface readout tester valve probe is lowered into the apparatus on a wireline and latched into the tester valve so that multiple testing operations may be carried out if desired. After testing, the fluid recovery may be reversed out and analyzed by actuating the reversing valve by rotation of the tool string. Further, rotation engages the packer lockout such that when weight is picked upon the packer, the packer cannot be reset.

Abstract: A borehole tool, such as a seismic shuttle-type logging tool, including a tool body having at least one sensor package and an anchoring mechanism, the anchoring mechanism having a drive mechanism including a motor, a drive shaft and a clutch; an anchoring arm moveable between first (extended)and second (retracted) positions relative to the tool body; a push rod connecting the anchoring arm to the drive mechanism; and a spring acting to bias the arm into a first position relative to the tool body. The push rod extends through the clutch mechanism and is engaged by the spring to bias the arm into the first position, and is also driven by the drive mechanism through the clutch to move the arm between the first and second positions. The spring is a coil spring surrounding the drive mechanism and acting on the push rod directly.

Abstract: Subsurface wellbore conditions are measured directly in the wellbore while the fluid circulation system is not pumping. The measured values are recorded at the subsurface location and subsequently transmitted to the well surface when circulation is resumed using fluid pulse telemetry (FPT). Real-time measurements made/when the fluids are circulating are transmitted real time using FPT. Axially spaced measurements are used to obtain differential values. The apparatus of the invention comprises an assembly carried by a drill string that is used to selectively isolate the area within the well that is to be evaluated. The apparatus includes an assembly having axially spaced inflatable well packers that are used to isolate an uncased section of the wellbore. The apparatus is equipped with self-contained measuring and recording equipment, a fluid receiving reservoir, circulation valving, measurement while drilling equipment, and automated controls.

Abstract: The invention relates to a jacket tube (6) for a device for drilling holes and forming an anchorage in the earth or rock. The inventive jacket tube (6) is coupled with a drill pipe (3) and/or a drill bit (1) or a drill hammer and is configured with a plurality of through openings across its periphery. Once the borehole (2) has been made, or after an anchor has been introduced, the jacket tube can be filled with a hardenable suspension. According to the invention, the jacket tube consists of at least one expanded metal element (6) which has evenly distributed through openings (9) and connecting elements (7, 8), especially sleeves, at the ends for connecting to a drill bit (1) and/or other jacket tube elements (6). The borehole (2) is therefore easy to produce and the jacket tube (6) can be anchored securely.

Abstract: A conveyance apparatus for conveying at least one logging tool through an earth formation traversed by a horizontal or highly deviated borehole. The conveyance apparatus comprises a pair of arcuate-shaped cams pivotally mounted to a support member, a spring member for biasing the arcuate surface of each cam into contact with the borehole wall, and actuators operatively connected to each cam. A logging tool is attached to the conveyance apparatus. When either actuator is activated in a first direction, the cam connected to the activated actuator is linearly displaced forward and the arcuate surface of the cam slides along the borehole wall. When either actuator is activated in a second direction, the activated actuator pulls the connected cam backwards and the spring member thereby urges the arcuate surface of the cam to lock against the borehole wall.

Abstract: Subsurface wellbore conditions are measured directly in the wellbore while the fluid circulation system is not pumping. The measured values are recorded at the subsurface location and subsequently transmitted to the well surface when circulation is resumed using fluid pulse telemetry (FPT). Real-time measurements made when the fluids are circulating are transmitted real time using FPT. Axially spaced measurements are used to obtain differential values. The apparatus of the invention comprises an assembly carried by a drill string that is used to selectively isolate the area within the well that is to be evaluated. The apparatus includes an assembly having axially spaced inflatable well packers that are used to isolate an uncased section of the wellbore. The apparatus is equipped with self-contained measuring and recording equipment, a fluid receiving reservoir, circulation valving, measurement while drilling equipment, and automated controls.

Abstract: An improved cage slip system is disclosed. The cage is constructed so that the cones which actuate the slips extend into the cage openings. The radial extension of the slips is limited so as to retain them if they are extended in an unsupported situation. The cones have a maximum outside dimension equal to the outside dimension of the cage so as to increase the rating of the slips by increasing the bearing area of the cones on the slips. The beneficial features of the cage design are retained while a greater degree of radial expansion of the slips is possible allowing minimization of tool inventory for situations where a lighter wall casing requires further slip extension.

Abstract: A conveyance apparatus for conveying at least one logging tool through an earth formation traversed by a horizontal or highly deviated borehole is disclosed. The conveyance apparatus comprises a pair of arcuate-shaped cams pivotally mounted to a support member, means for biasing the arcuate surface of each cam into contact with the borehole wall, and actuators operatively connected to each cam. A logging tool is attached to the conveyance apparatus. When either actuator is activated in a first direction, the cam connected to the activated actuator is linearly displaced forward and the arcuate surface of the cam slides along the borehole wall. When either actuator is activated in a second direction, the activated actuator pulls the connected cam backwards and the biasing means thereby urges the arcuate surface of the cam to lock against the borehole wall.

Abstract: This invention relates to a friction rock stabilizer which includes an elongated tendon tube which is reduced in cross-sectional dimension over a portion of its length towards one end of the tube, a slot which extends over at least the unreduced length of the tube and a radially extending stop which is located on the reduced dimension portion of the tube for supporting a face washer on the stabilizer. Preferably, the reduced cross-sectional length of the tube is parallel sided and is conveniently circular in cross-section.

Abstract: A rock drill guide tool comprises a sleeve arrangement (8) placed around a tubular drill tube (9) which rotates during a drilling operation and through which drilling liquid is supplied under pressure during drilling intervals. The sleeve arrangement includes a plurality of support units (15, 16) which can be projected out into contact with the wall of a drill hole and which are placed circularly in the sleeve arrangement. The support units (15, 16) are placed in at least two ring sections of the sleeve arrangement and are provided with elements (19, 20) which project out against the wall of a drill hole. These elements engage the rock so as to cut grooves into the wall of a drill hole as the drill is moved down during a drilling operation.

Abstract: The invention provides a tractor for locomoting a drilling apparatus. The tractor includes a retractable body for transporting and pressurizing a drill attached to a front drilling end of the retractable body. The retractable body is longitudinally extended and contracted for length adjustment. A drill stabilizer is attached to a rear trailing end of the retractable body. The drill stabilizer is extended to secure said retractable body during drilling and retracted for allowing movement of the rear trailing end of the retractable body. A position stabilizer is attached to the front drilling end of the retractable body. The position stabilizer is transversely extendable against the sidewalls of the drill hole for periodically stabilizing the retractable body. The position stabilizer retracts for operation of the drill when the drill is stabilized with the drill stabilizer.

Abstract: An apparatus for forcing a member or device, such as a sample tube or seismic or geological instrument, through a material such as soil along a selected line of action. The apparatus includes a derrick with first and second plates mounted thereto, the second plate having a locking dog extending through a hole therein for engaging the material, and the first plate being provided with a hydraulic cylinder or other device for forcing the member through the material. The first plate is also provided with an extruder head for releasably mounting the sample-containing sample tube thereto, and the hydraulic cylinder is provided with a plunger releasably mounted to the ram thereof for extruding the sample from the sample tube. The locking dog positively engages the material to provide an apparatus for transmitting the reactive forces resulting from forcing the member through the material to the material.

Abstract: A zone isolator module for use on a penetrometer comprises a tubular body having an annular recess in an exterior wall thereof, an elastomer membrane fixed in the annular recess and adapted to lie against an inner surface of the recess, a sleeve slidably disposed on the tubular body and slidably movable between a first position in which the sleeve completely covers the recess, and a second position in which the sleeve is substantially removed from the recess, and the body having an opening extending outwardly from an axial central bore therethrough to the inner surface of the recess, whereby fluid flowed through the bore and the opening operates to expand the elastomer membrane against the sleeve when the sleeve covers the recess and to expand the elastomer membrane beyond the exterior wall of the body when the sleeve is substantially removed from the recess.

Abstract: A drill string anchor for use in a well bore, the anchor having a body, a through bore and a plurality of anchor assemblies, each assembly comprising an anchor member, a piston supported within a body and a biasing means. The piston is initially radially movable in response to an initiating fluid pressure in the through bore causing its movement from a first retracted position to a second extended position in which the piston drives the anchor member into contact with the wall of the well bore. The biasing means acts to provide a force biasing the piston towards the first retracted position.

Abstract: A down reaming apparatus has an upper stabilizer which supports the down reaming apparatus in the bored hole. A plurality of shoe assemblies are radially attached to the hub of the upper stabilizer. The shoe assemblies are biased against a bored shaft wall by pressurized cylinders which allow limited return movement with resistance of the shoe assemblies. A weight assembly comprising a plurality of stacked plates is secured to the frame of the down reaming apparatus and has manways therethrough which allow passage of workers. A lower stabilizer provides additional support for the down reaming apparatus. The lower stabilizer also includes shoe assemblies that are biased against the bored shaft wall by a pressurized cylinder.

Abstract: The invention relates to a clamp mechanism that can be used to attach or temporarily support objects inside of tubular goods. The clamp mechanism can also be modified so that it grips objects. The clamp has a self-centering feature to accommodate out-of-roundness or other internal defections in tubular objects such as pipe. A plurality of clamping shoes are expanded by a linkage which is preferably powered by a motor to contact the inside of a pipe. The motion can be reversed and jaw elements can be connected to the linkage so as to bring the jaws together to grab an object.

Abstract: An orientation mandrel rotatable in an orientation body for providing rotational orientation and actuated by a hydraulic piston controlling the position of a helix. A thruster may be connected to the orientation mandrel and is adapted to hydraulically engage the well bore by plurality of elongate gripping bars. An annular thruster piston is hydraulically and longitudinally movable in the thruster body for extending the thruster mandrel outwardly from the thruster body. However, the orientating tool and thruster may be used separately.

Abstract: A drilling tool, for example a core barrel inner tube assembly or a drilling bit, is attached to the inner end of a latch body which is removably seatable on a landing shoulder of a drill string. A latch retractor is mounted to the latch body for limited axial movement and has a latch assembly chamber opening inwardly to the closed end of the tubular portion of the latch body. The latch assembly includes a rigid transverse link that at opposite ends dependingly pivotally mount a pair of latches, there being no mechanical attachment of the assembly to the retractor or latch body. A transverse stop member limits the latch lateral sections movement inwardly toward the other from a latch seated position to a latch retracted position. At the inner end of the retractor, there are angularly spaced flanges extending radially toward the other in the chamber for retracting the latches as the retractor is withdrawn. The flanges are spaced to permit the assembly being extended therebetween and into the chamber.

Abstract: A self-propelled, pneumopercussive, cyclic action, ground penetrating machine (200) has decreased energy consumption and increased average working velocity compared to conventional machines. This is obtained in part by a valve-operated air-distribution mechanism (203) having separate forward and reverse compressed air supply lines (35, 37), which mechanism (203) does not limit the length of the forward and backward strokes of the striker (202). This mechanism allows the backward stroke chamber (75) to be connected with the atmosphere during the entire forward stroke of the striker (202). This eliminates generation of an air buffer in the backward stroke chamber (75) and, consequently, the striker (202) does not lose part of its kinetic energy before impact.

Abstract: A pressure actuated, telescoping subassembly is supported by a pipe string to axially move an attached member within a wellbore. Increasing fluid pressure to the subassembly actuates a telescoping action, axially moving the attached member but not the supporting pipe string. Motion can be used during rotary drilling or running of tubulars into a drilled borehole portion. Pressure actuation provides a means to remotely apply axial force near the member, such as a tool or drill string portion. Moving only the member instead of the entire drill string and member lowers the total force required to move members and provides a new means to chase drill bits and apply constant drilling forces. This minimizes the risk of pipe string overloading and buckling, exceeding rig weight limitations, and tool bit damage.

Abstract: A device for guiding a drilling tool into a well and for exerting a hydraulic force on the drilling tool includes a tubular body and an outer sleeve rotating about the body and longitudinally displaceable with respect to the body. Also, the device includes radially displaceable pistons, in an extension position, that come into anchoring engagement with the wall of the well and immobilize the external sleeve, as well as a jack to displace the body and the drilling tool integral therewith with respect to the external sleeve and to exert a pushing force onto the tool. Hydraulic circuits and appropriate control assembly are also provided for controlling the execution of a series of successive cycles of anchoring of the external sleeve in the well and of displacement of the drilling tool with respect to the external sleeve.

Abstract: There is provided a new and useful coring assembly for mounting on the end of a drill string and comprising a core barrel; abrading means on at least a part of the core barrel; a reaming collar mounted about a lower section of the core barrel and selectable between a first condition in which the collar is rotatable with the barrel and a second condition in which the collar is rotatable relative to and slidable longitudinally relative to the core barrel; a housing suspended from the core barrel; a deflection crank extending between the housing and the core barrel; and means within the housing for transferring power from a power source to the crank for selectively rotating the crank for moving the core barrel between a first position in which the core barrel and the housing are aligned and a second position in which the barrel and the housing are not aligned.

Abstract: A method for obtaining in-situ stress measurements in a well is accomplished by installing a membrane packer on a drill string. The packer membrane is attached near the drilling tool and is capable of being radially expanded by fluid pressure to abut against the borehole. When a measurement of the in-situ stress is desired, a 3 way valve is actuated to divert drill string fluid into the packer until the membrane contacts the borehole. Further increments of fluid addition at this point are accomplished only by large increases in inflation fluid pressure. Pressure is increased (with little increase in volume) at a ramp rate until it reaches a value equal to the least principal stress, at which point the formation microfractures. The microfracture(s) result in a decreased pressure and/or volume ramp rate, which indicate their presence. Further pressurization would generate similar indications of fractures resulting from intermediate and maximum principle stresses.