Abstract: A method for conducting nondestructive internal inspection of a rotary drill bit used for drilling subterranean formations comprises communicating ultrasonic waves into a drill bit and detecting ultrasonic waves that are reflected by at least a portion of the drill bit. In some embodiments, the waves may be directed into the drill bit from within a longitudinal bore thereof. Reflected waves also may be detected from within the bore. The methods may be used to develop threshold acceptance criteria for classifying drill bits as acceptable or unacceptable to prevent catastrophic failures of drill bits during use. Systems and apparatuses are disclosed for conducting nondestructive ultrasonic inspection of a drill bit used for drilling subterranean formations. The systems and apparatuses may comprise an ultrasonic probe configured for insertion within an internal longitudinal bore of a drill bit. Drill bits are disclosed that are configured to facilitate nondestructive ultrasonic inspection thereof.

Abstract: A method for conducting nondestructive internal inspection of a rotary drill bit used for drilling subterranean formations comprises communicating ultrasonic waves into a drill bit and detecting ultrasonic waves that are reflected by at least a portion of the drill bit. In some embodiments, the waves may be directed into the drill bit from within a longitudinal bore thereof. Reflected waves also may be detected from within the bore. The methods may be used to develop threshold acceptance criteria for classifying drill bits as acceptable or unacceptable to prevent catastrophic failures of drill bits during use. Systems and apparatuses are disclosed for conducting nondestructive ultrasonic inspection of a drill bit used for drilling subterranean formations. The systems and apparatuses may comprise an ultrasonic probe configured for insertion within an internal longitudinal bore of a drill bit. Drill bits are disclosed that are configured to facilitate nondestructive ultrasonic inspection thereof.

Abstract: Drill bits and methods for sampling sensor data associated with the state of a drill bit are disclosed. A drill bit for drilling a subterranean formation comprises a bit body and a shank. The shank further includes a central bore formed through an inside diameter of the shank and configured for receiving a data analysis module. The data analysis module comprises a plurality of sensors, a memory, and a processor. The processor is configured for executing computer instructions to collect the sensor data by sampling the plurality of sensors, analyzing the sensor data to develop a severity index, comparing the sensor data to at least one adaptive threshold, and modifying a data sampling mode responsive to the comparison. A method comprises collecting sensor data by sampling a plurality of physical parameters associated with a drill bit state while in various sampling modes and transitioning between those sampling modes.

Abstract: A shank configuration for rotary drill bits, is disclosed for positioning of the shank in relation to the bit body. A tapered surface or feature of the shank may be configured and sized to matingly engage a complementarily shaped surface or feature of the drill bit body and thereby become centered or positioned in relation thereto. A deformable element may be disposed between the shank and bit body. Also, the shank may comprise a material having a carbon equivalent of less than about 0.35%. A multi-pass weld procedure may be employed to affix the shank and bit body to one another wherein welds may be formed so that one weld originates at a circumferential position that differs from the origination circumferential position of its immediately preceding weld by at least about 90%. Further, a stress state may be developed within the multi-pass weld. A method of manufacture is also disclosed.

Abstract: A shank configuration for rotary drill bits is disclosed for positioning of the shank in relation to the bit body. A tapered surface or feature of the shank may be configured and sized to matingly engage a complementarily shaped surface or feature of the drill bit body and thereby become centered or positioned in relation thereto. A deformable element may be disposed between the shank and bit body. Also, the shank may comprise a material having a carbon equivalent of less than about 0.35%. A multi-pass weld procedure may be employed to affix the shank and bit body to one another wherein welds may be formed so that one weld originates at a circumferential position that differs from the origination circumferential position of its immediately preceding weld by at least about 90°. Further, a stress state may be developed within the multi-pass weld. A method of manufacture is also disclosed.

Abstract: Drill bits and methods for sampling sensor data associated with a state of a drill bit are disclosed. A drill bit for drilling a subterranean formation comprises a bit configured for receiving a data analysis module. The data analysis module comprises at least one sensor, a memory, and a processor. The processor is configured for executing computer instructions to filter information derived from sensor data in the drill bit to develop a piecewise polynomial curve of the sensor data. Filtering information derived for the sensor data comprises approximating a first derivative of a sensor data waveform, calculating a plurality of zeros for the first derivative of the sensor data waveform, and fitting a cubic polynomial between adjacent zeros calculated from the first derivative of the sensor data waveform resulting in a piecewise cubic polynomial.

Abstract: Drill bits and methods for sampling sensor data associated with the state of a drill bit are disclosed. A drill bit for drilling a subterranean formation comprises a bit body and a shank. The shank further includes a central bore formed through an inside diameter of the shank and configured for receiving a data analysis module. The data analysis module comprises a plurality of sensors, a memory, and a processor. The processor is configured for executing computer instructions to collect the sensor data by sampling the plurality of sensors, analyzing the sensor data to develop a severity index, comparing the sensor data to at least one adaptive threshold, and modifying a data sampling mode responsive to the comparison. A method comprises collecting sensor data by sampling a plurality of physical parameters associated with a drill bit state while in various sampling modes and transitioning between those sampling modes.

Abstract: Drill bits and methods for sampling sensor data associated with the state of a drill bit are disclosed. A drill bit for drilling a subterranean formation comprises a bit body and a shank. The shank further includes a central bore formed through an inside diameter of the shank and configured for receiving a data analysis module. The data analysis module comprises a plurality of sensors, a memory, and a processor. The processor is configured for executing computer instructions to collect the sensor data by sampling the plurality of sensors, analyzing the sensor data to develop a severity index, comparing the sensor data to at least one adaptive threshold, and modifying a data sampling mode responsive to the comparison. A method comprises collecting sensor data by sampling a plurality of physical parameters associated with a drill bit state while in various sampling modes and transitioning between those sampling modes.

Abstract: Drill bits and methods for sampling sensor data associated with the state of a drill bit are disclosed. A drill bit for drilling a subterranean formation comprises a bit body and a shank. The shank further includes a central bore formed through an inside diameter of the shank and configured for receiving a data analysis module. The data analysis module comprises a plurality of sensors, a memory, and a processor. The processor is configured for executing computer instructions to collect the sensor data by sampling the plurality of sensors, analyze the sensor data to develop a severity index, comparing the sensor data to at least one adaptive threshold, and modifying a data sampling mode responsive to the comparison. A method comprises collecting sensor data by sampling a plurality of physical parameters associated with a drill bit state while in various sampling modes and transitioning between those sampling modes.

Abstract: A journal bearing element for use in forming a roller cone bit coupled to a bearing shaft to prevent circumferential sliding. Also included are material compositions of the journal bearing element. A journal bearing element is fixed in place relative to a head section and comprised of dense high purity powdered metal alloys with uniform micro-structure. A preferred material is comprised of a metal made of a carbon content of about 2.3% by weight, chromium of about 14% by weight, vanadium of about 9% by weight, and molybdenum at about 1% by weight.

Abstract: A shank configuration for rotary drill bits is disclosed for positioning of the shank in relation to the bit body. A tapered surface or feature of the shank may be configured and sized to matingly engage a complementarily shaped surface or feature of the drill bit body and thereby become centered or positioned in relation thereto. A deformable element may be disposed between the shank and bit body. Also, the shank may comprise a material having a carbon equivalent of less than about 0.35%. A multi-pass weld procedure may be employed to affix the shank and bit body to one another wherein welds may be formed so that one weld originates at a circumferential position that differs from the origination circumferential position of its immediately preceding weld by at least about 90°. Further, a stress state may be developed within the multi-pass weld. A method of manufacture is also disclosed.

Abstract: A casing bit, which may comprise a composite structure, for drilling a casing section into a subterranean formation, and which may include a portion configured to be drilled therethrough, is disclosed. Cutting elements and methods of use are disclosed. Adhesive, solder, electrically disbonding material, and braze affixation of a cutting element are disclosed. Differing abrasive material amount, characteristics, and size of cutting elements are disclosed. Telescoping casing sections and bits are disclosed. Aspects and embodiments are disclosed including: at least one gage section extending from the nose portion, at least one rotationally trailing groove formed in at least one of the plurality of blades, a movable blade, a leading face comprising superabrasive material, at least one of a drilling fluid nozzle and a sleeve, grooves for preferential failure, at least one rolling cone affixed to the nose portion, at least one sensor, discrete cutting element retention structures, and percussion inserts.

Abstract: A casing bit, which may comprise a composite structure, for drilling a casing section into a subterranean formation, and which may include a portion configured to be drilled therethrough, is disclosed. Cutting elements and methods of use are disclosed. Adhesive, solder, electrically disbonding material, and braze affixation of a cutting element are disclosed. Differing abrasive material amount, characteristics, and size of cutting elements are disclosed. Telescoping casing sections and bits are disclosed. Aspects and embodiments are disclosed including: at least one gage section extending from the nose portion, at least one rotationally trailing groove formed in at least one of the plurality of blades, a movable blade, a leading face comprising superabrasive material, at least one of a drilling fluid nozzle and a sleeve, grooves for preferential failure, at least one rolling cone affixed to the nose portion, at least one sensor, discrete cutting element retention structures, and percussion inserts.

Abstract: An earth-boring bit has a bit body and at least one bearing shaft depending inwardly and downwardly from the bit body. The bearing shaft has a base where it joins the bit body. At least one cutter is mounted for rotation on the bearing shaft and has radial and axial surfaces that cooperate with the base of the bearing shaft to define a bearing seal gland. A bearing is defined between the cutter and bearing shaft. A seal element is disposed in the seal gland. A secondary seal is disposed in the seal gland opposite the cutter axial surface and cooperates with the seal element to at least partially seal the gland against entry of debris from the exterior of the bit.

Abstract: An earth-boring bit has a bit body and at least one bearing shaft depending inwardly and downwardly from the bit body. The bearing shaft has a base where it joins the bit body. At least one cutter is mounted for rotation on the bearing shaft and has radial and axial surfaces that cooperate with the base of the bearing shaft to define a bearing seal gland. A bearing is defined between the cutter and bearing shaft. A seal element is disposed in the seal gland. A secondary seal is disposed in the seal gland opposite the cutter axial surface and cooperates with the seal element to at least partially seal the gland against entry of debris from the exterior of the bit.

Abstract: An improved hardfacing composition and method are shown for use in manufacturing an earth boring bit. The hardfacing composition is formed by combining titanium carbide with a hard-metal alloy of the iron or cobalt family. The hardfacing composition is then applied to the friction bearing surface of the rock bit.

Abstract: An earth boring bit having a body and a cantilevered bearing shaft extending inwardly and downwardly from the body. A rotatable cutter with an open end is assembled over the shaft, which has a journal surface formed around a longitudinal axis. The cutter has a bearing surface sized to permit assembly over the journal surface of the shaft. At the open end of the cutter bearing surface is a seal recess which includes an intersecting wall that defines an annular, generally curved corner to oppose the journal surface of the shaft. The cutter bearing surface has a curved outer region that converges from the annular corner of the seal recess into an inner region to reduce the stress the corner induces upon the journal bearing surface of the shaft, including the stress induced by cutter cocking during drilling.

Abstract: A method is shown for manufacturing rotary rock bits. The method reduces the effect of stresses in the area of the radial weld seams by providing a channel in the interior of the bit which intersects the root region of each weld, providing a generous radius for the root region of each radial weld.

Abstract: A method and device are shown for manufacturing rotary rock bits. The method eliminates repositioning errors in robotic welding operations by combining a cutting torch and a welding torch on a single, rotatable bracket whereby a bit can be welded at a single station without multiple rechuckings. The quality of the weld tie-in between any two intersecting seams (radial-radial or radial-axial) results where the groove for the latter seam in each pair is cut after the first seam in the pair has been welded.

Abstract: A method for manufacturing an earth boring drill bit and bit produced thereby are shown. The bit has rotatable cutters with a plurality of milled teeth, each of the teeth having opposing flanks. A first tube hardfacing is applied to a selected one of the opposing flanks, the hardfacing comprising a metallic binder with wear-resistant particles dispersed throughout the binder. The other of the opposing flanks has a second tube hardfacing applied thereto. The particle size of the wear-resistant particles differs between the first and second tube hardfacings so that the resulting difference in abrasion resistance of the tooth flanks produces a self-sharpening effect as the tooth wears.