Abstract: A rotary valve can include a housing, a manifold with multiple flow paths can be fixedly mounted to the housing. A rotary actuator with a first surface can be rotatably mounted within the housing, and a valve seat with a second surface can be fixedly attached to the manifold, where the second surface can sealingly engage the first surface. The rotary actuator can include a gap that selectively aligns with respective ones of valve seat ports as the rotary actuator rotates relative to the valve seat, thereby selectively pressurizing one or more actuators. A system and method can include a rotary valve that selectively causes pads to extend at a predetermined orientation in the wellbore to steer a drill bit. The azimuthal orientation of a rotary actuator of the valve can determine which pads are extended and which are retracted as the drill bit rotates.

Abstract: According to aspects of the present disclosure, systems and methods for a closed-loop speed/position control mechanism. An example system may include a housing and a planetary gearbox disposed within the housing, wherein a ring gear of the planetary gearbox is coupled to the housing, a sun gear of the planetary gearbox is coupled to a drive shaft, and a planetary carrier of the planetary gearbox is coupled to an output shaft. A controller may receive measurements from sensors proximate to the output shaft and use those measurements to transmit control signals to change the rotation of the drive shaft. In this way, the output shaft may be rotated independently of the housing by controlling the rotation of the drive shaft. In example systems, the output shaft may be a sonde or an offset mandrel coupled to a drill bit. The rive shaft may be coupled to a fluid-controlled controlled drive mechanism and rotation may be controlled by adjusting flow control valve.

Abstract: A rotary valve can include a housing, a manifold with multiple flow paths can be fixedly mounted to the housing. A rotary actuator with a first surface can be rotatably mounted within the housing, and a valve seat with a second surface can be fixedly attached to the manifold, where the second surface can sealingly engage the first surface. The rotary actuator can include a gap that selectively aligns with respective ones of valve seat ports as the rotary actuator rotates relative to the valve seat, thereby selectively pressurizing one or more actuators. A system and method can include a rotary valve that selectively causes pads to extend at a predetermined orientation in the wellbore to steer a drill bit. The azimuthal orientation of a rotary actuator of the valve can determine which pads are extended and which are retracted as the drill bit rotates.

Abstract: A downhole tool including multiple orifices defining at least a first and a second flow path, and a valve that adjusts to change a ratio of fluid flow between the first and second flow paths, the valve being offset from the multiple orifices by a gap that is adjustable to customize a sensitivity of the change to each adjustment. A method for regulating flow along a first fluid path in a downhole tool includes adjusting a valve relative to multiple orifices that define the first fluid path and a second fluid path, said adjusting changing a ratio of fluid flow between the first and second flow paths, and adjusting a gap between the valve and the multiple orifices to modify a sensitivity of the change to each adjustment.

Abstract: A rotary valve can include a housing, a manifold with multiple flow paths can be fixedly mounted to the housing. A rotary actuator with a first surface can be rotatably mounted within the housing, and a valve seat with a second surface can be fixedly attached to the manifold, where the second surface can sealingly engage the first surface. The rotary actuator can include a gap that selectively aligns with respective ones of valve seat ports as the rotary actuator rotates relative to the valve seat, thereby selectively pressurizing one or more actuators. A system and method can include a rotary valve that selectively causes pads to extend at a predetermined orientation in the wellbore to steer a drill bit. The azimuthal orientation of a rotary actuator of the valve can determine which pads are extended and which are retracted as the drill bit rotates.

Abstract: A Rotary Steerable System (RSS) includes a flexible collar coupled therein that reduces the stiffness of the RSS and permits a tighter turning radius to be achieved. The positioning of the flexible collar between the steering section and the controller of the RSS further improves the turning radius, and may permit a push-the-bit system to operate similar to a point-the bit system. The flexible collar permits communication therethrough between controller and the steering sections of the RSS. The RSS may be arranged as a modular system to receive various configurations of a flexible collar and may operate with no flexible collar installed. The modularity enables tuning of the stiffness of an RSS to achieve different steering objectives.

Abstract: An example method for control of a drilling assembly includes receiving measurement data from at least one sensor coupled to an element of the drilling assembly positioned in a formation. An operating constraint for at least a portion of the drilling assembly may be determined based, at least in part, on a model of the formation and a set of offset data. A control signal may be generated to alter one or more drilling parameters of the drilling assembly based, at least in part, on the measurement data and the operating constraint. The control signal may be transmitted to a controllable element of the drilling assembly.

Abstract: Systems and methods of down-hole power generation are disclosed, which provide for the generation of electrical power in a down-hole environment for use by down-hole tools such as logging tools, telemetry, and electric control circuit. The electrical generator is operably coupled to a turbine shaft of a hydraulic turbine, and operates at a first rotational speed in response to a rotation of the turbine shaft. The turbine shaft is also coupled to a down-hole actuator such as a rotary drill bit such that the actuator operates at a second rotational speed in response to the rotation of the turbine shaft. A gearbox is operably coupled between the actuator and the turbine shaft to permit operation of the generator and actuator at different rotational speeds by the rotation of the turbines shaft.

Abstract: A rotary steerable drilling tool and a method according to which a universal joint is sealed. In one embodiment, the method includes providing the collar, the shaft, the universal joint, and first and second shoulders between which the universal joint is positioned; providing first and second self-energizing seals between the collar and the shaft on opposite sides of the universal joint; rotating the collar and the shaft; seating the first self-energizing seal against the first shoulder; and seating a second self-energizing seal against the second shoulder. In one embodiment, the universal joint includes a convex surface formed on the shaft; a first concave surface extending circumferentially about the shaft and adapted to mate with the convex surface to carry a first axial load; and a spacer ring defining a second concave surface adapted to mate with the convex surface to carry a second axial load.

Abstract: A rotary valve can include a housing, a manifold with multiple flow paths can be fixedly mounted to the housing. A rotary actuator with a first surface can be rotatably mounted within the housing, and a valve seat with a second surface can be fixedly attached to the manifold, where the second surface can sealingly engage the first surface. The rotary actuator can include a gap that selectively aligns with respective ones of valve seat ports as the rotary actuator rotates relative to the valve seat, thereby selectively pressurizing one or more actuators. A system and method can include a rotary valve that selectively causes pads to extend at a predetermined orientation in the wellbore to steer a drill bit. The azimuthal orientation of a rotary actuator of the valve can determine which pads are extended and which are retracted as the drill bit rotates.

Abstract: A Rotary Steerable System (RSS) includes a flexible collar coupled therein that reduces the stiffness of the RSS and permits a tighter turning radius to be achieved. The positioning of the flexible collar between the steering section and the controller of the RSS further improves the turning radius, and may permit a push-the-bit system to operate similar to a point-the bit system. The flexible collar permits communication therethrough between controller and the steering sections of the RSS. The RSS may be arranged as a modular system to receive various configurations of a flexible collar and may operate with no flexible collar installed. The modularity enables tuning of the stiffness of an RSS to achieve different steering objectives.

Abstract: According to aspects of the present disclosure, systems and methods for controlling the speed of a fluid-controlled drive mechanism are described herein. An example system may include a housing, a variable flow fluid pathway disposed within the housing, an electromagnet coupled to the housing, a fluid-controlled drive mechanism in fluid communication with the variable flow fluid pathway, and a load-generating assembly coupled to the fluid-controlled drive mechanism. An example method may include altering a variable flow fluid pathway disposed within a housing, wherein the variable flow fluid pathway is in fluid communication with a fluid-controlled drive mechanism, and generating an electrical current through an electromagnet, wherein the electromagnet is coupled to the housing.

Abstract: According to aspects of the present disclosure, systems and methods for controlling the direction of a drilling assembly within a borehole are described herein. An example system may include a housing 201 b (FIG. 2B) and a variable flow fluid pathway 203 (FIG. 2B) within the housing 201b. A fluid-controlled drive mechanism 209 (FIG. 2C) may be in fluid communication with the variable flow fluid pathway 203. Additionally, an offset mandrel 212 may be coupled to an output of the fluid-controlled drive mechanism 209. The offset mandrel 212 may be independently rotatable with respect to the housing 201b. The system may also include a bit shaft 216 pivotably coupled to the housing 201b and coupled to an eccentric receptacle of the offset mandrel 212.

Abstract: Systems and methods of down-hole power generation are disclosed, which provide for the generation of electrical power in a down-hole environment for use by down-hole tools such as logging tools, telemetry, and electric control circuit. The electrical generator is operably coupled to a turbine shaft of a hydraulic turbine, and operates at a first rotational speed in response to a rotation of the turbine shaft. The turbine shaft is also coupled to a down-hole actuator such as a rotary drill bit such that the actuator operates at a second rotational speed in response to the rotation of the turbine shaft. A gearbox is operably coupled between the actuator and the turbine shaft to permit operation of the generator and actuator at different rotational speeds by the rotation of the turbines shaft.

Abstract: A downhole tool including multiple orifices defining at least a first and a second flow path, and a valve that adjusts to change a ratio of fluid flow between the first and second flow paths, the valve being offset from the multiple orifices by a gap that is adjustable to customize a sensitivity of the change to each adjustment. A method for regulating flow along a first fluid path in a downhole tool includes adjusting a valve relative to multiple orifices that define the first fluid path and a second fluid path, said adjusting changing a ratio of fluid flow between the first and second flow paths, and adjusting a gap between the valve and the multiple orifices to modify a sensitivity of the change to each adjustment.

Abstract: A rotary steerable drilling tool and a method according to which a universal joint is sealed. In one embodiment, the method includes providing the collar, the shaft, the universal joint, and first and second shoulders between which the universal joint is positioned; providing first and second self-energizing seals between the collar and the shaft on opposite sides of the universal joint; rotating the collar and the shaft; seating the first self-energizing seal against the first shoulder; and seating a second self-energizing seal against the second shoulder. In one embodiment, the universal joint includes a convex surface formed on the shaft; a first concave surface extending circumferentially about the shaft and adapted to mate with the convex surface to carry a first axial load; and a spacer ring defining a second concave surface adapted to mate with the convex surface to carry a second axial load.

Abstract: A well tool can include a well tool housing and a cooling section positioned within the well tool housing, the cooling section including a helical cooling fluid flow path, and the flow path having a reversal of direction proximate an end of the cooling section. Another well tool can include a cooling fluid which flows through the helical flow path toward the end of the cooling section in one direction, and which flows through the helical flow path away from the end of the cooling section in an opposite direction. Another well tool can include the cooling fluid which flows through the helical flow path, and which makes multiple passes longitudinally through the cooling section proximate a heat-sensitive device.

Abstract: A method and system for steering a rotary steerable tool in a borehole. A method includes rotating a deflection sleeve about a steerable shaft. A deflection ramp is aligned to deflect the shaft in a predetermined direction by the rotating. The deflection sleeve is axially displaced along the steerable shaft. The steerable shaft is deflected by the displacing.

Abstract: An example downhole apparatus includes a drive shaft with a longitudinal axis, a spherical portion that extends radially from the longitudinal axis, and first and second interfacial surfaces proximate the spherical portion. An outer housing is positioned at least partially around the spherical portion. A radial bearing may be between the spherical portion and the outer housing and coupled to the outer housing. The radial bearing may comprise first and second interfacial surfaces in contact with the respective first and second interfacial surfaces of the drive shaft to transmit or receive torque in corresponding first and second rotational directions. A first axial bearing is coupled to the outer housing and in contact with a first end of the spherical portion to axially secure the drive shaft with respect to the outer housing.

Abstract: According to aspects of the present disclosure, systems and methods for a closed-loop speed/position control mechanism. An example system may include a housing and a planetary gearbox disposed within the housing, wherein a ring gear of the planetary gearbox is coupled to the housing, a sun gear of the planetary gearbox is coupled to a drive shaft, and a planetary carrier of the planetary gearbox is coupled to an output shaft. A controller may receive measurements from sensors proximate to the output shaft and use those measurements to transmit control signals to change the rotation of the drive shaft. In this way, the output shaft may be rotated independently of the housing by controlling the rotation of the drive shaft. In example systems, the output shaft may be a sonde or an offset mandrel coupled to a drill bit. The rive shaft may be coupled to a fluid-controlled controlled drive mechanism and rotation may be controlled by adjusting flow control valve.