Abstract: A modular reaming device incorporable into a tubular string. The modular reamer can include a tubular body having a first end and a second end and an internal bore, the internal bore extending longitudinally through the tubular body from the first end to the second end. The tubular body has an external surface with an outer diameter with cutting elements extending from the tubular body beyond the outer diameter of the tubular body for engagement with a bore hole sidewall. Each of the first and second ends have a coupling for coupling engagement with a tubular string.

Abstract: A system includes a downhole tool having multiple electric leads. The system also includes a release device that includes an outer shell configured to mechanically couple to the downhole tool, and the outer shell is configured to form a cavity that is fluidly separate from wellbore fluids contained within a wellbore while the outer shell is mechanically coupled to the downhole tool. The release device also includes a contact block configured to electrically couple to the multiple electric leads. In addition, the contact block is configured to electrically decouple from the multiple electric leads while the outer shell remains mechanically coupled to the downhole tool. Further, the contact block is configured to remain in the cavity after electrically decoupling from the plurality of electric leads.

Abstract: Mitigating drilling circulation loss can be implemented as a wellbore drilling system that includes a drilling liner and a drill head assembly. The drilling liner is configured to be positioned in a lost circulation zone of a subterranean formation in which a wellbore is being drilled. The drilling liner is configured to flow wellbore drilling fluids from a surface of the wellbore to the subterranean formation while avoiding the lost circulation zone. The drill head assembly is attached to a downhole end of the drilling liner, and is configured to drill the subterranean formation to form cuttings, receive the wellbore drilling fluids, and flow the cuttings and the wellbore drilling fluids into the drilling liner while avoiding the lost circulation zone and towards the surface of the wellbore.

Abstract: A method and apparatus for setting a subsurface device in a wellbore. A downhole power unit comprises a power rod and a drive shaft. The power rod comprises a hollow interior. The drive shaft is located within the hollow interior, and the power rod is operable to selectively engage a subsurface device to be positioned downhole.

Abstract: A drill string for drilling a subterranean wellbore includes a shaft connectable to a first drill string portion and a housing connectable to a second drill string portion. A torque relief section is disposed between the shaft and housing. The torque relief section includes a slip section operable to slip and release torque buildup when torque applied between the shaft and housing exceeds a threshold torque. The threshold torque of the torque relief section is selected to be within the range of about 110% and 150% of the operating torque and below the peak operating torque for the drill string.

Abstract: A device for boring a well. The device is attached to a motor that has a power shaft for imparting rotational movement. The device includes a driver operatively connected to the power shaft, with the driver containing a cylindrical body, a first bit having a first end connected to the driver so that rotational movement of the driver is imparted to the first bit, and a sleeve disposed about the power shaft. The device further includes a housing disposed about the driver, and a second bit attached to the housing. Through engagement of cogs and pinions, rotation of the first bit in a first direction using the driver causes counter rotation of the second bit in an opposite direction, significantly reducing or eliminating reactive torque produced during drilling.

Abstract: An earth boring bit assembly has a tubular mandrel carried by a casing shoe at the lower end of a string of casing. The casing shoe has stabilizer blades spaced circumferentially apart from each other. A cutter arm seat is formed on the leading edge of each blade at a lower end of the casing shoe. Windows are formed in and spaced circumferentially around the mandrel. A cutter arm is pivotally mounted within each window of the mandrel and movable from an extended position located within one of the cutter arm seats to a recessed position within its window. The cutter arm seats support the cutter arms for torque and axial weight. A sleeve inside the mandrel prevents the cutter arms from pivoting to a recessed position until the sleeve is moved to a released position.

Abstract: A device for boring a well. The device is attached to a motor that has a power shaft for imparting rotational movement. The device comprises a driver operatively connected to the power shaft, with the driver containing a tubular body, a first bit having a first end connected to the driver so that rotational movement of the driver is imparted to the first bit, and a sleeve disposed about the power shaft, and wherein the sleeve has a radial shoulder. The device further comprises a housing disposed about the driver and a second bit attached to the housing. A plurality of nozzles is operatively placed within the driver, and the nozzles deliver fluid flow to the second bit. The device may further include a planetary gear anchored to the radial shoulder, and wherein the planetary gear is adapted for imparting rotation from the driver to the housing in a counter radial direction.

Abstract: A down hole running tool 14 travels in a first direction through a drill pipe for installing bit segments 18 at the end of a drive sub 12 attached to the drill pipe. The tool 14 includes a first portion 82 and a second portion 84 which is retractably coupled to a leading end of the first portion 82. The first portion 82 includes a tubular extension 134 which receives a spigot 136 that extends from an upper end of the second portion 84. A pin 138 extends transversely through the tubular extension 134 and resides within opposing slots 140 formed in the spigot 136. There is a stepped reduction in the internal diameter at the lower end of the tubular extension 134 so as to form a cup-like structure 146. A spring 168 is disposed about the spigot 136 and has an upper end seated in the cup-like structure 146 and a lower end bearing against an upper face 170 of the second portion 84. The spring 168 is biased so as to push the first and second portions 82 and 84 apart in the longitudinal direction.

Abstract: A retraction system allows disengagement of retrieval latch dogs of a down hole running tool from a bit locking sleeve. The locking sleeve is slidably retained within a drive sub and includes a pair of slots which are engaged by the retrieval latch dogs when the tool is used to retrieve bit segments from the drive sub. The retraction system includes a sleeve which is slidably mounted on a main body of the tool and spring which is biased to push the sleeve over the retrieval latch dogs. The sleeve has a pair of diametrically opposed slots through which the retrieval latch dogs can extend for contacting the inner surface of the drive sub. The retraction system also includes a length of the inner surface of the drive sub which is made of progressively reducing diameter in the direction of retraction of the tool from the drive sub. The upper end of each slot is provided with a bevel for directing the retrieval latch dogs in the inward direction.

Abstract: Drill tools with eccentric bits for drilling a hole having a large diameter generally include a bit for swinging out to an eccentric position for drilling, and for swinging into a non-eccentric position for removal from a tubular casing. Relatively complicated structures are required for effecting bit movement, and it is often difficult to remove the bit for replacement or repair.

Abstract: A drilling tool is followed by a casing tube (11) down the drilled hole. The mouth of the casing tube (11) centers rotatably a guide member (10) which receives rotation and impact energy via the interior of the casing tube (11). A drill bit (20) consists integrally of an axially protruding pilot portion (23), a sidewise projecting eccentric portion (22) and a rear shaft (21). The shaft (21) extends pivotally and axially movably into an eccentrically disposed bore (24) in the guide member (10). Axially spaced peripheral end grooves (30,32) extend in opposite direction from an axial cam groove (31) on the shaft (21) and are engaged by a follower (28) in the guide member (10) defining positively the axial and angular movability and positions thereof relative to the drill bit (20). In the forward end groove (32) the follower (28) maintains the drill bit (20) axially in drilling position (FIG.

Abstract: A core sampling device comprising a drill bit assembly, a drive shoe arranged to house the drill bit, a core sampling tube and a retraction tube. The drill bit assembly includes a bit housing, which is drivingly engaged by the drive shoe, and a series of drill segments which are pivotally attached to the housing to be capable of pivoting between a drilling position and a retracted position. The segments are maintained in the drilling position by the core sampling tube when this is in a forward position, but are allowed to adopt the retracted position when the sampling tube is withdrawn. The core sampling tube engages the drill bit assembly via the retraction tube whereby continued withdrawal of the core sampling tube causes withdrawal of the drill bit assembly from within the drive shoe.

Abstract: A hole groover comprising a pair of grooving bits radially protruding from the surface of a drill rod and connected to swivel upwardly and downwardly near the end of the drill rod where the drill bit is connected. A connecting rod is connected to the inside ends of the groove bits and causes arcuate movement of the grooving bits as it reciprocates. The hole groover further includes a gear box which is connectable to a rotary drilling unit which converts rotational movement of the rotary drill until to reciprocating movement of a lever. The lever is connected to the connecting rod which causes movement of the grooving bits. The device is readily adaptable to be connected to most rotary drill units and the depth and intervals of the grooves can be easily controlled by adjusting the length of the grooving bits and the gear ratios. The device enables grooves to be cut in a wall hole surface, concurrently with the drilling of the hole.

Abstract: Retractable core drill bit having a hollow cylindrical body at its lower end to which a monolith core drill bit is screwed. A stop sleeve is provided on the upper end of the hollow cylindrical body, and cutting components are pivotally mounted in the middle of the body. There is a spacer in the body having an end piece on its upper end around which there is driven a guiding sleeve resting on a stop sleeve which is surrounded by a outer end piece and an outer tube. There are longitudinal slots in the body for the radial movement of the cutting components which are disposed opposite to each other in interperpendicular planes.

Abstract: A boring apparatus comprises a drill pipe for being placed underground, an outer tube insertable into the drill pipe, and an inner tube axially movably inserted in the outer tube. The inner tube is locked against relative movement with respect to the drill pipe while being allowed to rotate therewith when locking members mounted on the inner tube partly project through locking member control windows in the outer tube into recesses defined in an inner surface of the drill pipe. An inner cutter and outer cutters mounted on a lower end of the inner tube can project beyond a lower end of the drill pipe, with the lowermost ends of the outer cutters being held in a projecting position radially outwardly of a circumferential surface of the drill pipe. When so positioned, the outer cutters are disposed more underground i.e., axially further away from the lower end of the drill pipe, than the inner cutter.

Abstract: A retractable well drilling bit comprises a hollow body which forms the lowermost end of the drilling string; a pair of colinear cylindrical hollow members slidable within the bore of said hollow body; a pair of knives; a vertical rod attached to the lower one of said cylindrical members and slidable within the upper one of said cylindrical members between a knife-retracted and a knife-extended position, said knives being pivotally engaged to the lower end of said rod; and a pair of crossed links pivotally attached to said upper body at the upper ends thereof and to each knife at the lower ends thereof respectively, such that by spacing said upper member from said lower member, said links will pull said knives rotating same in a knife-retracting direction, whereas when said members are approached to each other, said knives will be pushed by said links in a knife-extending position.

Abstract: A retractable bit system that includes a single piece annular core bit that is movable through a drill string (drill stem), had an outer diameter about the same as that of the drill stem, and can be releasably locked to the drill string, an outer barrel assembly for the drill stem that is operable for lockingly engaging the core bit and driving the core bit, bit replacement tools for moving and core bit through the drill string and operable for operating the outer barrel assembly and replacing the bit on the drill string without removing the drill string from a drill hole, a manually operated surface tool removably mounted on the drill string for clampingly engaging a wire line and retracting the wire line to operate the respective one of the bit installation tool and bit retraction tool when the respective tool extends into the outer barrel assembly, and a safety release tool for operating and withdrawing the replacement tools which will uncouple from the replacement tool when more than a predetermined force

Abstract: A means and method of drilling wells wherein the casing and tubing string are rotated with minimum interruption and are moved downwardly simultaneously. A bit assembly, capable of cutting a bore larger than the casing, is lowered and raised through the drill string, the bit assembly being pivotable between a position in which the transverse axis is in alignment with the drill string bore for movement therein and a drilling position in which its longitudinal axis is transverse to the axis of the drill string and surrounding casing and extends radially beyond the casing for drilling operation; the lower end of the drill string and bit assembly having interlocking parts to transmit rotational force from the drill string to the bit assembly.