Abstract: A method of transmitting pressure pulses from a downhole location through a flowing fluid in a wellbore comprises using a linear actuator to controllably move a reciprocating member axially back and forth between a first position and a second position to at least partially obstruct flow of the flowing fluid to generate the pressure pulses. A reciprocating pulser for generating pressure pulses in a fluid flowing in a wellbore, comprises a fluid passage that allows flow of the fluid through the pulser, and a reciprocating member. A linear actuator is coupled to the reciprocating member, such that the linear actuator moves the reciprocating member in a first axial direction and then in a reverse direction to at least partially obstruct flow of the fluid through the pulser to generate pressure pulses in the flowing fluid.

Abstract: A reciprocating pulser system for generating pressure fluctuations in a flowing drilling fluid comprising a reciprocating poppet and a stationary valve assembly with axial flow passages. The poppet reciprocates in close proximity to the valve assembly, at least partially blocking the flow through the valve assembly and generating oscillating pressure pulses. The poppet passes through two zero speed positions during each cycle, enabling rapid changes in signal phase, frequency, and/or amplitude thereby facilitating enhanced data encoding. The poppet is driven by a linear electric motor disposed in a lubricant filled housing. In one embodiment, the housing to shaft seal is a flexible bellows. In one embodiment, a force balance spring is used to essentially offset the hydraulic flow forces on the poppet. In one embodiment, a bypass poppet is used to adjust the differential pressure across the valve assembly.

Abstract: A downhole device processes particles entrained in a drilling fluid returning up a wellbore. In one embodiment, the device includes a housing having at least one cutting surface formed in a chamber of a housing. A cutting head disposed in the chamber crushes or comminutes the particles entrained in the drilling fluid to a predetermined size. The device is disposed in the wellbore and processes the entrained particles before they enter a selected wellbore device such as a pump. In certain embodiments, the housing has at least two chambers, wherein the entrained particles are reduced to a first predetermined size in the first chamber, a second predetermined size in the second chamber, etc. Also, the housing can include an operator that generates an energy field that reduces the size of the particles entrained in the drilling fluid to a first predetermined size when the particles flow through the energy field.

Abstract: An anti-plugging 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 data encoding. The rotor is driven by a electric motor disposed in a lubricant filled housing. In one embodiment, the housing to shaft seal is a flexible bellows. 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 torsion spring may be a solid torsion bar or a magnetic spring.

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: An anti-plugging 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 data encoding. The rotor is driven by a electric motor disposed in a lubricant filled housing. In one embodiment, the housing to shaft seal is a flexible bellows. 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 torsion spring may be a solid torsion bar or a magnetic spring.

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 system is presented for detecting downhole generated telemetry pressure pulses in a well. The system employs high sensitivity dynamic pressure sensors such as hydrophones for detecting the pulses in either the surface drilling fluid supply line or in the fluid return annulus. The high sensitivity allows detection of smaller surface pulses than standard transducers. In one embodiment, an annular pulser is used to generate pulses directly in the annulus.

Abstract: A reciprocating pulser system for generating pressure fluctuations in a flowing drilling fluid comprising a reciprocating poppet and a stationary valve assembly with axial flow passages. The poppet reciprocates in close proximity to the valve assembly, at least partially blocking the flow through the valve assembly and generating oscillating pressure pulses. The poppet passes through two zero speed positions during each cycle, enabling rapid changes in signal phase, frequency, and/or amplitude thereby facilitating enhanced data encoding. The poppet is driven by a linear electric motor disposed in a lubricant filled housing. In one embodiment, the housing to shaft seal is a flexible bellows. In one embodiment, a force balance spring is used to essentially offset the hydraulic flow forces on the poppet. In one embodiment, a bypass poppet is used to adjust the differential pressure across the valve assembly.

Abstract: An anti-plugging 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 data encoding. The rotor is driven by a electric motor disposed in a lubricant filled housing. In one embodiment, the housing to shaft seal is a flexible bellows. 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 torsion spring may be a solid torsion bar or a magnetic spring.

Abstract: The present invention provides apparatus for power transfer over a nonconductive gap between rotating and non-rotating members of downhole oilfield tools. The gap may contain a non-conductive fluid, such as drilling fluid or oil for operating hydraulic devices in the downhole tool. The downhole tool, in one embodiment, is a drilling assembly wherein a drive shaft is rotated by a downhole motor to rotate the drill bit attached to the bottom end of the drive shaft. A substantially non-rotating sleeve around the drive shaft includes a plurality of independently operated force application members used to exert the force required to maintain and/or alter the drilling direction. In the preferred system, one or more mechanically operated devices such as hydraulic units control the force application members. A transfer device transfers electrical power between the rotating and non-rotating members, and the electric power is converted directly to mechanical power.