Abstract: A mud pulse telemetry system comprises a surface located fluid supply line having a drilling fluid flowing therein. A non-venting pulser is disposed in the drilling fluid in the supply line, and the non-venting pulser is adapted to generate pressure fluctuations in the flowing drilling fluid. A downhole receiver in hydraulic communication with the non-venting pulser is adapted to detect the pressure fluctuations in the drilling fluid. A method for transmitting pressure signals from a surface location to a downhole location in a wellbore, comprises disposing a non-venting pulser in a surface located fluid supply line having a drilling fluid flowing therein. The non-venting pulser is actuated to generate pressure fluctuations in the flowing drilling fluid according to a predetermined encoding scheme. The pressure fluctuations are detected with a downhole receiver in hydraulic communication with the non-venting pulser.

Abstract: The invention relates to a system and method for wireless data transmission in an open process regime, for example a producing (or injecting) well associated with oil and gas production, the system comprising means for data acquisition, means for en data conversion, means for wireless data transmission, control means, power source, and a static pulse generation device adapted for generating static pressure fluctuations in the well fluid. The data conversion means are adapted to convert data to a simplified number format to be transmitted by the induced fluctuations in the process fluid.

Abstract: The invention relates to a method for localizing a drilling device of an earth drilling apparatus, wherein a localization signal is emitted by the drilling device, said signal being received by an external receiver and evaluated for determining the position of the drilling device, wherein an output signal, which is converted into the localization signal, is fed to the drilling device via a connection line, which is connected to the drilling device.

Abstract: A drill string component includes a box-end and a pin-end. Each end includes a signal transceiver, which are operably coupled together. Each signal transceiver communicates with another signal transceiver in another component to form a communication network in the drillstring. An end-cap may be placed in the central bore of the pin-end of a component to form an annular chamber between a side of the end-cap and a wall of the central bore of the pin-end when the end-cap is disposed in the central bore. In some embodiments, an electronics module may be placed in the annular chamber and configured to communicate with one of the signal transceivers. Accelerometer data, as well as other sensor data, at various locations along the drillstring may be sampled by the electronics module and communicated to a remote computer. Drillstring motion dynamics, such as vibration, may be determined based on the accelerometer data.

Abstract: A downhole telemetry system for use in a wellbore including borehole fluid. The system includes a stator including flow channels though the stator and a rotor including flow channels though the rotor. The rotor is rotatable on a drive shaft by the force of the borehole fluid flowing through the rotor. The rotation of the rotor creates pressure variations in the borehole fluid related to the movement of the rotor channels relative to the stator channels, thus forming a carrier wave. A regulating system adjusts the amount of fluid force on the rotor for a given flow rate of borehole fluid to maintain the frequency of the carrier wave within a range of a target frequency. Also, an alternator drivable by the rotation of the drive shaft provides power to the system. The system also includes an encoder capable of adjusting the rotation of the rotor to modulate the carrier wave.

Abstract: A system and method are provided for providing electromagnetic (EM) measurement-while-drilling (MWD) telemetry capabilities using an existing mud-pulse MWD tool. An EM tool intercepts the output from the mud-pulse tool and generates an EM signal that mimics a mud-pulse pressure signal. The EM signal is intercepted at the surface by a receiver module that conditions the signal and inputs the signal into the existing pulse tool receiver. Since the EM signal mimics a mud-pulse signal, the pulse tool receiver does not require software or hardware modifications in order to process an EM telemetry mode. The EM tool can be adapted to also provide dual telemetry by incorporating a conventional pressure pulser that would normally be used with the pulse tool.

Abstract: Disclosed are a system, device, and method for generating pulse signals that correlate to geological information in a wellbore. The system and method comprises a pulse generating device longitudinally and axially positioned within an annular drill collar flow channel such that the drilling fluid flows through the annular drill collar flow channel and the drilling fluid is guided into two sets of selectively reversible flow, upper and lower flow connecting channels, wherein the connecting channels are connected to an inner flow channel and the annular drill collar flow channel, and wherein the annular drill collar flow channel is acted upon by one or more flow throttling devices thereby transmitting signals. The device utilizes a turbine residing near and within proximity of a flow diverter that diverts drilling mud into and away from turbine blades such that the force of the drilling mud causes the turbine blades and the turbine to rotationally spin around a coil assembly.

Abstract: A managed bulk drilling system that employs a guide wire for ranging and crosswell telemetry. Some system embodiments include multiple drilling assemblies operating in the vicinity of a reference well that contains an electrical cable. The electrical cable is coupled to a surface control system. The control system uses the electrical cable as part of an antenna to receive uplink signals from the drilling assemblies and to broadcast down-link signals to the drilling assemblies. The uplink signals can include position data and the downlink signals can include individual steering commands to adjust the trajectories of each drilling assembly. The cable can also generate a guidance field for the drilling assemblies to detect and follow.

Abstract: A system for communicating between a first location and a second location comprises a jointed tubular string having a first section and a second section connected at a connection joint, with the tubular string having a fluid in an internal passage thereof. A first acoustic transducer is mounted in the internal passage of the first section proximate the connection joint, and a second acoustic transducer is mounted in the internal passage of the second section proximate the connection joint. A signal transmitted from the first location to the second location is transmitted across the connection joint as an acoustic signal in the fluid from the first acoustic transducer to the second acoustic transducer.

Abstract: A logging tool has three seismic sensors that generate seismic signals in response to microseismic events and can be a Triaxial Borehole Seismic system. The tool also has additional sensors, such as a wireline tension measuring circuit, a gamma ray sensor, an inclinometer, and a gyroscope. The tool deploys downhole with a multi-conductor (i.e., seven conductor) wireline. For the seismic signals, a telemetry unit on the tool derives frequency-modulated carrier signals from the seismic signals, and a transformer of the unit transmits these carrier signals to surface acquisition equipment using cross-wired pairs of conductors in the wireline connected to the transformer's terminals. For the signals from the other sensors, the telemetry unit derives analog carrier signals from their signals and transmits the analog carrier signals to the surface acquisition equipment using remaining conductors of the wireline.

Abstract: Systems and methods for reliably communicating data between surface and downhole equipment over a power cable, regardless of the length of the power cable, wherein a transmitter modulates a common data stream onto multiple high frequency carrier signals, each of which has a different frequency. Each of the different frequencies is best suited to communication over a different length of cable. The resulting modulated high frequency data signals are impressed on the power cable and are recovered from the cable by a receiver. The receiver is configured to recover signals at each of the different carrier frequencies, at least one of which should be transmitted with little enough attenuation and interference that the data stream can be accurately recovered from the corresponding modulated high frequency data signal.

Abstract: Exemplary systems and methods are directed to transmission of electromagnetic (EM) pulses in a downhole environment, which is located below a surface of a landform. A sequence of EM energy pulses is generated from a signal generator located at the surface of the landform. The energy pulses are reflected at a ring frequency by one or more downhole transducers. The reflected energy pulse is received at a receiver, which is located at the surface, during a predetermined time interval. The receiver detects the received energy pulses through a time domain or frequency domain technique. The detected ring frequency is correlated to a parameter or condition of the downhole environment.

Abstract: A method of signal processing includes providing at least a first pressure sensor and a second pressure sensor spaced in a drilling system and using an algorithm to separate the downwardly propagating waves from the upwardly propagating waves. In one or more examples, an algorithm may include determining a velocity of pressure signals in a wellbore, time-shifting and stacking pressure signals from at least the first pressure sensor and the second pressure sensor to determine a downwardly propagating noise signal, and subtracting the downwardly propagating noise signal from at least the signal from the first pressure sensor.

Abstract: Apparatus and methods for establishing electrical communication between an instrument subsection disposed below a mud motor and an electronics sonde disposed above the mud motor in a drill string conveyed borehole logging system. Electrical communication is established via at least one conductor disposed within the mud motor and connecting the instrument sub section to a link disposed between the mud motor and the electronics sonde. The link can be embodied as a current coupling link, a magnetic coupling ling, an electromagnetic telemetry ling and a direct electrical contact link. Two way data transfer is established in all link embodiments. Power transfer is also established in all but the electromagnetic telemetry link.

Abstract: To characterize an electrical cable that is deployed in a well, a voltage input is applied to the electrical cable at an earth surface location, where the well extends from the earth surface location. A current response resulting from the voltage input is measured at the earth surface location. At least one parameter of the electrical cable is computed according to the measured current response.

Abstract: A subsurface formation monitoring system and method is described. The system includes a conductive piping structure positionable within a borehole extending into a subsurface formation. The conductive piping structure is electrically decoupled from a production tubing by an insulating packer. The system also includes a downhole installed conductive casing sub that has one or more sensors. The conductive casing sub is electrically coupled to the conductive piping structure. The system further includes a surface installed power and communication module that has an alternate current generator. The power and communication module is electrically coupled to the conductive piping structure via a downhole intermediate module. The alternate current generator can inject a current signal that flows downhole to the conductive casing sub and then returns with sensor measurements to the surface power and communication module via a grounded return electrode that is coupled to the subsurface formation.

Abstract: The present invention is directed towards methods of oil and gas well logging, monitoring, and the field of electrically powering submersible devices like electrical motors in oil and gas wells.

Abstract: Measurements made with at least two sensors (flow rate or pressure) during generation of a message concurrently with operation of a noise source are used to estimate a channel transfer function. The estimated transfer function is then used to attenuate pump noise in a mud pulse telemetry system. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: An acoustic telemetry apparatus and method for communicating encoded digital data from a down-hole location through a borehole to the surface is described including an acoustic channel terminated at a down-hole end by a reflecting terminal (133, 134), an acoustic wave generator (140) located at the surface and providing an acoustic wave carrier signal through said acoustic, channel, a modulator (162, 163) located down-hole to modulate amplitude and/or phase of said carrier wave in response to an encoded digital signal and one or more sensors (150) located at the surface adapted to detect amplitude and/or phase related information of acoustic waves traveling within said acoustic channel to determine the encoded digital data.

Abstract: An acoustic telemetry apparatus and methods for communicating digital data from a down-hole location through a borehole to the surface or between locations within the borehole are described including a receiver and a transmitter linked by an acoustic channel (210) wherein acoustic channel has a cross-sectional area of 58 cm2 or less and the transmitter comprises an electro-active transducer generating a modulated continuous waveform.

Abstract: A mud pulser creates pressure pulses in a stream of drilling fluid circulating through a drill string. The pulser has a body connected into the drill string, and defines a flow passage for drilling fluid. A signal poppet having a piston is reciprocally carried within the body. A lower end of the poppet selectively restricts flow of drilling fluid through an orifice and to thereby increase pressure and creates a pulse while in an extended position. An inner passage with an upward facing servo seat formed therein is located in the body and extends through the signal poppet for the passage of drilling fluid. A motor-driven servo valve selectively engages the servo seat to control flow of drilling fluid through the inner passage. A limit switch responds to axial movement of the servo valve cause the motor to turn off when the servo valve reaches predetermined axial positions.

Abstract: The present invention provides a method and system in which signals from the surface are sent by changing flow rate of the drilling fluid supplied to the drill string during drilling of a wellbore. The signals are sent based on a fixed or dynamic time period schemes so that the sent signals cross a dynamic threshold value in a known manner. A controller downhole sets the dynamic threshold and determines the number of times a parameter, such as voltage, relating to the changes in the flow rate crosses the set dynamic threshold. Based on the number of the number of crossings and/or the number of crossings and the timing of such crossings, the controller ascertains the signal sent from the surface for use downhole.

Abstract: Downhole electrical power generation apparatus and methods of using stored pressurized gas and/or ambient downhole pressure. One example comprises first and second fluid receiving chambers, a fluid communication path for allowing flow of fluid from the first chamber via the fluid communication path to the second chamber and a turbine generator disposed so that fluid flowing from the first chamber via the fluid communications path to the second chamber operates the turbine generator to generate electrical power.

Abstract: A downhole system (10) comprises a tool (16) suspended on a reelable support (18). The support (18) has an optical fibre and the tool communicates with a surface controller via the fibre. The tool (16) has a number of units (24,16a,16b,16c), the unit (24) functioning as a router to transmit and receive signals to and from the other units (16a,16b,16c) and the surface controller via the optical fibre. Each of the units (24,16a,16b,16c) is assigned a unique address which permits secure communication between each unit (24,16a,16b,16c) and the controller over the fibre.

Abstract: A transmission system in a downhole component comprises a plurality of data transmission elements. A coaxial cable having an inner conductor and an outer conductor is disposed within a passage in the downhole component such that at least one capacitor is disposed in the passage and having a first terminal coupled to the inner conductor and a second terminal coupled to the outer conductor. Preferably the transmission element comprises an electrically conducting coil. Preferably, within the passage a connector is adapted to electrically connect the inner conductor of the coaxial cable and the lead wire. The coaxial capacitor may be disposed between and in electrically communication with the connector and the passage. In another embodiment a connector is adapted to electrical connect a first and a second portion of the inner conductor of the coaxial cable and a coaxial capacitor is in electrical communication with the connector and the passage.

Abstract: Well for production of hydrocarbons, comprising a hole drilled down into an underground, a casing fastened to the hole wall, a production pipe that extends into the casing from the surface and down to a hydrocarbon-containing zone, a hanger on the surface in an upper end of the well, in which hanger the production pipe and casing are hung up and electrically short-circuited, and a packer arranged sealingly and electrically short-circuiting in the annulus between the production pipe and the casing, in or close to a lower end of the well, distinguished in that the well further comprises: a primary coil arranged concentrically about the production pipe, a secondary coil arranged concentrically about the production pipe, a load connected to the secondary coil, and an alternating current generator/signal unit connected to the primary coil.

Abstract: A pressure release encoding system for communicating downhole information through a wellbore to a surface location include a downhole tool with a valve for providing a fluid restriction to fluid passing in the wellbore, a sensor positioned in the wellbore for sensing a downhole condition in the wellbore, a brake cooperative with the valve for moving the valve between at least two positions in timed relation to the downhole condition sensed by the sensor, and a detector positioned at the surface location for providing a measurement value at the surface location correlative to the time between the changes of the pressure of the fluid in the wellbore. The system associates position of the valve with pressure transduction. The sensor is an inclination sensor for sensing an angle of inclination of the wellbore.

Abstract: A gap collar for an electromagnetic communication unit of a downhole tool positioned in a wellbore is provided. The downhole tool communicates with a surface unit via an electromagnetic field generated by the electromagnetic communication unit. The gap collar includes a first collar having a first end connector and a second collar having a second end connector matingly connectable to the first end connector. The gap collar further includes a non-conductive insulation coating disposed on the first and/or second end connectors, and a non-conductive insulation molding positioned about an inner and/or outer surface of the collars. The insulation molding moldingly conforms to the shape collars. The connectors are provided with mated threads modified to receive the insulation coating. Measurements taken by the downhole tool may be stored in memory, and transmitted to the surface unit via the electromagnetic field.

Abstract: The present disclosure relates to a telemetry tool for use in a well. The telemetry tool has a hollow, conductive waveguide through which a non-conductive fluid can flow. A transmitter and a receiver are disposed in the hollow interior of the waveguide, separated by some desired distance. A signal is transmitted by the transmitter, propagated by the waveguide, and received by the receiver.

Abstract: This invention applies to the means whereby capacitance changes due to varying temperature and/or pressure in a piezoelectric transducer used for acoustic telemetry in a drilling environment is dynamically offset by modifying one or more parameters associated with the drive or control circuitry of said transducer. The object of the invention is to closely maintain the transducer in a resonant mode, thereby ensuring optimum energy consumption.

Abstract: A hybrid telemetry system for passing signals between a surface control unit and a downhole tool is provided. The downhole tool is deployed via a drill string into a wellbore penetrating a subterranean formation. The hybrid telemetry system includes an uphole connector, a downhole connector, and a cable operatively connecting the uphole and downhole connectors. The uphole connector is operatively connectable to a drill string telemetry system for communication therewith. The downhole connector is operatively connectable to the downhole tool for communication therewith.

Abstract: Aspects of the inventions generally provide a method and apparatus for coupling a communication sub to a wired drill pipe. In one aspect, a surface of a coupler head is non threaded and configured to provide a retaining force. In another aspect, a coupler head is coupled to a body, and a support mechanism is coupled to the body and configured to secure the coupler head within a receiving end of the wired drill pipe. In another aspect, a method of placing a communication sub involves inserting the communication sub into the receiving end of the wired drill pipe, adjusting the position of the communication sub until an indication of signal communication between the communication sub and the wired drill pipe is observed, and after the indication of signal communication is observed, retaining the communication sub within the receiving end until removal of the communication sub is desired.

Abstract: A subsea data and power transmission apparatus includes primary and secondary open magnetic circuits with coils for wireless data and power transfer between a drilling tool and a drilling rig. The primary magnetic circuit is U-shaped and the secondary is O-shaped. Both magnetic systems are electrically insulated. The electrical signal and power are transferred from one magnetic circuit to another through an air or water gap between the magnetic circuits. The U-shaped and O-shaped magnetic circuits allow communication and power transfer remotely with no mechanical or electrical connectors.

Abstract: Interconnection device for electronic circuits, notably microwave electronic circuits, characterized in that it comprises at least one transmission line coupled to an earth line, the two lines being made on a face of a dielectric substrate, at least one metallization surface forming on the other face of the dielectric substrate at least one coupling element disposed on a surface substantially equal in area to the surface occupied by the transmission line and the earth line, the interconnection being carried out substantially at the level of the ends of the transmission line and of the earth line.

Abstract: An oscillating shear valve system for generating pressure fluctuations in a flowing drilling fluid comprising a stationary stator and an oscillating rotor, both with axial flow passages. The rotor oscillates in close proximity to the stator, at least partially blocking the flow through the stator and generating oscillating pressure pulses. The rotor passes through two zero speed positions during each cycle, facilitating rapid changes in signal phase, frequency, and/or amplitude facilitating enhanced, multivalent data encoding. The rotor is driven by a motorized gear drive. In one embodiment, a torsional spring is attached to the motor and the resulting spring mass system is designed to be near resonance at the desired pulse frequency. The system enables the use of multivalent encoding schemes for increasing data rates.

Abstract: A long distance power transfer coupler for wellbore applications system uses two or more wireless modules, each wireless module comprises a self-resonant coil, to transmit energy within a wellbore. The second, and potentially subsequent, wireless modules receive radiant electromagnetic energy from a nearby neighbor which the self-resonant coil converts to usable electromagnetic energy which may be used for power, data communications, or a combination thereof. A first module may be deployed at a predetermined position in the wellbore; a cable attached to a second length of tubing; and one or more second modules attached to the tubing and coupled inductively to a resistive load. The tubing and second module or modules are deployed downhole and electromagnetic energy transmitted wirelessly between the first module and the second module. Modules may be deployed in a completion string.

Abstract: Data retrieval tags, drillstring communications systems and methods, and computer programs are disclosed. The data retrieval tag includes an insulator substrate, at least one analog memory cell disposed on the insulator substrate and an antenna coupled to the analog memory.

Abstract: In some embodiments, an apparatus [100] and a system, as well as a method and an article, may operate to transmit downhole data in a drilling fluid via fluid pressure modulation, and receive the downhole data at a fluid pulse receiver included in a conduit [104] coupled to a drill pipe downstream from a Kelly hose. Other apparatus, systems, and methods are disclosed.

Abstract: Subterranean oilfield sensor systems and methods are provided. The subterranean oilfield sensor systems and methods facilitate downhole monitoring and high data transmission rates with power provided to at least one downhole device by a light source at the surface. In one embodiment, a system includes uphole light source, a downhole sensor, a photonic power converter at the downhole sensor, an optical fiber extending between the uphole light source and the photonic power converter, and downhole sensor electronics powered by the photonic power converter. The photonic power converter is contained in a high temperature resistant package. For example, the high temperature resistant package and photonic power converter may operate at temperatures of greater than approximately 100° C.

Abstract: A telemetry tool is placed in a drill string adjacent to a drill bit. The telemetry tool includes position and direction sensors, a power supply, a signal receiver and a signal emitter. An external base unit, may be mounted on the surface at some distance from the wellhead. The external base unit generates, and transmits into the geological formation, a carrier signal. The carrier signal may be a DC carrier signal, and it may be a variable DC signal. The base unit also has a receiving unit, which may have the opposite DC voltage to that of the carrier signalemitting unit. The geological formation provides a large current path between the carrier current generating unit and the downhole end of the drill string. The carrier current, or some portion thereof, is received at the telemetry unit. The drill string defines a relatively low resistance conductor for the return signal.

Abstract: A downhole telemetry system (10) disposed within a wellbore (32). The downhole telemetry system (10) includes a downhole transmitter (48) operable to optically transmit a data stream and a downhole receiver (52) operable to receive the optically transmitted data stream. An optically transmissive fluid (64) is disposed in the wellbore (32) and provides a medium for the optical transmission of the data stream between the downhole transmitter (48) and the downhole receiver (52).

Abstract: A wireless communication and drill string telemetry system. The communication system is used for communicating information along a drill string between a boring tool and a boring machine. An insulator assembly provides an electrically insulated gap between the drill string communication path and a soil engaging electrode for the electrical return path. A transmitter assembly includes a data transmitter for encoding and transmitting a data signal. A signal coupler couples the data signal to the drill string and provides a controlled electrical connection between the drill string communication path and the soil engaging electrode. The signal coupler comprises a transformer and a current regulating circuit to adjust a voltage across the transformer's primary winding. A receiver assembly is disposed proximate the drilling machine and includes a toroidal pickup coil and a signal processing assembly.

Abstract: A pressure release encoding system for communicating downhole information through a wellbore to a surface location has a valve for providing a fluid restriction to fluid passing in the wellbore, a sensor positioned in the wellbore for sensing a downhole condition in the wellbore, an actuator cooperative with the valve for moving the valve between at least two positions in timed relation to the downhole condition sensed by the sensor, and a detector positioned at the surface location for providing a measurement value at the surface location correlative to the time between the changes of the pressure of the fluid in the wellbore. The sensor is an inclination sensor for sensing an angle of inclination of a drill bit in the wellbore.

Abstract: A downhole telemetry system for use in a wellbore including borehole fluid. The system includes a stator including flow channels though the stator and a rotor including flow channels though the rotor. The rotor is rotatable on a drive shaft by the force of the borehole fluid flowing through the rotor. The rotation of the rotor creates pressure variations in the borehole fluid related to the movement of the rotor channels relative to the stator channels, thus forming a carrier wave. A regulating system adjusts the amount of fluid force on the rotor for a given flow rate of borehole fluid to maintain the frequency of the carrier wave within a range of a target frequency. Also, an alternator drivable by the rotation of the drive shaft provides power to the system. The system also includes an encoder capable of adjusting the rotation of the rotor to modulate the carrier wave.

Abstract: An electromagnetic well borehole telemetry system for transmitting information between a downhole transceiver, disposed preferably within a borehole assembly in the borehole, and a surface transceiver positioned at or near the surface of the earth. A trigger and cooperating strobe are used to define strobe increments. Synchronous telemetry measurements made during the strobe increments are algebraically summed to identify a synchronous cyclical noise component in a composite electromagnetic telemetry signal. Any non cyclical noise components occurring during the strobe increments algebraically cancel in the algebraic summing operation. The cyclical noise component is then removed from the composite signal thereby increasing the signal to noise ratio of the telemetry system. The system is particularly effective in minimizing electromagnetic noise generated by the rotation of a rotating element such as the rotary table or top drive of a drilling rig.

Abstract: A system for optimizing a mud-pulse telemetry system, the system including: a plurality of sensors distributed along a drill string adapted for being disposed in a borehole, each sensor configured to perform a measurement of a characteristic of at least one of mud in a column within the borehole and a mud-pulse telemetry signal propagating in the mud; and a processing unit for receiving the measurements, the processing unit comprising an algorithm to compile a data set from the measurements and to determine a parameter of the mud-pulse telemetry system using the data set to optimize the mud-pulse telemetry system. A method and a computer program product are also provided.

Abstract: A logging tool has three seismic sensors that generate seismic signals in response to microseismic events and can be a Triaxial Borehole Seismic system. The tool also has additional sensors, such as a wireline tension measuring circuit, a gamma ray sensor, an inclinometer, and a gyroscope. The tool deploys downhole with a multi-conductor (i.e., seven conductor) wireline. For the seismic signals, a telemetry unit on the tool derives frequency-modulated carrier signals from the seismic signals, and a transformer of the unit transmits these carrier signals to surface acquisition equipment using cross-wired pairs of conductors in the wireline connected to the transformer's terminals. For the signals from the other sensors, the telemetry unit derives analog carrier signals from their signals and transmits the analog carrier signals to the surface acquisition equipment using remaining conductors of the wireline.

Abstract: An improved energy efficient intelligent pulser driver used for generating a mud pulse in a MWD (measurement while drilling) application. In the pulser driver, a direct current (DC) powered control circuit activates a three-phase DC brushless motor that operates a servo-valve. Opening of the servo-valve equalizes pressure in a plenum causing the operation of a main valve reducing flow area and causing a pressure spike in the mud column. Closing of the servo-valve creates a reduction in mud pressure that operates the main valve and increases the flow area causing an end to the pressure spike. The servo-valve is powered both in opening and closing operations by the motor.

Abstract: A telemetry system involving a shear-type mud pulser valve as the preferred embodiment is described. The control system includes a motor driver for the mud pulser which, in essence, moves one movable plate with respect to a stationary plate to create openings of various sizes. Pressure is sensed uphole of the pulser valve and is compared in real time to the desired pressure pulse amplitude. By allowing different relative rotational positions of the rotatable plate with respect to the stationary plate, different amplitudes can be achieved to further enhance the transmission of data to the surface. The control system compensates for wear in the mud pulser valve itself as well as drastic changes in mud flow and pressure. The configuration is simple and not prone to fouling from grit or other particles in the mud.

Abstract: An apparatus for use in drilling or producing from a well bore, the apparatus comprising a downhole member such as a drilling device or a production device which is capable of being attached to a tubular such as a drill string, production string or the like, means for rotating a tubular, control means for controlling the rotation of said tubular in order to transmit information along said tubular and means for monitoring the rotation of said tubular and for decoding said information transmitted along said tubular such that a magnitude of a parameter can be determined by the drilling member from the rotation or said tubular. The invention also relates to a method for communicating with a downhole tool using the apparatus.