Abstract: A system and method can include a module including at least one actuation assembly configured to transition between an inactive configuration and an active configuration. The system include at least one sensor configured to obtain data that is indicative of an operating parameter, and at least one processor configured to be electronically coupled to the guidance module and the at least one sensor. The at least one processor is configured to, in response to 1) input received from the at least one sensor that is indicative of the measured operating parameter, and 2) received input that is indicative of an actual drilling direction that is deviated from the predetermined drilling direction, adjust an extent that the actuation assembly is in the active configuration.

Abstract: An apparatus and method for damping vibration, especially torsional vibration due to stick-slip, in a drill string, Sensors measure the instantaneous angular velocity of the drill string at one or more locations along the length of the drill string. One or more vibration damping modules are also spaced along the length of the drill string. When torsional vibration above a threshold is detected, the damping module imposes a reverse torque on the drill that dampens the torsional vibration. The reverse torque can be created by imparting a frictional resistance to the rotation of the drill string. The frictional resistance can be created externally, by extending friction pads from the damping module so that they contact the bore hole wall and drag along the bore hole as the drill string rotates, or internally by anchoring a housing mounted on the drill string to the wall of the bore hole and then imposing frictional resistance on a fluid, such as a magnetorheological fluid, flowing within the drill string.

Abstract: A system and method can include a module including at least one actuation assembly configured to transition between an inactive configuration and an active configuration. The system include at least one sensor configured to obtain data that is indicative of an operating parameter, and at least one processor configured to be electronically coupled to the guidance module and the at least one sensor. The at least one processor is configured to, in response to 1) input received from the at least one sensor that is indicative of the measured operating parameter, and 2) received input that is indicative of an actual drilling direction that is deviated from the predetermined drilling direction, adjust an extent that the actuation assembly is in the active configuration.

Abstract: An apparatus for measuring the bending on a drill bit operating down hole in a well may comprise at least three pockets circumferentially spaced equidistantly around the drill collar of the drill string to which the drill bit is attached. Four strain gauges are equidistantly circumferentially spaced around each of the pockets so as to form first and second sets of strain gauges. The strain gauges in the first set are connected into one Wheatstone bridge while the gauges in the second set are connected in a second bridge. Each of the strain gauges that are oriented similarly within each of the pockets are connected in series within a single leg of a bridge so that the output voltage of the bridge is unaffected by bending in the drill string. The output of first bridge is used to determine the bending on the drill bit.

Abstract: An apparatus for measuring the bending on a drill bit operating down hole in a well may comprise at least three pockets circumferentially spaced equidistantly around the drill collar of the drill string to which the drill bit is attached. Four strain gauges are equidistantly circumferentially spaced around each of the pockets so as to form first and second sets of strain gauges. The strain gauges in the first set are connected into one Wheatstone bridge while the gauges in the second set are connected in a second bridge. Each of the strain gauges that are oriented similarly within each of the pockets are connected in series within a single leg of a bridge so that the output voltage of the bridge is unaffected by bending in the drill string. The output of first bridge is used to determine the bending on the drill bit.

Abstract: An apparatus for measuring the bending on a drill bit operating down hole in a well may comprise at least three pockets circumferentially spaced equidistantly around the drill collar of the drill string to which the drill bit is attached. Four strain gauges are equidistantly circumferentially spaced around each of the pockets so as to form first and second sets of strain gauges. The strain gauges in the first set are connected into one Wheatstone bridge while the gauges in the second set are connected in a second bridge. Each of the strain gauges that are oriented similarly within each of the pockets are connected in series within a single leg of a bridge so that the output voltage of the bridge is unaffected by bending in the drill string. The output of first bridge is used to determine the bending on the drill bit.

Abstract: An apparatus and method for damping vibration, especially torsional vibration due to stick-slip, in a drill string, Sensors measure the instantaneous angular velocity of the drill string at one or more locations along the length of the drill string. One or more vibration damping modules are also spaced along the length of the drill string. When torsional vibration above a threshold is detected, the damping module imposes a reverse torque on the drill that dampens the torsional vibration. The reverse torque can be created by imparting a frictional resistance to the rotation of the drill string. The frictional resistance can be created externally, by extending friction pads from the damping module so that they contact the bore hole wall and drag along the bore hole as the drill string rotates, or internally by anchoring a housing mounted on the drill string to the wall of the bore hole and then imposing frictional resistance on a fluid, such as a magnetorheological fluid, flowing within the drill string.

Abstract: An apparatus for measuring the bending on a drill bit operating down hole in a well may comprise at least three pockets circumferentially spaced equidistantly around the drill collar of the drill string to which the drill bit is attached. Four strain gauges are equidistantly circumferentially spaced around each of the pockets so as to form first and second sets of strain gauges. The strain gauges in the first set are connected into one Wheatstone bridge while the gauges in the second set are connected in a second bridge. Each of the strain gauges that are oriented similarly within each of the pockets are connected in series within a single leg of a bridge so that the output voltage of the bridge is unaffected by bending in the drill string. The output of first bridge is used to determine the bending on the drill bit.

Abstract: A preferred embodiment of a system for rotating and guiding a drill bit in an underground bore includes a drilling motor and a drive shaft coupled to drilling motor so that drill bit can be rotated by the drilling motor. The system further includes a guidance module having an actuating arm movable between an extended position wherein the actuating arm can contact a surface of the bore and thereby exert a force on the housing of the guidance module, and a retracted position.

Abstract: Preferred methods and systems generate a control input based on a periodically-varying characteristic associated with the rotation of a drill string. The periodically varying characteristic can be correlated with the magnetic tool face and gravity tool face of a rotating component of the drill string, so that the control input can be used to initiate a response in the rotating component as a function of gravity tool face.

Abstract: A preferred embodiment of a system for rotating and guiding a drill bit in an underground bore includes a drilling motor and a drive shaft coupled to drilling motor so that drill bit can be rotated by the drilling motor. The system further includes a guidance module having an actuating arm movable between an extended position wherein the actuating arm can contact a surface of the bore and thereby exert a force on the housing of the guidance module, and a retracted position.

Abstract: A preferred embodiment of a system for rotating and guiding a drill bit in an underground bore includes a drilling motor and a drive shaft coupled to drilling motor so that drill bit can be rotated by the drilling motor. The system further includes a guidance module having an actuating arm movable between an extended position wherein the actuating arm can contact a surface of the bore and thereby exert a force on the housing of the guidance module, and a retracted position.

Abstract: An extending arm is incorporated into a formation evaluation MWD collar or sub for extending outwardly from the tool and maintaining direct and continuous contact with the borehole wall (e.g., formation). In accordance with this invention, a method is presented for intermittently deploying the extendable arm and thereby decreasing drilling interference (caused by the arm) and avoiding the damage caused by accidents involving a nuclear source.

Abstract: A method and apparatus for establishing a remote communications link from the rig floor to the downhole MWD system is presented. In accordance with the present invention, the state of a physical condition downhole is changed in a predetermined timed sequence. This state change is controlled on the surface at the drilling platform and detected downhole by the MWD system. The desired operating mode of the MWD system is then determined based on the detected time sequence of the state changes. Preferred embodiments of the present invention utilize two different state changes which are detectable downhole and which can be controlled at the surface. In a first embodiment, the state changes comprise a preselected timed sequence of powering the MWD system up or down. This power cycling is accomplished by operating the mud pump in an ON/OFF sequence which will cause the MWD turbine to similarly be powered up or down.

Abstract: A method and apparatus is presented for measuring the azimuth angle of a borehole being drilled, the data for determining the azimuth angle being obtained while the drillstring is rotating.

Abstract: A method is presented for measuring the azimuth angle of a borehole being drilled, the data for determining the azimuth angle being obtained while the drillstring is rotating.

Abstract: A method is presented, for use in borehole drilling, for correcting errors in azimuth determination resulting from variations in the earth's magnetic field to which a measuring instrument is exposed. The method distinguishes between variations in the earth's magnetic field caused by the drillstring and variation caused by external sources, and the method corrects only for errors caused by the drillstring. If the error is caused by the drillstring, an azimuth correction is made based on dip angle data, thereby reducing errors caused by scale factor variations since dip angle is a ratio quantity of magnetic field components.

Abstract: A method is presented for evaluation of formation invasion and formation permeability by conducting a series of formation resistivity loggings in the operation of a measurement while drilling (MWD) logging system.

Abstract: In an MWD measurement system, the speed of rotation of a downhole turbine is measured by the interaction of a triaxial magnetometer in a sensor package and a permanent magnet attached to the turbine shaft. The triaxial magnetometer may be part of an existing MWD system for measuring borehole directional parameters. The magnet is a strong magnet mounted on the turbine shaft perpendicular to the axis of the turbine and the axis of the drill string.