Abstract: Disclosed is a method of comparing the relative lateral stability among drill bits (that is, the tendency for a bit to whirl). This allows improved bit selection in applications where whirl is apparent. Because there will likely be many different acceptable bit designs produced by the above method, the comparison of the regenerative forces among these bits allows a customer to make a more informed choice between stability and other performance features among a range of bit designs.

Abstract: This invention provides an asynchronous electronic circuit that has an asynchronous memory circuit where the memory cells are arranged in columns and rows. The asynchronous circuit includes a read completion detection circuit and a write completion detection circuit that determines an end of the read cycle or the write cycle for a word byte of information. Upon completion of the read or write cycle an acknowledge signal is generated from the read completion detection circuit or the write completion detection circuit. The read and/or write acknowledge signal is used as a control signal to advance the electronic circuit to the next subsequent step in a process. The invention further provides a method for detecting the end of a read and/or write cycle issuing an acknowledge signal that may be used to provide control to an asynchronous electronic circuit to advance to the next step in a sequence.

Abstract: A stabilizer comprises a body having first and second ends, each of which is formed with a respective connector means, the body having an outer wall upon which is formed a plurality of the upstanding blades radially outer surfaces of which define gauge pads, flow channels being defined between adjacent ones of the blades, and at least one bridging region interconnecting two adjacent ones of the blades to form an enclosed passage communicating with an associated one of the flow channels, the bridging region having a surface defining part of an outer gauge surface of the stabilizer, the at least one bridging region being located intermediate and spaced from the first and second ends.

Abstract: A tool string stab guide for axially aligning first tool string components with second tool string components is disclosed. The stab guide has a body with an axial length along a longitudinal axis with a first and a second section. The first section of the body adapted for removable attachment within a diameter of a bore of a tool string component. The second section of the body has a centering element with a flow channel. The ratio of the axial length to the diameter is at least 2:1.

Abstract: A method and system for use in synchronizing at least two clocks in a downhole network are disclosed. The method comprises determining a total signal latency between a controlling processing element and at least one downhole processing element in a downhole network and sending a synchronizing time over the downhole network to the at least one downhole processing element adjusted for the signal latency. Electronic time stamps may be used to measure latency between processing elements. A system for electrically synchronizing at least two clocks connected to a downhole network comprises a controlling processing element connected to a synchronizing clock in communication over a downhole network with at least one downhole processing element comprising at least one downhole clock. Preferably, the downhole network is integrated into a downhole tool string.

Abstract: The present invention includes a downhole component adapted for transmitting downhole data. The downhole component includes a threaded end on a downhole component. The threaded end furthermore includes an interior region, and exterior region, and a mating surface wherein a cavity is formed. A data transmission element is disposed in the cavity and displaces a volume of the cavity. At least one passageway is formed in the threaded region between interior and exterior regions. The passageway is in fluid communication with both the interior and exterior regions and thereby relieves pressure build up of thread lubricant upon tool joint make up.

Abstract: A rotary valve assembly for a rotary steerable tool is disclosed for directing flow of an abrasive laden drilling fluid; the valve assembly has a first sealing surface rotatably engaging a second sealing surface. At least one of the surfaces has at least about 5% of its area comprising interconnecting voids to an average depth of at least 0.02 mm. The interconnected voids allow fluid pressure to equalize between the sealing faces by flowing through the interconnecting voids to the sealing surfaces. Because the fit of the sealing surfaces of the valve is less than perfect, and because the voids on mating surfaces do not necessarily overlap, the 5% of the surface area comprising interconnected voids can easily translate to a 10% or more reduction in sealed area when both sealing surfaces have the interconnecting voids. The additional reduction in surface area subjected to differential pressure has substantially eliminated the hydraulic lock problem previously encountered upon startup.

Abstract: A method to design a bi-center drill bit designed to drill out the cement and other material in the casing and then proceed to drill out the full gauge drilling diameter borehole with a diameter greater than the inside of the casing. The bi-center drill bit has a pilot section on the end of the bit body, an eccentric reamer section and a plurality of cutting elements on the pilot section. The design method comprises the steps of: defining a first center of rotation of the pilot section about the longitudinal axis, defining a radius of rotation R1 of the drill bit about the first center of rotation, defining a second center of rotation of the pilot section spaced apart from the first center of rotation by a distance D, defining a radius of rotation R2 of the drill bit about the second center of rotation, and setting the relationship between D, R1 and R2 such that R1 is less than the sum of R2 and D.

Abstract: The present invention provides an earth boring drill bit with a superhard polycrystalline diamond or diamond-like element with greatly improved resistance to thermal degradation without loss of impact strength. Collectively called PCD elements, these elements are formed with a binder-catalyzing material in a high-temperature, high-pressure process. The PCD element has a plurality of partially bonded diamond or diamond-like crystals forming at least one continuous diamond matrix, and the interstices among the diamond crystals forming at least one continuous interstitial matrix containing a catalyzing material. The element has a working surface and a body, where a portion of the interstitial matrix in the body adjacent to the working surface is substantially free of the catalyzing material, and the remaining interstitial matrix contains the catalyzing material. This translates to higher wear resistance in cutting applications and has advantages in numerous other applications.

Abstract: A drill bit for drilling a borehole, the drill bit comprising a bit body 10 having an axis of rotation 12, a leading face, a plurality of blades 26 upstanding from the leading face, at least one of the blades terminating in a gauge pad 28 having a gauge surface 29 arranged, in use, to face a wall 30 of the borehole 32, the gauge surface 29 being devoid of cutting elements, the gauge surface 29 terminating at an end thereof remote from the blade at a junction 58 with a gauge pad end wall 56, wherein the gauge pad 28 carries a single cutter 62 having a face 64 and a cutting edge 65 located radially inward of the gauge surface 29, and wherein the junction 58 of the gauge surface 29 and the gauge pad end wall 56 crosses, radially, between the face 64 of the cutter 62 and the wall 30 of the borehole 32.

Abstract: The present invention relates to a method of forming a powder rod core comprising injecting a powder mix material into a mold, moving the mold to a curing station, and injecting material into a second mold.

Abstract: Disclosed is a tooth type rolling cutter earth boring drill bit with secondary cutting elements on the tooth surfaces. The secondary cutting elements provide additional, relatively sharp edges that help cut hard rock. The teeth also have convex radiused buttresses at their bases to reduce the stresses the teeth experience when drilling through extremely hard rock. This allows the tooth bit to survive the high loads encountered when drilling hard, tough rock formations, without breaking the teeth. The combination of teeth with secondary cutting elements and convex radiused buttresses at their base provide a tooth type rotary drill bit that has superior resistance to wear and breakage when drilling through hard, tough rock without significantly reducing the drilling rate of penetration when drilling through soft rock.

Abstract: The present invention is a self adjusting, volume balanced, single energizer rigid face seal for rolling cutter drill bits with floating journal bearings. Volume balancing is accomplished by utilizing a floating static seal between the rigid face seal ring and the bearing shaft. This floating static seal ring is moved axially within a annular groove by the volume pulses caused by the axial play of the cutter when in operation. At one end of the annular groove the geometry of the rigid seal ring and bearing shaft are set such that the seal assembly achieves volume balance when the bearing is running on its OD. If the bearing is running on its OD, the floating static seal will move from where ever it is in the annular groove by the volume pulses until it reaches the balance volume position.

Abstract: The invention provides a method of detecting, at the surface, the occurrence of torsional vibration in a bottomhole assembly mounted on the drill string of a rotary drilling system. The method includes the steps of: ascertaining natural frequencies of torsional vibration of the bottomhole assembly prior to drilling, and noting at least one reference frequency for an integer wavelength mode of torsional vibration of the bottomhole assembly. During subsequent drilling, the drill string mean square torque at the surface is monitored for a bandwidth around the reference frequency. It is found that peaks in the mean square torque, close to the reference frequency, are indicative of the occurrence of torsional vibration in the bottomhole assembly.

Abstract: There is provided a rotary drag-type drill bit comprising a bit body having a leading surface comprising a plurality of pads, at least some of the pads each having a wearable abrasive surface including particles of superhard material and defining an outer profile of the pad, at least a part of the outer profile of at least one of the pads being disposed inwardly or outwardly of the outer profile of the other pads. With this arrangement, during initial drilling through softer formation, most of the removal of formation will be effected by the outermost of the abrasive pads and little or no formation will be removed by the more inward pads. Accordingly, the bit will act as a lighter set bit and good rates of penetration may be achieved.

Abstract: A wear indicator is provided for a rotary drilling tool of the type which comprises a bit body having a leading surface for cutting, abrading or reaming a hole in a target substrate material such as a sub-surface formation, the wear indicator comprising or including one or more discrete areas of a visually distinct material to that from which the drilling tool is mainly composed, the visually distinct material being arranged or configured at or adjacent the surface of the bit such that progressive wear of the bit and hence the or each visually distinct discrete area provides a visual indication of surface wear of the tool.

Abstract: A preform cutting element, for a rotary drag-type drill bit, includes a facing table of polycrystalline diamond having a front face, a peripheral surface, and a rear surface bonded to the front surface of a tungsten carbide substrate. The facing table has at least one peripheral locking portion projecting rearwardly from the rear surface of the facing table into the substrate, the inner surface of the locking portion and the adjacent part of the substrate having interengaging formations whereby part of the substrate overlies at least one part of the locking portion. With this arrangement, forces acting on the facing table tending to lift it from the front surface of the substrate are resisted by the portion of the substrate which overlies the part of the locking portion.

Abstract: Formation engaging elements are moveably mounted onto a drill bit. Such elements may be used to protect other rigidly mounted formation engaging elements from impacts that occur during use of the drill bit, or they may be used to alter the aggressiveness of the drill bit when used in directional drilling operations.

Abstract: A rotary drill bit comprises a bit body having a leading face and a gauge region, cutting elements mounted on the bit body, fluid channels extending outwardly across the leading face towards the gauge region, and nozzles for supplying fluid to the channels. At the outer end of each alternate channel, in the gauge region, is an outwardly facing junk slot which extends across only a part of the width of the channel, and a bearing surface which extends across the other part of the channel and bears against a wall of the borehole being drilled. In the channel, inwardly of the bearing surface, is an opening into an enclosed passage which passes internally through the bit body to an outlet. The bearing surfaces at the end of the channels increase the peripheral bearing surface area of the drill bit, thus improving stability, but fluid can still escape from all parts of each channel.

Abstract: A preform element, such as a preform cutting element for a rotary drag-type drill bit, includes a facing table of polycrystalline diamond having a front face, a peripheral surface, and a rear surface bonded to the front surface of a tungsten carbide substrate. The front surface of the substrate is formed with a plurality of recesses into which extend corresponding projections formed on the rear surface of the facing table. The recesses include at least one rebate which extends around only a part of the periphery of the substrate and into which extends a projection on the facing table which provides a part of the peripheral surface of the facing table.