Abstract: A rotary drill bit for rock drilling comprising a plurality of cutting elements mounted by interference-fit in recesses in the crown of the drill bit. Each cutting element comprises an elongated pin with a thin layer of polycrystalline diamond bonded to the free end of the pin.

Abstract: A raise drill for enlarging a pilot hole into a larger diameter hole by disintegrating the earth formations surrounding the pilot hole is disclosed. The raise drill includes a main bit body having a plurality of cutters mounted thereon. The bit body is detachably secured to the drive stem to permit removal and replacement of the stem. The removable drive stem allows the raise bit to be transported through small drifts and helps extend the useful life of the raise bit. The drive stem extends through a central opening in the raise bit body and includes an upwardly facing shoulder for engaging the margin of the bit body about the opening. The drive stem further includes a plurality of tapered flat surfaces located about the periphery of the bottom end thereof. A plurality of bolted wedge blocks, attachable to the main bit body are provided to engage the tapered flat surfaces of the drive stem in order to urge the shoulder of the drive stem into locking engagement with the main bit body.

Abstract: Apparatus and method for drilling generally horizontal holes through subterranean coal beds for release of methane gas from the coal beds are described. A sliding stabilizer on a drill rod is selectively positioned to provide elevational control to a rotating drill bit. The stabilizer is keyed to a slot in the drill rod, and lateral offsets in the slot are used to retain the stabilizer in the desired position on the drill rod.

Abstract: A rotary air percussion drill bit which has a cylindrical body portion with first and second ends. A flat bottom face comprises one end with a shaft attached to the remaining end. A plurality of hard inserts is mounted in the body portion and projects downwardly from both the body portion and from the flat bottom face. The rotary air percussion drill bit has a first chip clearance means formed into the body portion longitudinally along its side wall with a second chip clearance formed around the side wall intermediate the first and second ends. The improvement in the rotary air percussion drill bit provides for a vertical slot which cuts through the drill base down the drill body and forms an arcuate terminus tapered to the cylindrical wall to the drill bit. A gauge tooth is mounted in the arcuate terminus at approximately 20.degree. to 35.degree. with a line normal to the axis of the drill bit.

Abstract: A hydromechanical drilling tool which combines a high pressure water jet drill with a conventional roller cone type of drilling bit. The high pressure jet serves as a tap drill for cutting a relatively small diameter hole in advance of the conventional bit. Auxiliary laterally projecting jets also serve to partially cut rock and to remove debris from in front of the bit teeth thereby reducing significantly the thrust loading for driving the bit.

Abstract: A method for inhibiting the wear in a well casing is accomplished by determining the depths within a bore hole of a well where a drill string may contact the well casing. The casing is then run into the bore hole with one or more hardened wear sections positioned therein for ultimate landing at the depths where the drill string may contact the casing.

Abstract: A borehole drilling apparatus adapted for connection to a drilling string, wherein the cuttings pass through the center of the drill bit and are adapted for conveyance to the surface through a central pipe of the drilling string, a labyrinth seal being located between the outer perimeter of the apparatus and the wall of the borehole to provide an annular region of relatively immobile or stagnant fluid around the apparatus to forestall movement of fluid upwardly and downwardly past the labyrinth seal, part of the drilling fluid being conducted in a downward direction below the seal to force cuttings toward and through the center of the drill bit for upward conveyance through the central pipe, another portion of the drilling fluid being discharged above the seal for upward conveyance through the annulus between the drilling string and wall of the borehole to the top of the latter, whereby any formation material which may drop into the borehole annulus will be forced upwardly through such annulus to the top of t

Abstract: A boring device adapted for deep well drilling wherein a cutting plate is fixed in operative position in a recess of a boring head by means of a clamping bolt. The cutting plate is reversible and its position in the boring head is adapted to be adjusted in a substantially radial direction. The cutting plate has a serrated surface and the bottom of the recess has a matingly serrated surface which when contacting each other enhance the clamping action of the clamping bolt.

Abstract: There is disclosed a single wire multiple shot selective fire perforating gun for piercing oil field tubular goods, typically during the process of completing an oil or gas well. A switch in the gun electrically isolates an associated blasting cap and short circuits the terminals thereof until the associated blasting cap and perforating element are armed. A plurality of blasting cap perforating element assemblage are vertically disposed on the tool with the detonation of one perforating element arming the next adjacent blasting cap.

Abstract: A pneumatic percussion boring device, which is particularly intended for boring tunnel-like holes in the ground, comprises a percussion boring tool which is mounted in a tubular housing, a percussion piston which, in operation, reciprocates in the housing and acts on the tool, and a displacement piece which is mounted on the boring tool for laterally displacing the soil through which the boring is being made. The displacement piece tapers in the direction of boring and is formed around its periphery with a series of annular cutting edges. The displacement piece is preferably stepped with each step being of an increasing diameter in a rearward direction with one of the cutting edges extending around the outer periphery of each step. The forwardly directed face of each step may be undercut with a concave annular depression which increases the sharpness of the cutting edge at the outside of the step.

Abstract: A self-propelled pnuematic burrowing device having an axially reciprocating percussion plunger arranged inside a tubular casing so as to strike a percussion head at the forward extremity of the casing, thereby advancing the device through the ground by crushing and/or displacing the material in the path of the device, the percussion head being freely displaceable between axial abutments defined by a guide sleeve of the casing, the displaceability being slightly in excess of the advance of the device per stroke and adjustable through the insertion and removal of split spacer rings. The air controls of the device, located in the rear portion of the casing, include a control barrel with an enlarged control head and a gradually widening central air supply channel.

Abstract: A drill cuttings and dust control hood formed as an inverted rectangular box having depending flexible skirts on three lateral sides and a swinging door formed on a fourth side of the box for drill cuttings removal. The dust control hood includes a conical drill cuttings deflector disposed around the drill stem and directly above the drill hole. The conical deflector includes a plurality of apertures disposed around its base and above a transverse baffle plate. A source of air suction is connected to a tangential outlet opening through the deck of the hood into the interior of the space formed within the conical deflector. Flexible collars on the hood deck and the apex of the conical deflector form dust seals around the drill stem.

Abstract: In an offshore oil well system wherein a floating well platform is connected through a telescoping cylindrical member to a marine riser extending down to the drilling area, the telescoping cylindrical member being mounted for slidable, sealable movement within the top of the marine riser, said movement occurring as a result of heave of the floating platform due to wave and tide action, a drilling fluid compensator for compensating for a change in the flow of drilling fluid out of the telescoping cylindrical member into the return system.

Abstract: A flame jet tool for drilling a hole in the ground at great depths is disclosed. The tool comprises a flame jet lance having a drill bit and an associated fuel system. The lance is disposed in a guide sheath such that the lance may be raised and lowered therefrom. The tool may also include means for capturing debris. In operating the flame jet tool of the present invention, the guide sheath is lowered into a preexisting well hole a specific distance. The guide sheath is fixed to the sides of the hole and the flame jet lance is lowered from the guide sheath. At a predetermined point, the drill bit is ignited and caused to rotate thus increasing the depth of the hole. By the use of the flame jet tool of the present invention, holes of significant depth can be increased and materials of extraordinary hardness can be pierced.

Abstract: A roof drilling system which includes a drill bit with a hollow driven shank and coolant holes in the bit flutes connected to the inside of the hollow shank, a single driver unit connectible to the drill bit and also to extension driver elements which interfit with both the bit and the driver, all of the elements being hollow and connected by retainers which secure the parts during the drilling and aid in the withdrawal from the drilled hole.

Abstract: A marine riser, which is hung from a drilling platform floating on a body of water and connected at its lower end to a wellhead, is buoyantly tensioned by one or more float cans with open bottoms. These float cans are connected at their upper end to the riser to which air under pressure is controllably supplied. The pressurized air blows out the water in each can to achieve the desired buoyancy. The float can may having an air dump valve interconnected with similar valves in the other cans. The function of these valves is to release the pressurized air in the can if the riser parts. At the upper end of the riser is a slip joint, which may include safety water-dampening gear to further reduce upward motion of a parted riser. The optional dampening gear comprises an annular piston formed by the upper section of the slip joint that forces water through ports in the exterior of the lower section of the slip joint as the riser below the slip joint moves upward.

Abstract: An improved offshore drilling method and apparatus are disclosed which are useful in preventing formation fracture caused by excessive hydrostatic pressure in a drilling riser. Gas is injected into the riser to provide the lift necessary to return the drilling fluid to the surface and to reduce the density of the drilling fluid. The rate of gas injection overlifts the drilling fluid to the extent that the pressure of the fluid is reduced to less than that of the seawater surrounding the riser. Seawater is permitted to flow into the lower end of the riser in response to the differential pressure between the drilling fluid and seawater so that the pressures of the drilling fluid and the seawater approximately equalize.

Abstract: A rotary rock drill bit comprising a plurality of cutting elements or cutters mounted in the crown of the drill bit. Each cutting element comprises a thin planar layer of polycrystalline diamond bonded in the crown of the bit at a rake angle of between -10.degree. and -25.degree.. In another embodiment each cutting element comprises an elongated pin mounted at one end in the drill crown and thin layer of polycrystalline diamond bonded to the free end of the pin so as to be disposed at a rake angle of between -10.degree. and -25.degree..

Abstract: In raise bore drilling, a drill string of non-round cross-sectional configuration is connected through a pilot hole from a raise bore bit at the lower end of the pilot hole to a raise bore drilling rig at the upper end of the hole. The drill string is defined by a number of serially connected individual pipe lengths. The drill string configuration preferably is hexagonal except at one end of each length where the pipe length is round for a distance which corresponds to the length of a female threaded connection component defined by that end of the pipe length. The other end of each pipe length defines a cooperating male threaded connection component.

Abstract: A reentry system for a subsea apparatus or station including a normally retracted guide post, which is extendable above the well apparatus for connection to a single guide line. A frame structure lowered along the single guide line includes a gimbal mounted guide funnel assembly which provides self-adjustment of the funnel assembly during a non-axial approach into axial alignment with the guide post means. The guide posts means and funnel assembly are provided with orientation and positioning means for the frame structure so that well equipment carried by the frame structure is positioned in alignment with its cooperable part on the well apparatus. A retractable, extendable guide post which is non-rotatable and which is recoverable for maintenance and service. A method of making such a reentry to a subsea well apparatus.