Abstract: A drilling apparatus includes a housing that defines a longitudinal axis. A power section of the apparatus includes rotor adapted to move with eccentric rotary motion with respect to the longitudinal axis in response to the passage of drilling fluids through the power section. A power transmission shaft has an upper end coupled to the rotor and movable with the eccentric motion of the rotor, and a lower end constrained to rotate in a concentric manner with respect to the longitudinal axis. A generally rigid torsion rod has upper and lower ends constrained to rotate in a concentric manner, and the upper end of the torsion rod is coupled to the lower end of the power transmission shaft. A mandrel including a connection for a drill bit is interconnected with the lower end of the torsion rod such that a torque may be transmitted from the torsion rod to the mandrel to drive a drill bit.

Abstract: A bearing assembly for use in a down-hole drilling apparatus includes a bearing housing configured for connection to a drill string and a mandrel disposed at least partially within the bearing housing. The mandrel is configured to rotate about a longitudinal axis extending therethrough. A hybrid thrust bearing package is provided and disposed radially between the bearing housing and the mandrel. The hybrid thrust bearing package includes a plurality of ball bearings movable through at least one race, an annular stator supported by the bearing housing and an annular rotor ring supported on and rotatable with the mandrel. The annular stator and rotor rings define first and second flat PDC bearing surfaces engaged with one another at a bearing interface oriented generally orthogonally with respect to the longitudinal axis.

Abstract: A method for calculating orientation changes within a borehole using a gyro sensor to detect angular deflection rates in an attitude reference interval as a MWD system is moved from a first to a second location within the borehole. A compass shot may be taken at one or more of the first and second locations using a magnetometer and accelerometer or gyro sensor and accelerometer. Tieback and/or overlap processing may be applied to increase the accuracy of measured orientation within the borehole. Additionally, tieback and/or overlap processing may be applied to adjust sensor model parameters in response to discrepancies between calculated and measured locations. Iterated calculations of orientation change between subsequent intervals may allow MWD orientation to be computed for an entire drilling operation using only a single compass shot.

Abstract: A method to determine the earth's magnetic field vector along a sub-surface wellpath having unknown and possibly changing azimuth, in the presence of a magnetic disturbance caused by a magnetic source external to the wellpath includes estimating the three components of the earth field along the three axes of a magnetic sensor package by a polynomial function of measured depth along the wellpath. Upon removal of the earth's magnetic field from the measurements, the resultant magnetic field of the disturbance is determined and can be used to determine the position and orientation of the source of the disturbance.

Abstract: An apparatus for use in a horizontal section of a drill string is disclosed. The apparatus includes a motor that is connected to the horizontal section of the drill string. The motor is adapted to impart vibrations in the horizontal section of the drill string, where the vibrations are at about the lateral resonant frequency of the horizontal section of the drill string.

Abstract: Downhole magnetic measurement devices and methods are provided for estimation of magnetic fields during drilling. In certain embodiments, a triaxial vector magnetometer is provided and affixed to a drill string subassembly. While the drill string subassembly is rotating, as during drilling operations, an average total magnetic field value (BTwR) is determined as an average of the instantaneous vector magnitudes of the three measured orthogonal component magnetic fields. In this way, near-bit estimates of the downhole magnetic field may be obtained and used for a variety of functions. These downhole magnetic measurement devices may be useful determining magnetic fields, and estimating borehole inclination and azimuth of drill string subassemblies during drilling operations. Additionally, downhole magnetic measurement devices may be used for detecting the presence and distance to external ferromagnetic materials.

Abstract: A bearing assembly includes a first race having a first set recesses disposed on an upper surface thereof. Wherein a first set of bearing elements are disposed within the first set of recesses and the first set of bearing elements extend upwardly from the first set of recesses at an inclination relative to a vertical axis of the first race. A second race having a second set of recesses disposed on an upper surface thereof. A second set of bearing elements are disposed within the second set of recesses and the second set of bearing elements extend upwardly from the second set of recesses at an inclination relative to a vertical axis of the second race.

Abstract: An apparatus and a method for generating electrical power are disclosed. The apparatus includes a mud motor including a rotor. The rotor is capable of eccentric motion and has a rotor end. The apparatus further includes an inverse magnetostrictive device having a magnetostrictive element. The magnetostrictive element has a flexing end that is affixed to the rotor end.

Abstract: The present disclosure is directed to an antenna for transfer of information along a drill string. The antenna has an antenna coil having a long side and short side. The antenna coil is adapted to be affixed to the drill string such that the long side of the antenna coil is along the longitudinal axis of the drill string, and the short side is perpendicular to the longitudinal axis of the drill string.

Abstract: The present invention concerns application of a unique conductive electrode geometry used to form an efficient wideband, one- or two-way wireless data link between autonomous systems separated by some distance along a bore hole drill string. One objective is the establishment of an efficient, high bandwidth communication link between such separated systems, using a unique electrode configuration that also aids in maintaining a physically robust drill string. Insulated or floating electrodes of various selected geometries provide a means for sustaining or maintaining a modulated electric potential adapted for injecting modulated electrical current into the surrounding sub-surface medium. Such modulated current conveys information to the systems located along the drill string by establishing a potential across a receiving insulated or floating electrode.

Abstract: The present invention concerns application of a unique conductive electrode geometry used to form an efficient wideband, one- or two-way wireless data link between autonomous systems separated by some distance along a bore hole drill string. One objective is the establishment of an efficient, high bandwidth communication link between such separated systems, using a unique electrode configuration that also aids in maintaining a physically robust drill string. Insulated or floating electrodes of various selected geometries provide a means for sustaining or maintaining a modulated electric potential adapted for injecting modulated electrical current into the surrounding sub-surface medium. Such modulated current conveys information to the systems located along the drill string by establishing a potential across a receiving insulated or floating electrode.

Abstract: A downhole drilling apparatus for measure while drilling including a housing defining a longitudinal housing axis, wherein the housing has an upper end and a lower end. A motor includes a rotor, wherein the rotor is adapted to be driven by drilling fluids. A first drive coupling is coupled between the rotor and a first driven rod. A second drive coupling is coupled between the driven rod an a connecting shaft. A third drive coupling is coupled between the connecting shaft and a second driven rod. A fourth drive coupling is coupled between the second driven rod and a motor bearing section, wherein the connecting shaft extends through an offset bore in the housing and transmits power from the motor to the drill bit.

Abstract: A housing including longitudinally extending tubular members interconnected to allow controlled relative bending thereof, during a drilling operation, a rotary drive transmitting torsion bar extending generally longitudinally within the housing to controllably bend in response to relative bending of said members, a rotary drill bit operatively connected to said torsion bar to be rotated as the bar rotates, a rotary drive operatively connected to the torsion bar to rotate the bar, means for controlling relative bending of the said members during torsion bar rotation and as a function of such rotation.

Abstract: The present invention concerns application of a unique conductive electrode geometry used to form an efficient wideband, one- or two-way wireless data link between autonomous systems separated by some distance along a bore hole drill string. One objective is the establishment of an efficient, high bandwidth communication link between such separated systems, using a unique electrode configuration that also aids in maintaining a physically robust drill string. Insulated or floating electrodes of various selected geometries provide a means for sustaining or maintaining a modulated electric potential adapted for injecting modulated electrical current into the surrounding sub-surface medium. Such modulated current conveys information to the systems located along the drill string by establishing a potential across a receiving insulated or floating electrode.

Abstract: Pressure pulses in a flowing stream are generated by movement radially of an elastomer membrane surrounding a perforated tube. Movement outward of the membrane is initiated by closing of a pilot valve in the tube, but is accelerated by pressure increases from decreasing flow area around the membrane. Opening of the pilot valve allows the membrane to return to its collapsed condition. Selection of flow area around the expanded membrane allows selection of pulse amplitude. Signals from a variety of downhole instruments are provided to a driver of the pilot valve, so that pressure pulses from operation of the membrane can be detected uphole in a well.