Abstract: A drilling system for drilling a wellbore that includes a drill string rotatable in a first direction. The system also includes a bottom hole assembly (BHA) that includes: a drill bit, a housing with a bore, a first fluid-driven motor in fluid communication with the bore and connected with and configured to rotate a portion of the BHA in a second direction opposite the first direction, a second fluid-driven motor in fluid communication with the bore and connected with and configured to rotate the drill bit, a valve in fluid communication with a vent including a flow path arranged to direct fluid away from any one or both of the fluid-driven motors, and a controller in communication with and configured to adjust a drilling parameter of the BHA by controlling the valve to adjust a flow rate of the fluid output from the valve into the vent.

Abstract: A downhole ratchet is utilized between tubulars in the drill string to reduce torsion energy in the drill string. The downhole ratchet is constructed to release when the tubular below the ratchet spins faster than the tubular above the ratchet. When the tubular below spins more slowly or at the same speed then the ratchet mechanism locks the upper and lower tubulars together to rotate the bit. The effect is to release torsional energy in the drill string to reduce and eliminate slip stick oscillations.

Abstract: A tunable wellbore pulsation valve reduces drillstring friction in a wellbore. An upper valve plate and a lower valve plate, and upper valve plate orifice and lower valve plate orifice enabling throughflow. A Moineau motor rotates the upper valve plate while the lower valve plate remains stationary. Fluid flow causes a first fluid state of fluid passing through both the upper valve plate and the lower valve plate when the fluid passing causes rotation of the upper valve plate to align the upper valve plate orifice with the lower valve plate orifice. Increased flow efficiency produces more powerful fluid pressure pulsations and axial vibrations without increasing pump pressure at the surface of the wellbore, yielding increased wellbore friction reduction while expending the same or less energy at the surface pump than would be expended in the absence of the reduced turbulent and shear conditions and increased laminar conditions.

Abstract: A rotary actuator assembly can include a fluid motor with a rotor that displaces with hypocyclic precessional motion within a stator in response to fluid flow through the fluid motor, and a gear reducer section including an input gear that is fixed relative to the rotor and displaces with the hypocyclic precessional motion relative to an output gear. Another rotary actuator assembly can include a fluid motor with a rotor having a central longitudinal axis that rotates about a central longitudinal axis of a stator, and a gear reducer section including an input gear that rotates with the rotor and displaces relative to an output gear, and the input gear having the same central longitudinal axis as the rotor. A well system can include at least two fluid motors, and fluid flow through one fluid motor causes rotation of the other fluid motor in the well.

Abstract: Provided, in one aspect, is a drillable window assembly. The drillable window assembly, in this aspect, includes a first precut casing joint, the first precut casing joint including a first casing tubular having two or more radially offset slots along an interior surface thereof, and a second precut casing joint coupled to the first precut casing joint, the second precut casing joint including a second casing tubular having a sidewall opening formed therein. The drillable window assembly, as contained within this aspect, further includes an outer sleeve surrounding the sidewall opening in the second casing tubular.

Abstract: A concentric valve positionable in a wellbore includes a valve body including an outer surface and a central passage, a receptacle disposed in the central passage and defining a chamber disposed therein, and a radial port extending between the receptacle and the outer surface to provide fluid communication between the chamber of the receptacle and an environment surrounding the concentric valve, an inner tubular member received in the receptacle of the valve body, wherein the inner tubular member includes a seal assembly configured to sealingly engage an inner surface of the receptacle, and a bypass passage extending around the receptacle of the valve body and circumferentially spaced from the radial port, wherein the bypass passage provides fluid communication between a first end of the central passage and a second end of the central passage opposite the first end.

Abstract: An apparatus for drilling a directional wellbore is disclosed that in one non-limiting embodiment includes a drive for rotating a drill bit, a deflection device that enables a lower section a drilling assembly to tilt within a selected plane when the drilling assembly is substantially rotationally stationary to allow drilling of a curved section of the wellbore when the drill bit is rotated by the drive and wherein the tilt is reduced when the drilling assembly is rotated to allow drilling of a straighter section of the wellbore, and a sensor that provides measurements relating a direction of the drilling assembly for drilling the wellbore along a desired direction.

Abstract: A system and method to control fluid flow to downhole tools and equipment, and to allow formation testing and sampling operations is disclosed. The system includes an actuator assembly that may be mechanically or electrically activated to operate a flow diverter assembly. The flow diverter assembly may divert fluid flow to the annulus of the wellbore, to the stator of a power section, through a by-pass bore in a rotor of the power section, or any combination thereof. In the mechanically actuated actuator assembly, the actuator assembly is activated by pressure changes in the fluid introduced by cycling the pumps at the surface; and in the electrically actuated actuator assembly, the actuator assembly is activated by downlinks sent from a surface control unit or computer at the surface.

Abstract: A rotary transfer mechanism is disclosed for a motor, pump, or other downhole tool that accommodates the eccentric motion of a rotor without the need for a flex shaft, articulating joint or CV joint. In one configuration, the rotor is coupled to the drive shaft at a radial offset from the drive shaft axis. The orbiting motion of the rotor, rather than rotation of the rotor about its own axis, generates a torque on the drive shaft, by applying a tangential force to the drive shaft at the location of the radial offset. The radial offset may be set equal to the orbital radius so that no radial movement or flex is required at the drive shaft to accommodate the eccentric rotor movement.

Abstract: A stator for a downhole motor configured for use in a downhole environment. includes an inner tubular member formed from a first metallic material having an outer surface and a helically lobed inner surface, and an outer tubular member comprising a second metallic material that is different from the first metallic material. The inner tubular member is connected to the outer tubular member by compressive force passing from the outer tubular member through the inner tubular member to a rigid mandrel removably disposed within the inner tubular member. The inner tubular member and the outer tubular member form the stator of the downhole motor.

Abstract: A rotor catch system includes a catch stem having a proximal end coupled to a rotor of a mud motor system and a distal end positioned within a sub housing of a drill string, a catch feature having a top portion and a spindle portion extending from the top portion and coupled to the distal end of the catch stem, a housing catch feature extending radially inward from an inner surface of the sub housing, and a catch bushing positioned between the top portion of the catch feature and the housing catch feature. The housing catch feature restrains axial movement of the catch bushing in the active catch state via contact between the catch bushing and the housing catch feature, and the catch bushing restrains axial movement of the catch feature in the active catch state via contact between the catch feature and the catch bushing.

Abstract: Methods and apparatus for providing compliance in bearings of rotating machinery are provided. The rotating machinery may include a drive shaft movably coupled within a bearing housing. Compliant bearing assemblies may interface engagement between the drive shaft and the bearing housing, including polycrystalline diamond bearing elements, each with an engagement surface, and an opposing engagement surface of a metal that contains diamond solvent-catalyst.

Abstract: This disclosure provides an agitator system that includes an agitator assembly of concentric power-sections, (one power-section inside another power-section both of which comprise stators and rotors). The agitator system includes a controller configured to control a valve assembly of the agitator assembly to selectively open and close the valve assembly to allow fluid to selectively flow between the power-sections of the agitator assembly that generates pressure fluctuations or pressure pluses in the fluid pressure, which increases the speed of the rotor or rotors, and thus, the vibrational frequency of the agitator. The controller can be used to increase the vibrational frequency of the agitator assembly when necessary to prevent the drill string from becoming lodged in a wellbore.

Abstract: A bit saver assembly having an inner valve sleeve that actuates upon the weight-on-bit (WOB) of the drill bit exceeding a threshold value to overcome the countervailing force provided by a spring contained within the bit saver assembly and the internal flow pressure of the drilling fluid at the area of the inner valve sleeve. Actuation of the inner valve sleeve opens a fluid passage to the wellbore annulus resulting in a reduction of drilling fluid flow pressure and the stretch of the drill string thereby reducing WOB of the drill bit without operator assistance.

Abstract: The invention relates to a method, system and apparatus for determining real-time drilling operations dysfunctions by measuring the power-loss of signal propagation associated with a drill string in a wellbore. The invention comprises acquiring a first time series from a mid-string drilling sub sensor associated with a drill string in a wellbore and acquiring a second time series from a sensor associated with the drill string wherein the sensor is on or near a drill rig on the surface of the earth. The process further comprises determining the geometry of the wellbore and determining model parameters alpha and beta for characterizing a wellbore using the first time series, the second time series and the geometry of the wellbore by deriving a power loss of signal propagation. The model parameters may then be used for drilling a subsequent well using surface sensor acquired data to detect drilling dysfunctions.

Abstract: A dual-speed and dual-core enhanced drilling equipment which has an outer cylinder, a downhole power device, a large cutting head and a small cutting head. Specifically, the large cutting head has a first centerline, a through hole arranged along the first centerline and a first diameter. The outer cylinder, which is sleeved outside the downhole power device, is connected to the upper drill string with the large cutting head to enable rotation among the large cutting head, downhole power device and upper drill string. The downhole power device has a power generation section capable of generating power, and a rotation output section which connects to, and provides independent power for the small cutting head, so that the small cutting head revolves around the first centerline under the driving of the upper drill string while rotating under the driving of the downhole power device.

Abstract: A downhole motor for directional drilling includes a driveshaft assembly including a driveshaft housing and a driveshaft rotatably disposed within the driveshaft housing, a bearing assembly including a bearing housing and a bearing mandrel rotatably disposed within the bearing housing, wherein the bearing mandrel is configured to couple with a drill bit, a bend adjustment assembly configured to adjust a bend setting of the downhole motor, and an electronics package coupled to the driveshaft assembly, wherein the electronics package is configured to receive data from sensors of the downhole motor.

Abstract: In one aspect the present invention comprises a wireline retrievable coring apparatus for incorporation into a drillstring, comprising: a housing for coupling to a drill string housing, a drill bit, a turbine comprising a stator coupled to the housing and a rotor within the stator, the rotor coupled to rotate the drill bit, a core barrel through the turbine and in communication with the drill bit for capturing a core, a fluid path to the drill bit via the turbine to rotate the turbine, wherein the core barrel is rotationally isolated from the rotor and is fluidly isolated from the fluid path.

Abstract: A method and device for drilling a lateral wellbore off of a main wellbore. The device includes a guide tube for guiding a drill string to a selected location in a wellbore, the guide tube configured to support a whipstock. One or more stabilizers maintains the guide tube at an eccentric position in the wellbore. The guide tube is disposed in the main wellbore with a contact side of the guide tube against the casing. The whipstock is conveyed through the guide tube to the selected location. The drill string is conveyed through the guide tube to the selected location. The drill string is directed via the whipstock to mill an exit window in the contact side of the guide tube and the casing, thereby drilling the lateral wellbore.

Abstract: A bit jet enhancement tool is provided, the tool comprises two or more separate flow paths, each of the flow paths has multiple hollow chambers connected in series; each of the hollow chambers comprises a first constricted chamber with a fluid entry, a first expansion chamber located adjacent to the lower end of the first constricted chamber, a second constricted chamber with the upper end of connected to the lower end of the first expansion chamber; a separate second expansion chamber connected to the lower end of a plurality of the second constricted chambers; a single port located adjacent to the lower end of the second expansion chamber.

Abstract: Provided is an adjustable split thrust ring and a drilling system including the same. The adjustable split thrust ring, in one embodiment, includes a downhole split ring including two or more separate downhole pieces, the two or more separate downhole pieces fitting together to form a substantially circular downhole shoulder surrounding a substantially circular driveshaft. The adjustable split thrust ring further includes an uphole split ring positionable proximate the downhole split ring and including two or more separate uphole pieces, the two or more separate uphole pieces fitting together to form a substantially circular uphole shoulder surrounding the substantially circular driveshaft. In this embodiment, the substantially circular downhole shoulder and the substantially circular uphole shoulder are movable relative to one another to adjust to fit a groove in a driveshaft that they are configured to sit.

Abstract: A bearing assembly having independently rotatable concentric inner and outer tubes. A bearing chamber containing multiple bearings is disposed between the tubes, allowing thrust but not rotation to be transferred between them. The bearing chamber is sealed from the inside of the inner tube. To prevent high pressure fluid from leaking from the inner tube to an exterior of the tool through the bearing chamber, damaging components, a flow path is formed. An annular piston responds to high pressure within the bearing chamber and the inner tube, opening a flow path from the inner tube to the environment.

Abstract: Provided is an adjustable split thrust ring and a drilling system including the same. The adjustable split thrust ring, in one embodiment, includes a downhole split ring including two or more separate downhole pieces, the two or more separate downhole pieces fitting together to form a substantially circular downhole shoulder. The adjustable split thrust ring further includes an uphole split ring positionable proximate the downhole split ring and including two or more separate uphole pieces, the two or more separate uphole pieces fitting together to form a substantially circular uphole shoulder. In this embodiment, the substantially circular downhole shoulder and the substantially circular uphole shoulder are movable relative to one another to adjust to fit a groove in a driveshaft that they are configured to sit.

Abstract: A valve (1) controls flow of methane in automotive systems and includes at least one sealing group (98) having a proximal sealing ring (99a), in direct contact with the gas in rest conditions. A distal sealing ring (99b) is made of different materials. A check valve device (120) is applicable to the valve (1) and includes an entrance sealing group (130) provided with a proximal sealing ring (130a) and a distal sealing ring (130b) made of different materials.

Abstract: A downhole motor having an improved thread fastening structure is proposed. In the downhole motor, a thread structure disposed therein and having ridges formed at both end portions at a predetermined distance from ends is improved and the internal structures of a first coupler and a second coupler in which the end portions of the thread are respectively inserted and fastened are improved to correspond to the end portions of the thread, thereby being able to improve sealing ability.

Abstract: A system for generating pressure pulses in drilling fluid includes a concentric drive power section. The power section includes a stator and a rotor rotatably disposed in the stator. The rotor is coaxially aligned with the stator. The system also includes a valve. The valve includes a first valve member coupled to the stator and a second valve member coupled to the rotor. The second valve member is configured to rotate with the rotor relative to the first valve member and the stator. The rotation of the second valve member relative to the first valve member is configured to generate pressure pulses in drilling fluid flowing through the concentric drive power section.

Abstract: A shock and agitator tool assembly vibrates a drill string to overcome stick slip and other friction-based problems that may occur during directional drilling. The agitator tool portion of the assembly, which can be used without the shock tool, allows for controlled activation and deactivation of the agitator tool by the use of one or more darts pumped downhole. The darts can be retrieved with a wireline tool. When activated, the agitator portion creates alternating pressure pulses. These pulses cause axial movement of the drill string above the agitator. A shock tool is described which utilizes a telescoping mandrel to amplify the axial movement created by the agitator tool.

Abstract: Embodiments of the present invention are generally related to a method and apparatus for subterranean wellbores and in particular, to a method and apparatus for rotating a subsurface tubular string, such as a casing section, without rotation at the surface. More specifically, a casing section of a wellbore may be rotated to provide a cement seal with increased strength and reliability. In one embodiment, a downhole tool and rotation assembly is disclosed which imparts a torsional force to a predetermined casing section when a fluid is flowed through the downhole tool and rotation assembly.

Abstract: Tools and methods for measuring resistivity are provided. The tool for measuring resistivity in a formation comprises a receiver module comprising a first electromagnetic signal receiver and a second electromagnetic signal receiver; a first electromagnetic signal transmitter removably coupled to one longitudinal end of the receiver module; a second electromagnetic signal transmitter removably coupled to the other longitudinal end of the receiver module; and each of the first and the second electromagnetic signal receivers configured to receive electromagnetic signals propagating in the formation from the first and the second electromagnetic signal transmitters.

Abstract: A centrifugal well pump assembly has a non-rotating diffuser between upper and lower rotating impellers. The upper impeller has a cylindrical skirt on a lower side that rotates within a diffuser receptacle. The lower impeller has a cylindrical balance ring on an upper side that rotates within a diffuser cavity. Impeller sleeves are bonded to the skirt and balance ring. Diffuser sleeves are bonded to the diffuser receptacle and cavity. The diffuser sleeves are of a harder material than the impeller sleeves. Each of the impeller sleeves has upper, intermediate and lower circumferential rows of inserts. Each insert has a face flush with the impeller sleeve and is in sliding engagement with one of the diffuser sleeves. The inserts in the intermediate row may be rotationally staggered relative to the inserts in the upper and lower rows to create serpentine flow paths for well fluid leakage.

Abstract: A set of instructions stored on at least one non-transitory computer readable medium running on a computer system having at least one processor. The set of instructions extract outputs from sensors of a measurement while drilling system of a drilling rig; enable a transmitter to transmit a first data stream having at least one data series including drilling data, the first data stream having an interruptible portion encompassing at least a portion of the drilling data; detect a trigger event during transmission of the first data stream; and cease transmission of the first data stream.

Abstract: There is provided an axial vibration tool with a flow control element, a rotary motor that provides an actuation force to the flow control element, a first flow path with at least a portion in fluid communication with the rotary motor and providing fluid to drive the rotary motor. A shock tool is carried by the outer housing and generates an oscillating force based on fluid pressure applied to an activation element. A high pressure flow path is between a source of high pressure fluid and the activation element, and a low pressure flow path is between a source of low pressure fluid and the activation element. The low pressure fluid source has a lower pressure than the high pressure fluid source. The flow control element controls flow through at least the high pressure path by applying pressure fluctuations to the activation element when actuated by the rotary motor.

Abstract: A downhole steering assembly includes a steering element having an adjustable azimuthal orientation relative to a tool body. The downhole tool further includes a radio frequency identification (RFID) reader to read RFID tags arranged in an azimuthal arrangement. The downhole tool further includes an actuation mechanism that brings different RFID tags into range of the RFID reader. The downhole tool further includes a processor coupled to the RFID reader to determine an azimuthal orientation of the steering element and to responsively control the actuation mechanism.

Abstract: A valve system utilizable with a downhole tool or pulsation assembly for controlling the assembly to reduce friction on a drill string by generating pressure pulsations. The system can include a mandrel cap, and a valve. The valve can include a first end section, a valve bore defined along a longitudinal axis therethrough, one or more ports defined laterally through a sidewall of the valve and in communication with the valve bore, and a second end section defining one or more cavity sections in communication with the valve bore. At least a portion of the valve can be receivable in the cap bore, and the valve bore can be configured to receive fluid from the sub bore or the drill string. The cavity sections can be configured between an open position allowing fluid to pass therethrough and a closed position preventing fluid to pass therethrough.

Abstract: A mud-lubricated bearing section including a seal assembly for directing a fluid flowing through a mud-lubricated bearing into a central bore of a mandrel. At least one mud-lubricated bearing is positioned in an annular space between the mandrel and a housing. The seal assembly directs the fluid from the annular space through a mandrel fluid port into the mandrel central bore. The seal assembly seals the annular space, and includes a piston, a plug, and a chamber between the piston and the plug. The piston is configured for axial movement relative to the mandrel and the housing, while the plug is axially fixed relative to the mandrel and/or the housing. The chamber is configured to contain a lubricating fluid. The piston includes inner and outer seals. The plug includes a lower seal and a passage allowing the fluid from the chamber to reach the lower seal for lubrication.

Abstract: The invention relates to a hydraulic motor (2), comprising a cylindrical motor housing (201) with a central cylindrical rotor (202) carrying longitudinal vanes (208), wherein the vanes (208) are provided at the outer surface of the rotor (202) in such a manner that they can protrude into an annular space between the housing (201) and the rotor (202) in order to create a circumferential driving force on the rotor, wherein the housing (201) comprises inwards pointing salient cams (210) on its inner surface, which separate the annular space between the housing (201) and the rotor (202) into several hydraulic chambers (211) with at least one inlet (212) and at least one outlet (213) for a hydraulic medium, and the vanes (208) can swing around a longitudinal axis that is mostly parallel to the rotation axis of the rotor (202) into the hydraulic chambers (211). The invention further relates to the use of such a hydraulic motor in a drilling system, and a drilling system with such a hydraulic motor.

Abstract: A vibration assembly includes a valve above a rotor and stator. The rotor rotates within the stator as fluid flows therethrough. The valve includes a rotating valve segment, which rotates with the rotor, and a non-rotating valve segment each including at least one fluid passage. In an open position, the fluid passages of the valve segments are aligned and a fluid flows through the valve. In a restricted position, the fluid passages of the valve segments are partially or completely unaligned, thereby creating a pressure pulse that is transmitted through the drill string or coiled tubing above the valve. The valve may further include an inner sleeve and an outer sleeve surrounding the non-rotating valve segment. The inner and outer sleeves allow axial sliding but prevent rotation of the non-rotating valve segment. The assembly may further include a lower thrust bearing at a lower end of the rotor.

Abstract: A mud motor, system, and method for using same are disclosed. A mud motor can include a continuously formed power section stator housing having a first end, a second end, and an internal cavity comprising a series of stator lobes and a housing portion passing. The stator lobes can extend from the first end of the power section stator housing until a first end of a transition portion. The transition portion can form a unitary combination with the stator lobes. The mud motor further includes a rotor assembly including a power section rotor having rotor lobes to be disposed completely within the internal cavity. Additional apparatuses, systems, and methods are disclosed.

Abstract: A drill bit includes a bit body and one or more cutters positioned on the bit body at select locations. At least one vibrational device is positioned on the bit body to impart vibration to the bit body and thereby mitigate stick-slip.

Abstract: Downhole tools such as bearing assemblies and stabilizers are described for withstanding abrasive and erosive wear in operation. These stabilizers and bearing assemblies employ wear-resistant hard materials such as TSP, PCD, leached WC, and SCD composite materials. A bond between a braze material and wear tiles constructed of a hard phase material may include a non-planar interface with the braze material. Self-lubricating materials may be provided within the braze material or the hard material in some instances.

Abstract: Embodiments of the invention relate to bearing apparatuses in which one bearing surface of the bearing apparatus includes diamond, while another bearing surface includes a non-diamond superhard material (e.g., silicon carbide). For example, a bearing apparatus may include a bearing stator assembly and a bearing rotor assembly. The bearing stator assembly and bearing rotor assembly each include a support ring and one or more superhard bearing elements generally opposed to one another. The bearing surface(s) of the rotor or stator may include diamond, while the bearing surface(s) of the other of the rotor or stator do not include diamond. Another bearing apparatus may include both thrust- and radial bearing components. The generally opposed thrust-bearing elements may include diamond, while the generally opposed radial bearing elements may not include diamond, but include a non-diamond superhard material, such as silicon carbide.

Abstract: A drill tool that is usable in drilling a wellbore can include a pin component and a box component. The pin component has a threaded portion and an extended portion extending axially from an end of the threaded portion. The box component is part of a stator of a downhole drilling motor. The box component is threadedly coupled to the pin component such that the extended portion of the pin component is positioned in an inner area defined by the box component to absorb stress from the threaded portion during a bend for a wellbore drilling operation.

Abstract: A downhole assembly and method are provided for selective activation of a motor in a drilling string. The downhole assembly includes a stator and a rotor assembly. The rotor assembly comprises a rotor body having a fluid passage extending between an inlet and an outlet, the fluid passage extending through at least part of the length of the rotor; and a ball catch component comprising a receiving end and an interior seat for receiving and retaining a blocking implement, and a fluid passage. When no blocking implement is retained in the rotor assembly, the fluid passage permits flow of drilling fluid entering the receiving end to the fluid passage of the rotor body. The fluid thereby bypasses the motor, which is not activated. When a blocking implement is in place, drilling fluid flows around the ball catch component and into the motor to thereby activate the motor.

Abstract: A drilling system, rotating control device, and a method for accessing a wellbore may employ a rotating control device arranged to form a dynamic seal between the housing and an exterior of the string to isolate the wellbore annulus under both a positive and a negative differential pressure across the seal. The rotating control device may including a sleeve rotatively disposed within the housing and rotatively carried near a longitudinal midpoint of the sleeve by a thrust bearing assembly. One or more seal retainers may be coupled to and sealed against the sleeve, each including a resilient element disposed to slide to a first sealing position within the seal retainer under a positive differential pressure across the element and to slide to a second sealing position within the seal retainer under a negative differential pressure across the element.

Abstract: A sealing device for a system for applying a liquid coating product comprises an inner conduit suitable for sealably surrounding an actuating rod of the application system, a frame and a sealing gasket made from a synthetic material comprising an O-ring mounted around a lip of the gasket suitable for being pressed against the actuating rod, the frame and the gasket forming a single-piece assembly suitable for being mounted in a housing of the application system.

Abstract: A fluid pressure pulse generator for a downhole telemetry tool comprising a stator and a rotor. The stator comprises a stator flow diverter radially extending across a flow path for fluid flowing through the fluid pressure pulse generator and having one or more than one stator flow channel therethrough through which the fluid flows. The rotor comprises a rotor flow diverter radially extending across the flow path for fluid flowing through the fluid pressure pulse generator and having one or more than one rotor flow channel therethrough through which the fluid flows. The rotor flow diverter is axially adjacent the stator flow diverter and the rotor flow diverter is rotatable relative to the stator flow diverter to move the one or more than one rotor flow channel in and out of fluid communication with the one or more than one stator flow channel to create fluid pressure pulses in the fluid flowing through the fluid pressure pulse generator.

Abstract: A downhole vibration tool that permits tool retrieval therethrough has an outer housing with an inner bore and a longitudinal axis, a rotating impeller that rotates within the inner bore of the outer housing, the rotating impeller defining an outer flow passage and an inner flow passage nested within the outer flow passage. The rotating impeller carries impeller vanes that are angled relative to a rotational axis and that extend into the outer flow passage such that fluid passing through the outer flow passage impinges on the impeller vanes to cause the rotating impeller to rotate. A flow restrictor having a variable flow area is positioned in the outer flow passage adjacent to the impeller vanes, and the rotation of the impeller vanes causes the flow area of the flow restrictor to periodically increase and decrease.

Abstract: A well tool apparatus comprises a control arrangement configured to control response of the downhole tool by varying a bore-annulus pressure difference. The control arrangement includes a valve piston longitudinally slidable in a generally tubular controller housing that is in operation substantially co-axial with the wellbore, to open or close a valve port to a fluid flow connection between the drill strings interior and the tool. A latch mechanism is configured to latch the valve piston against movement in one axial direction, keeping the valve piston in an open or a closed condition. Unlatching of the valve piston requires displacement thereof in the other axial direction to a mode change position. A stay member is automatically displaceable under hydraulic actuation responsive to bore-annulus pressure differences above a trigger threshold value, to obstruct movement of the latched valve piston under hydraulic actuation to the mode change position.

Abstract: A rotor catch assembly for connection in a workstring in a wellbore is provided. The rotor catch assembly is connected to a downhole motor assembly that includes a rotor that is driven by a fluid. In the normal operating state of the rotor catch assembly, fluid flows through the catch assembly and causes the rotor to rotate. In this state, the catch assembly generates pressure pulses in the fluid in the workstring to facilitate advancement of the workstring in the wellbore. In the event of a failure of a mechanical connection in the motor assembly, the rotor catch assembly shifts to a catch-activated state in which the motor assembly is disabled.

Abstract: A drive shaft for a machine tool is connectable to a drilling tool. The drive shaft contains a cavity extending substantially over the entire length of the drive shaft and along the axis of rotation where the cavity contains an inflow opening through which water can be fed along the drive shaft into the drilling tool. An insert device is provided in the cavity, through which, to cool the drive shaft, the water is guided first in a first direction and then in a second direction where the insert device contains a first curved guide element and a second curved guide element for separating the water which is guided in the first direction from the water which is guided in the second direction. The cross-sectional area of the first curved guide element is designed point-symmetrically about a center longitudinal axis to the cross-sectional area of the second curved guide element.