Abstract: A method of monitoring the wear of drill bits for drilling wells in earth formations, several embodiments of an improved drill bit for drilling a well in an earth formation, and methods of manufacture. In one embodiment, the bit is assembled by forming the bit, including a bit body and a plurality of cutting components; introducing a wear detector into the bit; and providing a module to monitor the wear detector and generate an indication of bit wear. The wear detector may be one or more electrical circuits that may experience a change in resistance or conductivity due to wear of the bit. The module may determine wear by detecting an open circuit. The wear detector may be introduced during or after formation of the bit. The bit wear may be displayed for an operator.

Abstract: A device for driving boreholes in the ground, having a rotationally driven main shaft with a shaft journal whose axis (B) forms an acute angle with respect to the axis (A) of the main shaft. A drill head is mounted such that it can rotate about the axis (B) of the shaft journal and has a circumferential region which runs on a complementary circumferential region, wherein the complementary circumferential region can be set rotating.

Abstract: The invention relates to a device for drilling a bore in the ground, comprising a drive system with a connecting rod assembly that extends from the drive system into the ground. The end of said assembly pointing towards the face or base of the bore is connected to a tool head (40). The device also comprises several tools (41) that are located on the tool head (40) and work on the face or the base of the bore. The inventive device is characterised in that each tool (41) comprises an excavation disc (45) and elements that cause the excavation disc (45) to oscillate during operation.

Abstract: A lubricating nutating single cone drill bit 10 includes bit shank 12 with an axially skewed journal 18 rotatably retaining cutter body 22. Bearings (26, 28, 30, 32) enable rotation of the cutter body 22. Lubrication flows to a gap between the axially skewed journal 18 and cutter body 22 from lubricant chamber 76 having plunger 80 acted on by an annulus fluid, the gap bounded by first 66 and second 68 radial dynamic seals. A fluid passage 90 extending through the bit 10 communicates with fluid inlet port 88 on the proximal end 16 of the bit shank 12. Fluid passage 90 also communicates with a first fluid outlet port 98 on the distal end 36 of the axially skewed journal 18 and with a second fluid outlet port 94 formed on a lateral portion of bit shank 12.

Abstract: A lubricating nutating single cone drill bit 10 is disclosed. Bit 10 includes a bit shank 12 with an axially skewed bore 18 rotatably retaining a cutter body 22. A plurality of cutter elements (46, 48) are affixed to the cutter body 22. Bearings (26, 28, 30, 32) enable rotation of the cutter body 22 and lubricant is dispensed to the bearings from a lubricant chamber (76, 76?) by a plunger 80 driven by drilling fluid. A method to drill includes attaching the bit 10 to a drill string, engaging the bit 10 into a formation (WB), pumping a drilling fluid into a plunger 80 in the lubricant chamber 76 to dispense lubricant to the bearings (26, 28, 30, 32). The method can include pumping the drilling fluid through a fluid passage 90 in the bit 10 and out of a low pressure orifice 94 on the cutter body 22.

Abstract: A roller cone drill bit includes a bit body adapted to be coupled to a drill string, a bearing journal depending from the bit body, and a single roller cone rotatably attached to the bearing journal. The single roller cone has a plurality of cutting elements, where at least one of the plurality of cutting elements is formed of an inner region that is at least partially surrounded by an outer region, where the inner region is more abrasive resistant than the outer region. Such an arrangement in a single roller cone bit allows the at least one cutting element to be “self-sharpening.

Abstract: A nutating single cone drill bit includes a bit shank defining a bit axis, a journal defining a rotation axis skewed from the bit axis, and a cutter elements mounted upon a cutter body wherein the tip of each cutter elements is forward a plane defined normal to the cutter axis at an intersection of the cutter axis with the bit axis.

Abstract: The present invention includes a nutating single cone drill bit which rolls and crushes the bore face without dragging cutters which are not directly engaging the borehole thereby reducing wear and torque on the drill string, and which because of the large thrust bearings can withstand large compressive loading of the drill string assembly on the bit.

Abstract: A drill bit including a roller cone and fixed cutters positioned external to the roller cone and radially from the bit axis of rotation. The roller cone is located so that a drill diameter of the cone is substantially concentric with an axis of rotation of the bit. The fixed cutters can be made of tungsten carbide, polycrystalline diamond, boron nitride, or any other superhard material. The fixed cutters are positioned to either maintain the hole diameter drilled by the roller cone or to drill a larger diameter hole than the hole drilled by the roller cone. The single roller cone may be located in the center of a multi-cone bit arrangement or in the center of a PDC bit to assist in drilling the center of a wellbore. The single roller cone may be used to form a bi-center bit in combination with a reaming section. The single roller cone may also be located on an independent sub that is removably attached to the bit body.

Abstract: A drill bit is fictionally received over a drill rod via complementary generally frusto-conical male formation and socket. The socket has an inwardly protruding face at an angle with the longitudinal axis of the drill rod. The male formation on the drill rod has a depression in the form of an area where the convexity of the frusto-conical portion has been flattened at an angle so as to form a rocking formation at a selective location relative to the opposite ends of the male formation and the socket. A clearance space diverges away from the rocking formation toward a selective ends of the male formation and the socket. The frusto-conical male formation and the socket are a-circular and form positive driving engagement between the drill rod and the drill bit. An impact at the point of maximum clearance causes rocking about the rocking formation to break static friction and to facilitate release of the drill bit from the drill rod.

Abstract: A drill bit for drilling subterranean formations includes a device to provide a "universal" effect between the shank and crown for self alignment of the crown with the bore hole in the formation. The bit is suitable for downhole assemblies configured for straight drilling, directional drilling and navigational drilling. The device can be incorporated into both drag bits and roller-type "rock" bits. Preferred embodiments include a flexible sub connecting the crown to the shank portion and having reduced stiffness relative to the drill string. Alternatively, a spherical universal joint or trunnion type universal is used. Replaceable lugs increase durability and reliability of the universal. The device equalizes the loads on cutters while reducing wear, average loads, and impact loads on cutters. Bore hole diameter and chatter of the bit in the bore hole are reduced, promoting maximum efficiency and rate of penetration as wobble and precession are minimized.

Abstract: A drill bit for drilling subterranean formations includes a device to provide a "universal" effect between the shank and crown for self alignment of the crown with the bore hole in the formation. The bit is suitable for downhole assemblies configured for straight drilling, directional drilling and navigational drilling. The device can be incorporated into both drag bits and roller-type "rock" bits. Preferred embodiments include a flexible sub connecting the crown to the shank portion and having reduced stiffness relative to the drill string. Alternatively a spherical universal joint or trunnion type universal is used. Replaceable lugs increase durability and reliability of the universal. The device equalizes the loads on cutters while reducing wear, average loads, and impact loads on cutters. Bore hole diameter and chatter of the bit in the bore hole are reduced, promoting maximum efficiency and rate of penetration as wobble and precession are minimized.

Abstract: A rock-cutting tool includes a sleeve equipped with cutting elements and supported on a shaft, the sleeve being separately rotatable and eccentrically arranged in relation to the shaft whereby, in use, rotation of the shaft imparts a radially oscillating motion on the sleeve. At least one adjustable counterweight is connected to the shaft and located within the sleeve.

Abstract: A drill bit for earth boring purposes includes a drill bit body which is rotatable about a drilling axis, a single cutting member mounted rotatably on the body and a counter-reaction member also mounted on the body. The counter-reaction member extends partially downwardly from the body and includes first and second outwardly exposed surfaces. The first surface has a greater surface area than the second surface and is at least partially formed with a circumferentially disposed curvature and a longitudinally disposed curvature with respect to the drilling axis so that it can closely conform to and contact the curvature of the bottom of the hole formed by the drill bit. The first surface of the counter-reaction member acts as a friction pad to counteract the torque effects of rotating the drill bit about the drilling axis and the cutting member engaging in the ground.

Abstract: The invention relates to a drill bit which includes a drive arrangement having two opposed drive shafts which are transverse to the drill rod axis, mechanism for driving the shafts and a rock comminuting cutter which is eccentrically mounted on each of the shafts.

Abstract: A rock cutting assembly which includes a rock cutting roller with the roller being composed of a central hub portion and an annular cutting element which is rotatably mounted on the hub and carries rock cutting formations, means for driving the hub portion of the roller about an axis which is eccentrically displaced from the hub axis, means engaged with the annular cutting element to limit its direction of rotation relatively to that of its hub to one direction only and means for balancing the roller against its eccentricity as the hub is rotated about its drive axis. Preferably the assembly includes a plurality of rock cutting rollers which are rotatable about a common drive axis with the axes of each roller hub being eccentrically displaced by a common distance and in such a direction from the drive axis so that the rollers balance each other as the rollers are rotated about their drive axis.

Abstract: Method and apparatus for drilling a straight borehole in all types of geological formations by the provision of a drilling tool that maintains a constant hole angle respective to the vertical as the borehole is formed. The apparatus includes a bit to which there is rotatably secured a plurality of cones. The cones are mounted to a cutterhead, with the cutterhead being attached to the lower marginal end of a shank. The cutterhead is placed at an incline respective to the shank whereby a plane passing through the cones of the bit lies obliquely respective to the axial centerline of the shank. When the bit weight is applied, the oblique angle between the cones and the shank causes the drill string weight to be transferred unevenly to the cones, whereupon a significant radial force is effected on each of the individual cones.

Abstract: In a drill bit comprising a body having a channel therethrough for carrying drilling fluid for injection into a bore hole through a nozzle at one end thereof and a cutting head mounted in the body and contacting the bottom of the bore hole. The improvement comprises at least one passage extending from the channel to a side portion of the exterior surface of the body wherein drilling fluid in the channel will flow through the at least one passage to the exterior of the body and form a fluid layer between the side portion of the body and the opposing side of the bore hole.

Abstract: A rotary drill bit has an upper rotatable main body member which rotates respective to a lower stationary bit member. The lower stationary bit member has an axial centerline arranged at an angle respective to the axial centerline of the upper body member. The lower face of the lower bit member terminates in a formation engaging surface which is in the form of a cone so that as the drill string imparts rotation into the main body member, the face of the lower member engages the formation and is wobbled by the action of the rotating main body. This action forces a limited area along one side of the conical face to bear against the formation. The formation engaging portion of the bit face travels circumferentially about the bit due to the eccentricity or misalignment of the two bit members. The wobble action imparts great pressure on the bottom of the borehole, increases penetration of the bit, and reduces wear on the cutting elements of the bit face.

Abstract: A Zublin type rotary drill bit is disclosed having a main body rotating about a main axis. The bit body includes a journl pin extending downwardly therefrom, with the journal pin forming a second axis disposed at an angle with respect to the main axis. The journal pin has a cutter rotatively mounted thereon, with the cutter having a spherical outer surface which has a plurality of inner rows of tungsten carbide mounted thereon. The gage row of the cutter is also formed on the spherical outer surface and defines a plane intersecting the intersection of the main and second axes. The cutter gage row is formed by a plurality of inserts having synthetic diamond cutting surfaces, which are facing downwardly toward the apex of the cutter, in order to scrape the sides of the bore hole during the downwardly traveling portion of the gage insert travel cycle.

Abstract: A nutating earth drilling bit which is adapted for use in drilling systems in which the drilling fluid and cuttings are transported from bit to surface through the interior of the drill string. The nutating bit is provided with a toroidal cutting member and a longitudinally extending annular shank, both of which have longitudinally extending passageways aligned with one another and in flow communication with the central return conduit of the drill string. The cutting member of one embodiment has a segmented cutting web at its lower end which divides the central passageway into three separate fluid return channels. Another embodiment drills an annular hole face around an uncut earth core, the core being permitted to rise into the shank member where it is broken into short segments by a core breaker.

Abstract: A partially solid head bit having a flow passage therethrough located at approximately the center of the bit is shown. The bit is designed for use in conjunction with a hammer action drilling apparatus. The flow passage extends through a shank of the bit to the bottom thereof. Surrounding the shank is a substantially hemispherical spiraled burr having an opening therethrough. The burr pushes against a shoulder of the shank during drilling. The mating surfaces of the shank and burr are lubricated by a suitable oil reservoir. On spirals of the burr and on the lower end of the shank are mounted hardened inserts for impacting against and breaking up the formation through which the bit may drill. The bottom of the shank may be even with, extend through, or be recessed with respect to the lower edge of the burr. The shank is angled a few degrees off the centerline of the drilling string to cause a wobbling action upon rotating the drill bit.