Abstract: A vehicle damper is described. The vehicle damper includes: a cylinder; a piston within the cylinder; a working fluid within the cylinder; a reservoir in fluid communication with the cylinder via the working fluid, the reservoir operable to receive the working fluid from the cylinder in a compression stroke; a valve in a flow path between the cylinder and the reservoir; and a remotely-operable valve having a position allowing the working fluid to significantly by-pass the valve.

Abstract: A downhole power drilling tool includes a flow distribution shaft, an outer pipe and a multi-stage eccentric gear driving mechanism which are coaxially arranged, the flow distribution shaft is suspended and supported in the outer pipe by the multi-stage eccentric gear driving mechanism.

Abstract: A downhole power generation system is disclosed, which includes a turbine generator system. The turbine generator system includes a turbine, a generator coupled with the turbine and having an AC-DC rectifier, and an optimized power control unit. The turbine is driven by flow of a downhole fluid to rotate. The generator converts rotational energy from the turbine to electrical energy and outputting a direct current voltage. The turbine generator system is coupled to a load via the optimized power control unit. The optimized power control unit controls to regulate an output voltage of the generator and provides a regulated output voltage to the load so that the turbine generator system has an optimized power output. An optimized power control method for a downhole power generation system is also disclosed.

Abstract: A wellbore assembly includes a conveyance member including at least one of a continuous spooled rod, a wireline, and a slickline; an accumulator system connected to the conveyance member; and a setting tool connected to the accumulator system. The accumulator system may be configured to supply a fluid pressure to actuate the setting tool. A method of operating a wellbore tool includes lowering a wellbore assembly into a wellbore using a conveyance member including at least one of a continuous spooled rod, a wireline, and a slickline, wherein the wellbore assembly includes an accumulator system and a setting tool. The method includes actuating the accumulator system to provide a fluid pressure to the setting tool. The method also includes actuating the setting tool using the fluid pressure.

Abstract: A system and method are provided for delivering current to a lower exposed end of a well in which a source of current is connected to a middle section of a well casing or tubing inserted in the casing with the middle section being electrically isolated from a first or upper section by an insulative coupler and treated to be electrically resistive. A cable is attached to the middle section and used to deliver current along the wall of the middle section to the lower exposed end such that the lower exposed end is used to generate an electric field in nearby geological zones. Changes in the generated electric field resulting from the nature of materials in the geological zones can be detected by surface or below ground monitors or sensors.

Abstract: According to one embodiment, a multiple motor and/or pump array module for a drilling tool comprises a plurality of motors and/or pumps extending axially along generally parallel axes wherein the pumps are positioned along the axes next to each other in a parallel manner in generally the same axial location.

Abstract: An apparatus and method for generating a drive force in a downhole environment includes chambers of a reactant and a catalyst, respectively, that are maintained separate until selectively exposed to one another. Once exposed, the reactant and catalyst produce expanding fluid pressure and sometimes heat. The products of the reaction are directed to a drive member to carry out a desired operation in the downhole environment.

Abstract: A down hole drilling tool for preventing overpressure strain on surface pumping equipment or a down hole drilling motor having a housing and a circulation port and four hydraulic valves positioned on the housing actively working together to effectively open the circulation port to drilling annulus at a high pressure setting and dose the circulation port to annulus at a low pressure setting, the four hydraulic valves include a high pressure setting valve, a low pressure setting valve, a control valve and a fixed setting valve.

Abstract: An impulse-type underground supercharged jet drilling method and device. The impulse-type underground supercharged jet drilling method uses up and down vibrations of a drill string or weight on bit variation during the drilling process, so that an upper joint connected to the drill string drives a housing and a supercharging cylinder block to move up and down relative to a supercharging piston, while the supercharging piston, a high pressure line, and a drive shaft disposed outside the high pressure line make a reciprocally retractable movement relative to the housing. As a result, some working fluid entering the supercharging cylinder block is intermittently supercharged, and discharged from a high pressure fluid passage disposed in the supercharging piston and the high pressure line. The device effectively imparts an underground supercharging to parts of the drilling fluid, thus improving the rock breaking efficiency and the drilling speed.

Abstract: A method, apparatus and system for performing an operation in a borehole is disclosed. A device is disposed in a downhole environment of the borehole to perform the downhole operation. An energy harvesting unit coupled to the device harvests energy from an energy source in a downhole environment of the device and provides the harvested energy to the device to perform the downhole operation.

Abstract: A device is associated with a downhole tool to control the weight that can be set down on the tool while the tool is operating. A shroud is secured to the string that supports the tool with interior modular biasing components that for run in extend the tool past the shroud. Upon encountering a support for the tool, further set down weight compresses the biasing components for a predetermined stroke length delineated by the shroud landing on a support. If the tool is a mill, its operation takes place under the biasing force as the mill advances into the piece being cut or milled under a predetermined pressure. When the mill reaches full extension from the shroud the process can be repeated until the milling is complete. The shroud also centralizes the mill during milling.

Abstract: A system to harvest mechanical energy in a wellbore, wherein the mechanical energy comes from motion. The system uses mechanical energy coming from at least one of: motion of a drill bit, motion of a drill string, motion of flowing air or drilling mud down the drill string to the drill bit and up an annulus between the drill string and the wellbore, motion of a bottom hole assembly connected to the drill string. The system can include a plurality of piezoelectric stand bundles, wherein each individual piezoelectric strand can vibrate as the pressure housing moves in the wellbore, thereby producing electricity.

Abstract: A drilling pressure intensifying device includes a device housing, a device shaft mounted for rotation in the device housing, at least one fluid conduit in the device shaft and a fluid pressure intensifying assembly in the fluid conduit.

Abstract: A pneumatic down-the-hole (DTH) drill having a frame, and a pneumatic percussion piston that moves in a reciprocating manner as pressurized air is fed into the DTH-drill and strikes a tool in the front end of the frame is mounted movably in the longitudinal direction of the frame. A feed channel for feeding compressed air to the DTH-drill shoulders in the frame and in the percussion piston for controlling compressed air to provide an impact movement. In the rear end of the frame the DTH drill has a combustion chamber and an acceleration piston that is arranged to push the percussion piston during the impact movement for a portion of the percussion piston travel, and means for feeding combustion air and fuel into the combustion chamber, whereby the percussion piston is arranged to push the acceleration piston after the impact into the combustion chamber and to compress the air in the combustion chamber prior to feeding the fuel into the combustion chamber.

Abstract: In an aspect, a drilling motor is provided that in one embodiment includes a stator and a rotor configured to be disposed in the stator, wherein the rotor includes a lobe member having an elastically deformable surface configured to provide an interference seal between the stator and the rotor.

Abstract: An apparatus and method for generating a drive force in a downhole environment includes chambers of a reactant and a catalyst, respectively, that are maintained separate until selectively exposed to one another. Once exposed, the reactant and catalyst produce expanding fluid pressure and sometimes heat. The products of the reaction are directed to a drive member to carry out a desired operation in the downhole environment.

Abstract: The rotary percussive device includes a casing forming a support, a striking mechanism equipped with a longitudinal body, rotatably mounted in the casing along the axis of the body, including a cylinder extending along the axis of the body, a striking piston slidingly mounted inside the cylinder and intended to strike a shank coupled to a drill rod, and a distribution device arranged to control an alternating movement of the striking piston along the axis of the body, and a motor arranged to drive the body of the striking mechanism in rotation along an axis of rotation substantially coinciding with the axis of the body. The striking mechanism includes a closing lid mounted on the body and arranged to close one of the ends of the body, the closing lid being coupled in rotation to an output shaft of the motor and at least partially including the distribution device.

Abstract: An apparatus and method for generating a drive force in a downhole environment includes chambers of a reactant and a catalyst, respectively, that are maintained separate until selectively exposed to one another. Once exposed, the reactant and catalyst produce expanding fluid pressure and sometimes heat. The products of the reaction are directed to a drive member to carry out a desired operation in the downhole environment.

Abstract: A pulsing tool for use with a tubular string having a motor unit and a pulsing unit coupled to the motor unit. In one embodiment, the pulsing unit includes a mandrel having an inlet opening and an outlet opening and a flow control bushing, wherein rotation of the mandrel relative to the flow control bushing creates a pressure oscillation which causes movement of the tubular string.

Abstract: An underground drilling method where drilling fluid pulsing down hole tool is combined with a multiple in series pistons down hole tool to provide vigorous vibrations in the drill string and deliver vibrating energy to the drill bit to increase penetration rates and reduce friction between the drill string and the hole. One example method and apparatus shown can operate a simple percussive down hole mud hammer.

Abstract: A generator (10) is provided for positioning downhole in a drill string (12) to generate power powering one or more downhole tools (16). The generator includes a progressive cavity housing (28) and a progressive cavity rotor (30) which rotates in response to fluid passing through the progressive cavity housing. A restriction (36) in the annulus downstream from the ports controls the fluid flow in the annulus and past the restriction, and thereby the fluid flow through the progressive cavity housing. The generator may provide either hydraulic or electrical power, or both, powering the one or more tools.

Abstract: A drilling unit containing a combined pilot bit and reamer. The drilling unit includes a housing containing a mud motor and a pilot bit extending from its distal end. A reamer is mounted to the housing. The mud motor turns the pilot bit while the reamer is turned either by the mud motor or as the drill string is rotated from the surface. The well bore is drilled and reamed in one pass. By positioning the reamer between the pilot bit and the mud motor, the mud motor must only pass through the larger reamer bore rather than the smaller pilot hole. This will allow larger mud motors to be used than would otherwise be possible. In one embodiment, the pilot bit is offset relative to the center of the end of the drill housing, providing increased tangential speed at the point of impact between the pilot bit and formation.

Abstract: A downhole drilling motor beating assembly includes a tubular mandrel adapted to connect to a rotational power output of downhole motor. The bearing assembly includes a mandrel having: an upper end proximal to the downhole motor, a lower end with a pin connection distal from the motor, and a longitudinal passage through the mandrel from the upper end to the lower end. The assembly further includes at least one circumferential ring projecting radially outward from an other surface of the tubular mandrel. The ring has and upper shoulder and a lower shoulder and a radial surface. A circumferential upper thrust bushing contacts the upper shoulder of the ring and a circumferential lower thrust bushing contacts the lower shoulder of the ring. An upper thrust beating contacts the upper thrust bushing and a lower thrust bearing contacts the lower thrust bushing. A tubular bearing housing includes a longitudinal passage from an upper end of the housing to a lower end of the housing.

Abstract: A rechargeable hydraulic accumulator is provided in a wellbore, and a component is actuated by discharging the hydraulic accumulator. The hydraulic accumulator is recharged by increasing pressure in a fluid conduit.

Abstract: The device has a drill body, of generally cylindrical shape, connected by a flexible pipe to a high-pressure water pump placed on a low-height carrying vehicle. A striking piston is mounted movably, and is resiliently returned, in the drill body, and is subjected to a pulsed high water pressure so as to be moved with a percussive movement against a bit-carrying anvil, the pipe simultaneously transmitting to the drill body an alternating rotary movement about its principal axis. A solenoid valve, interposed between the pump and the point of departure of the pipe, receives successive electrical pulses causing opening and closing, which create shock waves in the water column contained in the pipe, which transmits these shock waves to the striking piston of the drill body. Applications: underground workings, mine workings, particularly for use in low-height galleries.

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 fluid distributor device is for a percussive drill assembly including a generally tubular casing (2) having a longitudinal centerline and a piston (6) disposed within the casing so as to define a reservoir chamber (27) in the casing. The distributor device comprises a generally cylindrical body (12) disposed within the casing and including a central axis, two opposing ends spaced apart along the axis, first and second interior chambers and a port fluidly connecting the two chambers. The body further has a plurality of fluid passages extending between the two ends and fluidly connecting the first chamber with the reservoir chamber and a deflectable retainer portion (16) releasably engaged with the casing so as to retain the body at a desired position with respect to the casing centerline. A valve (7) is disposed within the body and is configured to permit fluid flow through the port and to alternatively prevent fluid flow through the port.

Abstract: The present invention discloses, in certain aspects, systems and methods for producing cyclical impacts and, in certain aspects for moving a drilling apparatus for drilling a borehole in a formation, the system in certain embodiments including a housing with a longitudinal axis and a movable member movably disposed therein and movable within the housing transversely to the longitudinal axis of the housing and positioned within the housing with a first space on a first side thereof and a second space on a second side thereof, the movable member substantially fluidly isolating the two spaces and movable to compress gas in one of the first space and the second space while decompressing gas in the other space so that a charge of compressed gas exits from the housing to move an impact member; e.g. for impacting a pile to be driven into the earth or for impacting a drill apparatus for drilling a wellbore, the movable member movable continuously to provide a series of impacts.

Abstract: A power generator for use in a wellbore formed in an earth formation, including an internal combustion engine having a cylinder and a piston defining a combustion chamber in the cylinder, the engine being arranged to induce a reciprocating movement to the piston relative to the cylinder upon combustion of a combustible gas mixture in the combustion chamber, and a linear electricity generator having a stator and a drive shaft. The generator is arranged to generate electricity upon a reciprocating movement of the drive shaft relative to the stator, and the piston is connected to the drive shaft so as to transmit the reciprocating movement of the piston to the drive shaft.

Abstract: An underground drilling method and apparatus generates intense pressure pulses at a location at the surface. The pressure pulses propagate down through a drill string to a drill bit. The pulses may be generated by creating water hammer in flowing drilling mud. Intensity of the acoustic pulses is increased in the bit nozzles. Vigorous pulsing of the fluid exiting the bit nozzles results in better cleaning of the hole bottom and faster drilling. The pulses may be used to drive the operation of various down hole tools. One type of tool has multiple pistons arranged in series. High pressure pulses move the pistons to generate strong mechanical vibration in the drill string. Vibration of the drill string may also reduce the friction between the drill string and the hole, resulting in lower torque requirements.

Abstract: There is provided drilling apparatus (10) comprising a hammer casing (11), a free piston motor piston guide and porting sleeve (12), a drive sub (13), a drill bit (15) splined by shank (16) to the drive sub (13). Below the splined portion (17) the drive sub is relieved at (23) to form an annular air space for motor exhaust air from the splines (16) and (17). The drive sub (13) retains a gauge sleeve (24) via an annular flange (25) between the hammer casing (11) at (26) and a shoulder (27) on the drive sub (13). Below the shoulder (27) the outer diameter of the drive sub (13) is provided with eight grooves that form conduits (30) with the lower portion (31) of the gauge sleeve (24) extending parallel to the drill axis in communication with the space (23) via ports (32). The lower portion (31) extends down the side of the drive sub (13) and terminates with it at (34) adjacent the shoulder (33) at the transition from the bit shank (16) and the bit head (35).

Abstract: Between a drilling motor and the upwardly continuing drill string a housing contains a speed sensor rotationally connected to the motor rotor. Motor speed is sensed and if rotating at a rate less than a selected speed, a cooperating by-pass valve opens to shunt drilling fluid to the well annulus to prevent damage to the stalled motor.

Abstract: A self-contained excavation device, with specific application as a beach umbrella excavator and anchor apparatus, includes a cutting head with a stepped cutting edge to penetrate thin shell layers, recesses defining anchor shelves to prevent pullout from wind, and anchor sweep faces for severing a structural connection between the compacted formation material and the recesses for easy removal of the device. The self-contained excavation device also includes a pressure limit chamber to prevent overpressure of the drilling fluid, a floating piston with straight intake ports for easy maintenance, and a self-cleaning valve to prevent debris from accumulating and clogging the valve.

Abstract: A drill string is equipped with a downhole assembly having an instrumented sub and a drill bit. The instrumented sub has a power source that requires no electrical chemical batter. A mass-spring system is used, which during drilling causes a magnet to oscillate past a coil. This induces current which is used to power downhole instruments.

Abstract: A hydraulic percussion drill includes a piston hammer disposed in a cylinder for reciprocating movement in response to pressure fluid acting continuously on one transverse face of the piston hammer and in response to valving of pressure fluid alternately to an opposed piston face of the piston hammer by a tubular sleeve valve disposed around the piston hammer. The drill includes a percussion bit configured to have a face portion disposed at an acute angle with respect to a plane normal to the bit and the drill central axis. Cooperating spiral splines on the bit and a bit chuck provide for directional drilling using a method which includes causing the bit to receive impact blows without rotating the cylinder housing to initiate a deviated drillhole.

Abstract: A downhole drilling apparatus for interconnection in a casing or liner string having a drill bit disposed thereon for enabling the drilling of intersecting wellbores without removal of the drill bit is disclosed. In a disclosed embodiment, the apparatus comprises a housing having a window. A whipstock is disposed within the housing. Between the window and the whipstock is a filler. The whipstock and the filler define a central bore providing a fluid path through the apparatus. A back pressure valve may be disposed within the central bore to prevent back flow of fluids through the apparatus. Once the total depth of an initial wellbore is reached, the casing or liner string, including the apparatus, may be cemented in place. Thereafter, an intersecting wellbore may be drilled by laterally deflecting a second drill bit with the whipstock through the window of the housing.

Abstract: A downhole drilling apparatus for interconnection in a casing or liner string having a drill bit disposed thereon for enabling the drilling of intersecting wellbores without removal of the drill bit is disclosed. In a disclosed embodiment, the apparatus comprises a housing having a window. A whipstock is disposed within the housing. Between the window and the whipstock is a filler. The whipstock and the filler define a central bore providing a fluid path through the apparatus. A back pressure valve may be disposed within the central bore to prevent back flow of fluids through the apparatus. Once the total depth of an initial wellbore is reached, the casing or liner string, including the apparatus, may be cemented in place. Thereafter, an intersecting wellbore may be drilled by laterally deflecting a second drill bit with the whipstock through the window of the housing.

Abstract: A hydraulic reciprocating piston hammer percussion drill includes an elongated piston hammer having opposed reduced diameter shank portions and disposed in a cylinder for reciprocating movement in response to pressure fluid acting continuously on one transverse face of the piston hammer and in response to valving of pressure fluid alternately to an opposed piston face of the piston hammer by a tubular sleeve valve which is disposed in sleeved relationship around the piston hammer between a piston portion of the piston hammer and an impact blow receiving bit. The tubular sleeve valve is provided with ports which communicate with high pressure and fluid exhaust ports in the piston hammer to effect reciprocation of the sleeve valve and of the piston hammer to deliver repeated impact blows to the bit.

Abstract: A mud pressure intensifier works with existing conventional drill strings without requiring special equipment or drilling fluids. The intensifier is self-contained and is located in the drill string between the drill bit and the rest of the string. The rotational power generated by a conventional mud motor is converted into reciprocal action to reciprocate a piston. The piston elevates the pressure of a portion of the mud on both the upstroke and the downstroke before discharging the pressurized mud at the drill bit.

Abstract: A hydraulic system for supplying hydraulic fluid for operating a mud pulse generator includes an accumulator that has a reservoir. The accumulator is arranged to maintain the fluid pressure in the reservoir. The system also has a pressure operated, one way inlet valve that is arranged to allow hydraulic fluid to be added, under pressure, to the reservoir. The one way inlet valve also includes a valve core.

Abstract: A pressure converter for mounting above the drill bit on a drill pipe for generating a higher fluid pressure in a portion of a drilling fluid flow, comprises a piston moveable in a cylinder. The piston has a large piston area and an opposite small piston area, which provides an increased pressure in a smaller portion of the drilling fluid flow. A valve arrangement controls the drilling fluid flow to and from the cylinder. A high pressure conduit with a check valve connects the space in front of the small piston area to a header conduit for drilling fluid at the increased pressure. The piston also has another large piston area facing oppositely of the first large piston area and being adapted to be influenced by the drilling fluid pressure in the drill pipe so as to move the piston in an opposite direction. Another small piston area facing oppositely of the first small piston area, is adapted to provide an increased drilling fluid pressure upon piston movement in the opposite direction.

Abstract: Pressure converter for mounting above the drill bit at the lower end of a drill pipe for generating a higher fluid pressure in a portion of a drilling fluid flow, including a piston which is moveable in a cylinder. The piston has a large piston area which when moved in a first direction is affected by the pressure of the drilling fluid in the drill pipe, and an opposite small piston area which when moved in the first direction provides an increased pressure in a smaller portion of the drilling fluid flow. A valve arrangement controls the movement of the piston in the cylinder. Conduits communicate with drilling fluid flow passages inside the drill pipe and the annulus outside the drill pipe respectively. The space in front of the small piston area is adapted to receive a particular working fluid and there is provided a moveable membrane so as to separate the working fluid from the drilling fluid.

Abstract: Pressure amplifier mounted at the lower end of a drill pipe for deep drilling to generate an increased fluid pressure. A piston with a pressure stroke and a return stroke between end positions in a cylinder has a large piston area which during the pressure stroke is subjected to the drilling fluid pressure, a first opposite piston area and a second opposite and small piston area which during the pressure stroke generates an increased pressure in a smaller portion of the drilling fluid flow. A valve arrangement controls drilling fluid flows to and from the piston. For each end position of the piston there is provided at least one moveable valve control element which is adapted to be moved by the piston at either end position, in order to activate the valve arrangement.

Abstract: Pressure amplifier for mounting above the drill bit at the lower end of a drill pipe for generating an increased fluid pressure in a drilling fluid flow, for example for obtaining an increased drilling effect. A reciprocating piston in a cylinder is designed with a large piston area at one end (low pressure side), a relatively small piston area at the opposite end (high pressure side), and an annular surface formed at the transition between the two ends. The pressure converter also includes a control valve, an actuator, and a drilling fluid valve to control drilling fluid flow to and from the cylinder.

Abstract: A compressor piston divides a first compartment into two compression chambers, while a hammer piston divides a second compartment into two drive chambers, each of the compression chambers being connected to a respective one of the drive chambers to form a closed fluid system wherein reciprocation of the compressor piston causes cyclic compression and expansion of the fluid in the compression chambers and thus in the drive chambers, to effect a cyclic impacting of the hammer piston with a bit adapter connected to the drill bit. A mud motor rotates a shaft to drive an oscillator which reciprocates the compressor piston. The oscillator can comprise roller elements in the compressor piston in engagement with canted grooves in the shaft. While drilling mud drives the motor and then passes downwardly to flush the drill bit and the borehole, the drilling mud is isolated from the closed fluid system.

Abstract: A rotary fluid converter having sloping exterior shoulders at one end, a hollow bore at the center, and a downwardly sloping fluid orifice extending from said sloping exterior shoulders at a tangent to said interior bore such that turbulence caused by said fluid flow is reduced thereby reducing the erosion and wear of said rotary fluid converter.

Abstract: Converter group comprising at least two pressure converters adapted to be mounted in a row axially above the drill bit at the lower end of a drill pipe for deep drilling, in particular for oil and gas, and for generating an increased fluid pressure utilizing energy in a drilling fluid flow down through the drill pipe, so as to obtain an enhanced drilling effect, preferably by means of one or more high pressure jets adapted to have a cutting action in a surrounding rock formation. Pressure converters (20A, 20B) have axially abutting end faces (22A, 22B) of spherical shape. Attachment means for axial interconnection of the pressure converters are resilient or flexible so as to make possible a certain, small freedom of angular movement between the axes of the pressure converters.

Abstract: A pressure converter for deep drilling keeps contaminated drill mud outside of the working mechanisms of the drill fluid. Thus, the inner drill mechanisms are kept clean by drill fluid. The device contains a rotatable valve positioned above the controlling piston. A tap cover, containing the valve, has two diametrically opposed inlets and two diametrically opposed outlets. The valve has a through passage which is connected to the inlets when the valve is in a second position. Thus, when the piston is operating in a return fashion, the drilling fluid is provided to the area beneath the piston head, keeping this area clean of drill mud.

Abstract: In a percussion drilling apparatus, an impact block assembly is provided for sequentially driving drill rods into a subterranean formation, the impact block assembly including an impact block member aligned with one or more rows of drill rods and a combustion operated piston is arranged above the impact block assembly for sequentially driving each of the impact members downwardly into engagement with the aligned drill rods.

Abstract: A pressure converter for a drill pipe includes a housing with a header channel therein which is in communication with a drill bit, a drive unit which is driven by a driving drilling fluid flow of the drill pipe, a valve which is operatively connected to and moved by the drive unit, a piston which moves in a reciprocating manner thereby creating a pressure stroke and a return stroke, and a check valve through which a portion of the drilling fluid flow is discharged to the drill bit via the header channel.