Abstract: A valve includes an exterior body and an interior body. The exterior body includes an ultrahard material, at least one exterior inlet, at least one exterior outlet, and a chamber inside the exterior body and in fluid communication with the exterior inlet and the exterior outlet. The interior body is located in the chamber within the exterior body and is moveable relative to the exterior body from an open configuration to a closed configuration. The interior body includes an ultrahard material, at least one interior inlet, and at least one interior outlet.

Abstract: A valve includes an exterior body and an interior body. The exterior body includes an ultrahard material, at least one exterior inlet, at least one exterior outlet, and a chamber inside the exterior body and in fluid communication with the exterior inlet and the exterior outlet. The interior body is located in the chamber within the exterior body and is moveable relative to the exterior body from an open configuration to a closed configuration. The interior body includes an ultrahard material, at least one interior inlet, and at least one interior outlet.

Abstract: Interfacing surfaces of adjacent tiles in a downhole tool may combine to form a tortuous path therebetween. In various embodiments, this tortuous path may run generally parallel and/or perpendicular to a top surface of the tiles. One example of such a tortuous path may be created by a protrusion extending from an interfacing surface of one of the tiles that may fit snugly within a cavity receding into an interfacing surface of another of the tiles.

Abstract: A system includes a turbine, a valve, and an electronics package. The turbine is configured to generate electricity from a fluid flow through the turbine and the electronics package is configured to selectively actuate the valve between an open configuration and a closed configuration.

Abstract: A system includes a turbine, a valve, and an electronics package. The turbine is configured to generate electricity from a fluid flow through the turbine and the electronics package is configured to selectively actuate the valve between an open configuration and a closed configuration.

Abstract: A rotary drill bit for use in drilling holes in subsurface formations comprises a bit body having a leading face and a gauge region, a number of blades formed on the leading face of the bit and extending outwardly away from the axis of the bit so as to define between the blades a number of fluid channels leading towards the gauge region, a number of cutting elements mounted side-by-side along each blade, and a number of nozzles in the bit body for supplying drilling fluid to the fluid channels for cleaning and cooling the cutting elements. In each of the fluid channels, adjacent the gauge region, is an opening into an enclosed passage which passes internally through the bit body to an outlet which, in use, communicates with the annulus between the drill string and the wall of the borehole being drilled. The gauge region of the drill bit comprises a substantially continuous bearing surface which extends around the whole of the gauge region.

Abstract: A rotary drill bit for use in drilling holes in subsurface formations comprises a bit body having a leading face and a gauge region, a number of blades formed on the leading face of the bit and extending outwardly away from the axis of the bit so as to define between the blades a number of fluid channels leading towards the gauge region, a number of cutting elements mounted side-by-side along each blade, and a number of nozzles in the bit body for supplying drilling fluid to the fluid channels for cleaning and cooling the cutting elements. In each of the fluid channels, adjacent the gauge region, is an opening into an enclosed passage which passes internally through the bit body to an outlet which, in use, communicates with the annulus between the drill string and the wall of the borehole being drilled. The gauge region of the drill bit comprises a substantially continuous bearing surface which extends around the whole of the gauge region.

Abstract: A rotary drill bit for use in drilling holes in subsurface formations comprises a bit body having a leading face and a gauge region, a number of blades formed on the leading face of the bit and extending outwardly away from the axis of the bit so as to define between the blades a number of fluid channels leading towards the gauge region, a number of cutting elements mounted side-by-side along each blade, and a number of nozzles in the bit body for supplying drilling fluid to the fluid channels for cleaning and cooling the cutting elements. In each of the fluid channels, adjacent the gauge region, is an opening into an enclosed passage which passes internally through the bit body to an outlet which, in use, communicates with the annulus between the drill string and the wall of the borehole being drilled. The gauge region of the drill bit comprises a substantially continuous bearing surface which extends around the whole of the gauge region.

Abstract: A rotary drill bit for use in drilling holes in subsurface formations comprises a bit body having a leading face and a gauge region, a number of blades formed on the leading face of the bit and extending outwardly away from the axis of the bit so as to define between the blades a number of fluid channels leading towards the gauge region, a number of cutting elements mounted side-by-side along each blade, and a number of nozzles in the bit body for supplying drilling fluid to the fluid channels for cleaning and cooling the cutting elements. In each of the fluid channels, adjacent the gauge region, is an opening into an enclosed passage which passes internally through the bit body to an outlet which, in use, communicates with the annulus between the drill string and the wall of the borehole being drilled. The gauge region of the drill bit comprises a substantially continuous bearing surface which extends around the whole of the gauge region.

Abstract: A cutter assembly for a rotary drag-type drill bit includes a preform cutting element comprising a front facing table of polycrystalline diamond bonded to a tungsten carbide substrate, the cutting element being mounted on a tungsten carbide carrier which is received in a socket in the body of the drill bit. The carrier comprises a sector-shaped portion of a disc, and the cutting element is bonded to one of the straight edge surfaces of the carrier, adjacent the apex of the sector shape. The side surfaces of the carrier taper inwardly, as viewed in cross-section, as they extend towards the curved edge surface of the carrier.

Abstract: A rotary drill bit for use in drilling holes in subsurface formations comprises a bit body having a leading face and a gauge region, a number of blades formed on the leading face of the bit and extending outwardly away from the axis of the bit so as to define between the blades a number of fluid channels leading towards the gauge region, a number of cutting elements mounted side-by-side along each blade, and a number of nozzles in the bit body for supplying drilling fluid to the fluid channels for cleaning and cooling the cutting elements. In at least one of the fluid channels, adjacent the gauge region, is an opening into an enclosed passage which passes internally through the bit body to an outlet which, in use, communicates with the annulus between the drill string and the wall of the borehole being drilled. The portion of the gauge region outwardly of the opening comprises a bearing surface which, in use bears against the wall of the bore hole and extends across the width of the channel.

Abstract: A rotary drill bit for drilling holes in subsurface formations comprises a bit body having a shank for connection to a drill string, a number of circumferentially spaced blades on the bit body each extending outwardly away from the central axis of rotation of the bit, a number of cutters mounted side-by-side along each blade, and a passage in the bit body for supplying drilling fluid to the surface of the bit for cleaning and cooling the cutters. The blades comprise alternating primary and secondary blades. The cutters on the primary blades are primary cutters which are located at different radial distances from the bit axis so as to define a cutting profile which, in use, covers substantially the whole of the bottom of the bore hole being drilled. At least the majority of the cutters on the secondary blades are secondary cutters each of which is located at substantially the same radial distance from the bit axis as an associated primary cutter on the preceding primary blade.

Abstract: A rotary drill bit comprises a bit body having a shank for connection to a drill string, a plurality of cutter assemblies mounted on the bit body, and a passage in the bit body for supplying drilling fluid to the surface of the bit. Certain cutter assemblies on the bit body are adapted to exhibit a volume factor which is significantly greater than the volume factor of other cutter assemblies on the bit body, with increase of rate of penetration, and at least the majority of said cutter assemblies of higher volume factor are better adapted for cutting softer formations than at least the majority of said other cutter assemblies. The bit therefore tends to act as a "heavy set" drill bit at lower rates of penetration in hard formations, and as a "light set" drill bit at higher rates of penetration in softer formations, and therefore tends to drill each formation more efficiently.

Abstract: A cutter assembly for a rotary drill bit comprises an elongate stud to be received in a socket in the surface of the bit body, the stud having mounted at one end thereof a preform cutting element. At least a major part of the stud is generally in the form of a cylinder of a circular cross-section having two symmetrically disposed flats extending longitudinally thereof, the flats being inclined towards the longitudinal axis of the stud as they extend towards the end of the stud remote from the cutting element. The flats allow the cutter assemblies to be packed together more closely side-by-side across a convexly curved surface of the body of the drill bit.

Abstract: A rotary drill bit comprises a bit body having a shank for connection to a drill string and a passage for supplying drilling fluid to the face of the bit, which carries a plurality of polycrystalline diamond preform cutting elements. The cutting elements on one side of a diameter of the bit have positive side rake and the cutting elements on the other side of the diameter have negative side rake so that the vectorial sum of the reaction forces between the formation being drilled and the cutting elements provides a resultant lateral imbalance force acting on the bit body as it rotates in use. The gauge of the bit body includes low friction bearing pads so located as to transmit the resultant lateral force to the sides of the borehole. Since the bearing pads are of low friction, they slide around the surface of the formation and any tendency for bit whirl to be initiated is reduced.

Abstract: A preform cutting element, for a rotary drill bit, includes a layer of polycrystalline diamond material having a front cutting face, a rear face and a peripheral surface, a cutting edge being provided by at least part of the junction between the front cutting face and the peripheral surface. The diamond layer is formed around its periphery, adjacent the cutting edge, with a row of spaced apertures. Each aperture is in the form of a bore, formed for example by a laser, which is inclined at 45.degree. to the cutting face and extends completely through the diamond layer from the cutting face to the peripheral surface thereof. The apertures serve to inhibit the propagation of spalling across the cutting face from the cutting edge.

Abstract: There is provided a method of manufacturing a rotary drill bit of the kind including a plurality of cutting structures mounted in sockets in the bit body and projecting from the face of the bit. The method comprises providing a clearance between each cutting structure and its socket and filling the clearance with a settable liquid, the settable liquid being such as to solidify at a temperature less than 400.degree. C. and to retain its integrity, after solidification, at least up to a temperature of 180.degree. C. The solidified liquid acts as a gap filler and provides an interference fit between the cutting structure and the socket. Suitable gap filing settable liquids are: anaerobic adhesive, epoxy resin, dental amalgam, tin/lead solder and bismuth/antimony alloy.

Abstract: An elongate cutter for a drag-type drill bit includes a stud defining one end thereof and a cutting formation comprising a cutting face generally adjacent the other end. Length extends from one end to the other, depth extends generally transverse to the cutting face as well as transverse to the length, and width extends transverse to both length and depth. The stud has a cross section transverse to its length such that the cross section cannot be circumscribed by a reference circle whose diameter is equal to the maximum width of the cross section. The cross section also has an assumed section modulus, in the direction of depth, greater than that of the reference circle. The leading side of the cutter comprises a first planar zone adjacent the one end and a second planar zone adjacent the other end, and on which the cutting formation is carried. The maximum lateral dimension of the leading side is generally greater than or equal to the maximum width of the cutter.

Abstract: A rotary drill bit comprises a bit body having a leading face and a gauge region, a number of blades on the leading face of the bit body, and a number of cutting elements mounted along each blade. A passage in the bit body supplies drilling fluid to nozzles in the leading face of the bit body for cooling and cleaning the cutting elements. Each nozzle is so oriented, and the surface of the bit body in the region in front of each blade is so shaped, as to promote a vortex flow of drilling fluid around said region, with part of the periphery of the vortex extending across the cutting elements on the blade, so that fluid in the periphery of the vortex passes across the cutting elements mounted on each blade before escaping through an exit channel in the gauge region.

Abstract: A rotary drill bit for use in drilling deep holes in subsurface formations comprises a bit body having a leading face and a gauge region, a plurality of cutting elements mounted at the surface of the leading face of the bit body, a passage in the bit body for supplying drilling fluid to a plurality of openings in the leading face of the bit body, and one or more junk slots in the gauge region of the bit body, whereby drilling fluid emerging from the openings flow over the leading face of the bit body and past the cutting elements thereon, so as to cool and clean the cutting elements before exiting through the junk slot.