Abstract: A cutting bit includes a bit body and high-pressure body with a high-pressure fluid conduit therethrough. The high-pressure body and bit body are joined together. The high-pressure fluid conduit is configured to convey a fluid at greater than 14.5 ksi, and in some embodiments greater than 40 ksi. The high-pressure fluid conduit may direct the fluid through a nozzle in a fluid jet to weaken material, such as an earth formation. The cutting bit includes at least one roller cone and/or blades with cutting elements thereon to remove the weakened material. A cutting bit includes both high and low-pressure fluid conduits, and high and low-pressure fluid nozzles. The high-pressure nozzles receive fluid flow from a downhole pressure intensifier, and a connection between the bit and the downhole pressure intensifier includes rigid connectors, flexible connectors, or a combination thereof.

Abstract: A spray tip comprises a tip body, a tip piece, and a pre-orifice piece. The tip body has a fluid channel along a channel axis (AC). The tip piece is disposed within the fluid channel, and has a stepped, narrowing passage that terminates in an outlet orifice. The pre-orifice piece has an inlet passage, and is disposed within the fluid channel, abutting and immediately upstream of the tip piece. The pre-orifice piece and the tip piece together define a turbulating chamber therebetween.

Abstract: Earth-boring drill bits include a bit body, an element having an attachment feature bonded to the bit body, and a shank assembly. Methods for assembling an earth-boring rotary drill bit include bonding a threaded element to the bit body of a drill bit and engaging the shank assembly to the threaded element. A nozzle assembly for an earth-boring rotary drill bit may include a cylindrical sleeve having a threaded surface and a threaded nozzle disposed at least partially in the cylindrical sleeve and engaged therewith. Methods of forming an earth-boring drill bit include providing a nozzle assembly including a tubular sleeve and nozzle at least partially within a nozzle port of a bit body.

Abstract: A downhole drilling tool and methods for using the tool include a body with a wall that defines an internal volume, and at least one arm attached to the wall, the at least one arm comprising a channel within a body of each arm. The at least one arm provides fluid paths connecting the internal volume to outside the wall, and the at least one arm is displaceable relative to the wall.

Abstract: A nozzle for a drill bit such as may be used to drill for oil or natural gas. The nozzle includes a generally-cylindrical body having a longitudinal axis, a proximal end for insertion into a drill bit body, and a distal end opposite the proximal end. The nozzle body defines a longitudinal bore through the nozzle along the longitudinal axis. The nozzle further includes one or more lobes extending radially from the nozzle body near the distal end. Each of the lobes is displaced axially from the distal end such that a cylindrical portion of the nozzle body is disposed between the distal end and the lobe. The nozzle further includes a fitting in the distal end configured to engage a tool for imparting rotational torque to the nozzle about the longitudinal axis. Such a nozzle is preferably insertable into a drill bit body from outside the body.

Abstract: Earth-boring rotary drill bits include heel portions exhibiting reduced aggressiveness. Earth-boring rotary drill bits may comprise a bit body and a plurality of roller cones coupled to the bit body. Each roller cone comprises a plurality of rows of cutting elements, and a continuous disk heel located further from an axis of rotation of the roller cone than the at least one row of cutting elements, the continuous disk heel exhibiting a reduced amount of aggressiveness compared to the at least one row of cutting elements.

Abstract: A rock bit for blast hole drilling includes: a bit body having a coupling formed at an upper end thereof, a plurality of lower legs, a dome formed between the legs, and a bore formed through the coupling and the dome; a plurality of skirts, each skirt covering a gap formed between adjacent legs and each skirt mounted to edges of adjacent legs; a plurality of roller cones, each rotary cone rotatably mounted to a respective bearing shaft of a respective leg; a row of gage cutters mounted to each roller cone; a row of inner cutters mounted to each roller cone; one or more nose cutters mounted to each roller cone; and a center jet secured in the bore. Each cutter is an insert.

Abstract: An earth boring bit has rotary cutters with embedded tungsten carbide inserts and milled steel teeth. The teeth and the grooves are first milled into the cutters, with the grooves extending between bases of the teeth, parallel to the crests of the teeth. Hard facing is applied to surfaces of the teeth and the grooves, and then the cutters are heat treated. Insert sockets are drilled into the teeth, centrally disposed in crests of the teeth. The tungsten carbide inserts are secured in the insert sockets, aligned for forming cutting profiles with respective ones of the milled teeth. The cutters are preferably frustoconically shaped and used for a rotary cone rock bit, and the tungsten carbide inserts configured as chisel-shaped inserts having crests which are aligned parallel to the crests of the milled steel teeth.

Abstract: An earth-boring bit includes a bit body threaded at its upper extent for connection to a drill string and a plurality of blades on the bit body, each blade having a leading edge and a trailing edge. A plurality of cutting elements is arranged on the leading edge of each blade and a junk slot is defined between pairs of adjacent blades. A surface texture may be formed on the surface of the junk slot, the surface texture being selected to alter a flow of drilling fluid through the junk slot. At least one milling element may extend at least partially across the junk slot between the trailing edge and leading edge of adjacent blades, wherein flow of cuttings generated by the cutting elements is impeded until the cuttings are disintegrated to a selected size.

Abstract: An apparatus for horizontal directional drilling includes a housing and a sonde transmitter mounted in the housing. The housing includes a main fluid channel to permit a flow of a fluid therethrough. The apparatus further includes a fluid outlet at the front of the housing in communication with the main fluid channel and adapted to emit fluid from the front of the housing during pilot bore operations. The housing further includes a plurality of fluid ports in fluid communication with the main fluid channel and adapted to emit fluid from the housing during pullback operations. Drill bits, drill bit adapters, swivel connectors, and tow heads adapted to be coupled to the drill bits for direct pullback operations, as well as methods of direct pullback operations during horizontal direction drilling are also provided.

Abstract: An earth-boring rotary tool includes a tool body, at least one fixed blade associated with the tool body and configured to carry a fixed cutting element, and at least one leg configured to carry a rolling cutter. The tool body has a slot extending longitudinally generally parallel to a longitudinal axis defining an axial center of the tool body. The slot is at least partially defined by a first sidewall, a second sidewall opposing the first sidewall, a third sidewall extending between the first sidewall and the second sidewall, and an axial end wall of the tool body. A portion of the leg is disposed within the slot of the tool body and abuts the first sidewall of the tool body. A wedge is disposed within the slot and pins the leg to the tool body within the slot.

Abstract: A modular hybrid drill bit is disclosed comprising a plurality of fixed blades and at least one rolling cutter assembly that is mechanically fastened to a bit body by a plurality of mechanical fasteners. The at least one rolling cutter assembly can be adjusted to change the axial and radial exposure of the rolling cutter elements.

Abstract: A fluid jet nozzle for a decoking tool, a decoking tool and method of operating same. The nozzle includes a nozzle assembly for use in a fluid jet decoking tool. The assembly includes a housing to hold one or more nozzles that are used to spray or otherwise distribute decoking fluid. An internal flowpath that extends from an inlet of the nozzle to an outlet of the nozzle defines a tapered shape such that when the decoking fluid passes through the nozzle, the flowpath produces a predominantly coherent flow pattern in the fluid.

Abstract: A method of securing a nozzle in an end of a slurry discharge tube can include inserting the nozzle into the end of the slurry discharge tube, and crimping the slurry discharge tube onto the nozzle. A well screen shunt tube assembly can include a slurry discharge tube, and a nozzle inserted into an end of the slurry discharge tube, the slurry discharge tube being crimped onto the nozzle.

Abstract: A curved nozzle for use in a drill bit is disclosed. The curved nozzle includes a flow path that directs drilling fluid towards the face of cutters. The curved nozzle may include a base, neck, and a tip. Flow entering the nozzle, travels along a flow path through the nozzle and out the tip. The flow path may be reduced as it passes through the nozzle. The flow is curved as it flows through the neck and out the tip. The nozzle includes cooperating interior surfaces that guide the flow. The upper interior surface may include two curved zones. The first zone will be a substantially constant radius of curvature. The second zone, extending from the first zone, may be straight.

Abstract: Methods include: forming a first mud filtercake with a first mud; and determining a relationship between an impinging jet of a fluid at varying pressures against a surface of the first mud filtercake to a first erosion characteristic of the first mud filtercake. In various embodiments, the methods can additionally include: using the first erosion characteristic to design an operation to remove a second mud filtercake formed or to be formed in a wellbore with a second mud.

Abstract: An apparatus for horizontal directional drilling includes a housing and a sonde transmitter mounted in the housing. The housing includes a main fluid channel to permit a flow of a fluid therethrough. The apparatus further includes a fluid outlet at the front of the housing in communication with the main fluid channel and adapted to emit fluid. from the front of the housing during pilot bore operations. The housing further includes a plurality of fluid ports in fluid communication with the main fluid channel and adapted to emit fluid from the housing during pullback operations. Drill bits, drill bit adapters adapters, swivel connectors, and tow heads adapted to be coupled to the drill bits for direct pullback operations, as well as methods of direct pullback operations during horizontal direction drilling are also provided.

Abstract: A drill bit for forming a hole in a formation. The drill bit has a shank and a full face crown that cooperate to define an interior space that receives water or other drilling fluid. The full face crown defines a plurality of bores that extend from a cutting face of the full face crown to the interior space. The full face crown completely circumferentially encloses the interior space of the drill bit.

Abstract: An earth boring drill bit having an alternate path to allow cuttings to be ejected or evacuated from the drill bit and up the bore hole is disclosed. The evacuation hole of the present disclosure allows larger sized cuttings to evacuate from the bit without having to be continually ground by rolling cone cutters until the cuttings are small enough to follow a path around the edge of the shirttail of the bit and up the borehole. A cuttings restrictor is disposed at the inlet of the evacuation hole. The cuttings restrictor ensures that only cuttings that are sized to move completely through the evacuation hole and exit the drill bit are allowed to enter the evacuation hole.

Abstract: An underwater drilling arrangement for marking a bore in a bed of a lake, sea or river with a service platform which can be lowered for placing on the lake, sea or river bed, a drill drive which is mounted so that it is axially displaceable on the service platform, and a drill rod with drill head which can be driven in rotation via the drill drive. A conveying channel is formed in the drill rod, through which a conveying fluid together with excavated drill cuttings can be conveyed upwards, and a discharge opening for the conveying fluid together with the excavated drill cuttings is provided, via which the conveying fluid can be discharged underwater together with the excavated drill cuttings above the drill drive.

Abstract: A rolling cone drill bit for drilling in earthen formations having a plurality of rolling cone cutters. Each cone cutter includes a plurality of gage cutting elements, a first plurality of bottomhole cutting elements, and a second plurality of bottomhole cutter elements. Each of the first plurality of bottomhole cutting elements is staggered relative to the gage cutting elements on each cone cutter. Each of the second plurality of bottomhole cutting elements is staggered relative to the first plurality of bottomhole cutting elements on at least one cone cutter.

Abstract: A drill bit is disclosed, comprising: a drill bit head having a cutting face with one or more fixed cutting elements; a flow passage extending through the drill bit head to the cutting face; a flow interrupter within the drill bit head and positioned to interrupt flow of fluid through the flow passage; and a power section connected to drive the flow interrupter and cause, in operation, variable flow of fluid through the flow passage. A method of drilling is also disclosed comprising: flowing fluid through a flow passage extending through a drill bit head to a cutting face of the drill bit head, the cutting face having one or more fixed cutting elements; and driving a flow interrupter within the drill bit head with a power section to interrupt the flow of fluid through the flow passage and cause variable flow of fluid through the flow passage.

Abstract: A non-cylindrical nozzle socket and a downhole tool that includes a non-cylindrical nozzle socket. The non-cylindrical nozzle socket includes a base and a nozzle socket wall that extends outwardly from the base. The nozzle socket wall includes a distal end positioned away from the base. The distal end forms an opening larger than the area of the base.

Abstract: Disclosed is a rolling cone drill bit with inner row cutting teeth having portions shielded with an erosion-resistant material that differs in material properties from the tooth's core portion that is more impact resistant. The tooth includes shielding on at least a portion of the upstream end and along portions of the flanking surfaces. It includes shield-free portions on the flanks between the root and the tooth crest. Most of the tooth's perimeter is made of the core material and is free of shielding. Gage row teeth may be angled and form a channel to direct drilling fluid from the gage region of the borehole to locations where the inner row teeth are generating most cuttings. Nozzles are provided with non-uniform orientations.

Abstract: A tricone rock bit for horizontal wells and hard formation wells includes three head sections and three cones arranged at the lower ends of the head sections, where the supper parts of the three head sections are connected together to form one integrated drill bit body; jet nozzle bosses are arranged between the head sections on the drill bit body; jet nozzles are mounted in nozzle holes of the jet nozzle bosses; gauge cutting elements are arranged on the top rear of the OD of the head sections, forming a gauge surface on the top of the head sections; the front face of the head sections is a ruled surface, inclining backwards at an angle ?, and inclining outwards at an angle ?. The tricone rock bit has low lateral vibrations, high stability, good effects of bottom hole cleaning and cutting element cooling, long service life and high penetration rate.

Abstract: A drill bit comprises: a drill bit head having a cutting face with one or more fixed cutting elements; a flow passage extending through the drill bit head to the cutting face; a flow interrupter within the drill bit head and positioned to interrupt flow of fluid through the flow passage; and a power section connected to drive the flow interrupter and cause, in operation, variable flow of fluid through the flow passage. A method of drilling comprises: flowing fluid through a flow passage extending through a drill bit head to a cutting face of the drill bit head, the cutting face having one or more fixed cutting elements; and driving a flow interrupter within the drill bit head with a power section to interrupt the flow of fluid through the flow passage and cause variable flow of fluid through the flow passage.

Abstract: A rotating cone drill bit includes a plurality of mud nozzles extending from the bit body, which are thermally fitted by controlling the temperature differential depending on the corresponding materials, the amount of fit desired, and the diameters of the elements to be fitted and which provide substantially obstruction-free mud paths toward the wellbore bottom. The bit has a plurality of reduced diameter cutter assemblies, each having a journal projecting from a corresponding leg. The journal has at least two cylindrical bearing surfaces and an annular groove formed therebetween and a spindle. An annular retention segment is rotatably mounted in the groove. The retention segment has an outer radial surface engaging a portion of one of the bearing surfaces of the cone, and an energy beam welding area fusing substantially the entire engaging surfaces of the retention segment and the cone.

Abstract: A roller cone bit is described. The roller cone bit includes a body having concave sides. Legs are attached or integral to the body. Roller cones are rotatably engaged to the legs. The concave sides are positioned adjacent the legs. A nozzle is positioned in an approximately central portion of the body.

Abstract: A rotary drill bit having one or more fluid nozzles is provided. Each nozzle may include interior surfaces designed to optimize hydraulic performance and efficiency of fluid flowing through the nozzle. The interior surfaces cooperate with each other to minimize turbulent fluid flow through the respective nozzle. Each nozzle may also include a discharge port or outlet with at least one Coanda surface operable to direct fluid flow in a direction which optimizes efficiency of transferring fluid energy to adjacent portions of a wellbore. The orientation of fluid flow from each nozzle may be directed to optimize cleaning of associated cutting structures and/or to minimize or prevent balling of formation cuttings.

Abstract: A rotating cone drill bit includes a plurality of mud nozzles extending from the bit body, which are thermally fitted by controlling the temperature differential depending on the corresponding materials, the amount of fit desired, and the diameters of the elements to be fitted and which provide substantially obstruction-free mud paths toward the wellbore bottom. The bit has a plurality of reduced diameter cutter assemblies, each having a journal projecting from a corresponding leg. The journal has at least two cylindrical bearing surfaces and an annular groove formed therebetween and a spindle. An annular retention segment is rotatably mounted in the groove. The retention segment has an outer radial surface engaging a portion of one of the bearing surfaces of the cone, and an energy beam welding area fusing substantially the entire engaging surfaces of the retention segment and the cone.

Abstract: Roller cone drill bits operable to form a borehole. A number of support arms may extend from each drill bit. A cutter cone assembly may be mounted on each support arm. A number of cutting elements or inserts may be disposed on an exterior surface of a cone assembly. A lifting surface may be formed on each support arm extending between a leading edge and a trailing edge of each support arm such that the lifting surfaces directs cuttings upward in a borehole. A wedge shaped portion may be formed on each support arm proximate the lifting surface and the trailing edge. An inlet to each lifting surface may be formed on the leading edge of each support arm.

Abstract: In one aspect of the present invention, a downhole rotary steerable system comprises a fluid path defined by a bore formed within a drill string component. A valve located within a wall of the bore which hydraulically connects the bore with a fluid cavity. A steering nozzle disposed on the drill string component and in communication with the fluid cavity. The valve is configured to control flow from the bore to the fluid cavity with an azimuthal sensing mechanism configured to determine the azimuth of the steering nozzle and instrumentation configured to control the valve based off of input from the azimuthal sensing mechanism.

Abstract: Earth-boring drill bits include a bit body including a blockage-resistant internal fluid passageway. The blockage-resistant internal fluid passageway includes at least one internal fluid passageway formed in the bit body and a cuttings filtering feature formed in the at least one internal fluid passageway configured to prevent at least some cuttings from flowing through the at least one internal fluid passageway. In one embodiment, the cuttings filtering feature includes at least one lateral member extending transversely across the at least one internal fluid passageway. In another embodiment, the cuttings filtering feature includes forming a central portion of the at least one internal fluid passageway with a width along a lateral axis thereof less than an average width of a fluid path extending through a nozzle disposed at least partially within the at least one internal fluid passageway. Methods of forming the blockage-resistant internal fluid passageway are also disclosed.

Abstract: Disclosed is a rolling cone drill bit with inner row cutting teeth having portions shielded with an erosion-resistant material that differs in material properties from the tooth's core portion that is more impact resistant. The tooth includes shielding on at least a portion of the upstream end and along portions of the flanking surfaces. It includes shield-free portions on the flanks between the root and the tooth crest. Most of the tooth's perimeter is made of the core material and is free of shielding. Gage row teeth may be angled and form a channel to direct drilling fluid from the gage region of the borehole to locations where the inner row teeth are generating most cuttings. Nozzles are provided with non-uniform orientations.

Abstract: A rotating cone drill bit includes a plurality of mud nozzles extending from the bit body, which are thermally fitted by controlling the temperature differential of 300° F.-900° F. depending on the corresponding materials of the elements to be fitted, the amount of fit desired, and the diameters of the elements to be fitted and which provide substantially obstruction-free mud paths toward the wellbore bottom. The bit has a plurality of reduced diameter cutter assemblies, each having a journal projecting from a corresponding leg. The journal has at least two cylindrical bearing surfaces and an annular groove formed therebetween and a spindle. An annular retention segment is rotatably mounted in the groove. The retention segment has an outer radial surface engaging a portion of one of the bearing surfaces of the cone, and an energy beam welding area fusing substantially the entire engaging surfaces of the retention segment and the cone.

Abstract: The present disclosure relates methods and apparatuses for testing and sampling of underground formations or reservoirs. The apparatus may include at least one extendable element configured to penetrate a formation. The at least one extendable element may include at least one drill bit with a nozzle configured to receive formation fluids. The at least one extendable element may include at least one sensor disposed on the at least one extendable element. The at least one extendable element may also include a source of stimulus for stimulating the formation. The at least one extendable element may be configured to detach and/or attach from/to a bottom hole assembly (BHA). One method may include steps for performing testing on the formation for estimating a parameter of interest of the formation. Another method may include steps for performing testing to estimate a parameter of interest of the formation fluid.

Abstract: Apparatus and methods for drilling with casing. In an embodiment, methods and apparatus for deflecting casing using a diverter apparatus are disclosed. In another embodiment, the apparatus comprises a motor operating system disposed in a motor system housing, a shaft operatively connected to the motor operating system, the shaft having a passageway, and a divert assembly disposed to direct fluid flow selectively to the motor operating system and the passageway in the shaft. In another aspect, methods and apparatus for directionally drilling a casing into the formation are disclosed. Methods and apparatus for measuring the trajectory of a wellbore while directionally drilling a casing into the formation are also described.

Abstract: A rotary drill bit having one or more fluid nozzles is provided. Each nozzle may include interior surfaces designed to optimize hydraulic performance and efficiency of fluid flowing through the nozzle. The interior surfaces cooperate with each other to minimize turbulent fluid flow through the respective nozzle. Each nozzle may also include a discharge port or outlet with at least one Coanda surface operable to direct fluid flow in a direction which optimizes efficiency of transferring fluid energy to adjacent portions of a wellbore. The orientation of fluid flow from each nozzle may be directed to optimize cleaning of associated cutting structures and/or to minimize or prevent balling of formation cuttings.

Abstract: A drill bit for enhancing drilling operations, where the drill bit includes a bit body configured for coupling to a drillstring, and a bit face disposed on an end of the bit body with at least one cutting structure attached thereto. There is a fluid guide operatively connected to the drill bit and disposed above the end of the bit body, where the fluid guide includes at least one nozzle disposed therein that is in fluid communication with a fluid cavity disposed in the drill bit, and where the fluid guide is configured to induce distribution of fluid flow in a flow regime above the drill bit.

Abstract: A drill bit for drilling through an earthen formation to form a borehole includes a bit body having a central axis, an internal plenum, and an underside. The underside includes an annular outer region. The bit body includes an outer receptacle extending from the plenum to the outer region. In addition, the drill bit comprises a first and a second cone cutter. Each cone cutter comprises an outer region distal the bit axis. Further the drill bit comprises an outer sleeve having an upstream end received by the outer sleeve receptacle and a through passage. The through passage includes an upstream section having an upstream axis and a downstream section having a downstream axis that is skewed at an angle ? relative to the upstream axis. A projection of the downstream axis passes between the outer regions of the first and second cone cutters.

Abstract: A rotary drill bit having one or more fluid nozzles is provided. Each nozzle may include interior surfaces designed to optimize hydraulic performance and efficiency of fluid flowing through the nozzle. The interior surfaces cooperate with each other to minimize turbulent fluid flow through the respective nozzle. Each nozzle may also include a discharge port or outlet with at least one Coanda surface operable to direct fluid flow in a direction which optimizes efficiency of transferring fluid energy to adjacent portions of a wellbore. The orientation of fluid flow from each nozzle may be directed to optimize cleaning of associated cutting structures and/or to minimize or prevent balling of formation cuttings.

Abstract: The blades of a PDC bit have a nozzle between them preferably oriented laterally across the plane of the cutters on the blade and more preferably in a trough disposed adjacent the row of cutters. The cutting is less likely to adhere to the bit surface because the trough abruptly spaces back the bit surface and the spray being oriented radially preferably into the trough gets between the bit surface and the cutting before it can adhere to the bit surface using the fluid energy to drive the cutting into the junk slot.

Abstract: In one aspect of the invention, a downhole centrifugal drilling fluid separator has a bore within a tubular body comprising a central axis. The bore is formed to receive drilling fluid comprising particulate matter. At least one fin rigidly fixed within the bore and at least one port formed in a wall of the tubular body. As the drilling fluid flows through the tubular body the at least one fin creates a rotary motion within the drilling fluid forcing a portion of the particulate matter away from the central axis and through the at least one port in the tubular body.

Abstract: A steel body bit nozzle assembly comprising a bit body having a port therein with a sleeve disposed adjacent a nozzle in the port and an annular seal disposed between an outer wall, each of the sleeve and the nozzle and a wall of the port, each seal being received and compressed in an annular seal groove located between its respective component and the bit body. A nozzle pocket insert assembly and a method of manufacturing or retrofitting a steel body bit for use of the nozzle pocket insert assembly are also disclosed.

Abstract: A rotating cone drill bit includes a plurality of mud nozzles extending from the bit body, which are thermally fitted by controlling the temperature differential of 300° F.-900° F. depending on the corresponding materials of the elements to be fitted, the amount of fit desired, and the diameters of the elements to be fitted and which provide substantially obstruction-free mud paths toward the wellbore bottom. The bit has a plurality of reduced diameter cutter assemblies, each having a journal projecting from a corresponding leg. The journal has at least two cylindrical bearing surfaces and an annular groove formed therebetween and a spindle. An annular retention segment is rotatably mounted in the groove. The retention segment has an outer radial surface engaging a portion of one of the bearing surfaces of the cone, and an energy beam welding area fusing substantially the entire engaging surfaces of the retention segment and the cone.

Abstract: A reamer bit for use in earth boring operations comprising a body, mounting elements on the bit body having rolling cutters, and nozzles configured to emit a cleaning spray that is angled with respect to the well bottom. The cleaning spray may be angled up to about 20° with respect to the well bottom. The reamer may further include a pilot bit on a drill pipe extending downward from the reamer body.

Abstract: A rotary drill bit having one or more fluid nozzles is provided. Each nozzle may include interior surfaces designed to optimize hydraulic performance and efficiency of fluid flowing through the nozzle. The interior surfaces cooperate with each other to minimize turbulent fluid flow through the respective nozzle. Each nozzle may also include a discharge port or outlet with at least one Coanda surface operable to direct fluid flow in a direction which optimizes efficiency of transferring fluid energy to adjacent portions of a wellbore. The orientation of fluid flow from each nozzle may be directed to optimize cleaning of associated cutting structures and/or to minimize or prevent balling of formation cuttings.

Abstract: A system for use in excavating a wellbore that includes a drill string and attached drill bit that has nozzles that are in fluid communication with the drill string. The system receives pressurized slurry of fluid and impactor particles and directs the slurry at a subterranean formation from the nozzles to form the wellbore. Discharge streams are formed from the slurry exiting the nozzles, the discharge streams impact and fracture the formation to remove material. The nozzles are oriented so that the streams excavate in the middle and periphery of the borehole bottom. The nozzles can be oriented to form frusto-conical spray patterns when the bit is rotated, wherein the spray patterns can intersect or overlap.

Abstract: Novel nozzles are disclosed that include flutes and/or baffles having cross-sections that undergo a rotation from a nozzle inlet to a nozzle outlet to produce fluid flows having a velocity profile including both linear and angular velocity components.

Abstract: Flow tubes for earth-boring tools include hardfacing material for protecting the tubes from erosion due to the flow of fluid through a fluid passageway extending therethrough. Earth-boring tools include an erosion-resistant material covering a surface of a body of the tools for protecting the bodies from erosion due to the flow of fluid through a fluid passageway extending therethrough. Methods of forming earth-boring tools include forming a body having a fluid passageway extending therethrough and covering a surface of the body with a hardfacing material. The surface of the body may be located in a region susceptible to erosion when fluid is caused to flow through the fluid passageway.