Embodiments of a downhole drilling assembly generally include a rotatable lower drilling assembly, a rotatable upper drilling assembly, and a drill bit, wherein the upper drilling assembly contains a mud motor adapted for clockwise rotation of its stator and counter-clockwise rotation of its rotor, whereby the lower drilling assembly is rotatable in the opposite direction of the upper drilling assembly or maintainable in a non-rotating state. The apparatus further includes sensors adapted to continuously measure physical properties and/or drilling parameters and a mechanism for continuously transmitting information relating thereto to the surface.

Embodiments of a method for operating a downhole drilling assembly generally include continuously measuring physical properties and/or drilling parameters proximate the drill bit, continuously transmitting information relating thereto to the surface, and controlling rotation of a lower drilling assembly in a non-rotating state or in the opposite direction of an upper drilling assembly by varying drill string rotation.

A directional casing drilling system includes a casing string, a drilling rig and a retrievable Bottom Hole Assembly (BHA). The drilling rig includes a casing drive for rotating the casing string in the borehole, a control system for controlling the casing drive, and a mud pump for pumping a continuous flow of drilling mud into the casing string. The BHA includes a torque transfer section, with which it is secured in the casing string, and a drill bit section held in a drilling position in the torque transfer section. It further includes a mud drive that rotates the drilling position of the drill bit section about the longitudinal axis of the torque transfer section, and a communicating device for communicating the orientation of the drill bit to the control system. The BHA is steered by adjusting the rotational speed of the casing string.

A downhole tool includes a tool body and an actuator coupled to and selectively extendible relative to the tool body. The actuator has a working face that contacts a downhole formation, and which includes an upper portion and a lower portion. The lower portion has a tapered surface that is directed radially inwardly and axially downwardly relative to the first portion, with at least a portion of the tapered surface including an ultrahard material having a different coefficient of friction as compared to a first material of the upper portion.

A drilling system for drilling a borehole. The drilling system may include a drill string, a drill bit coupled to the drill string, a mud motor coupled to the drill string uphole of the drill bit and operable to rotate the drill bit via a driveshaft, a bearing assembly coupled to a downhole end of the mud motor and operable to support the driveshaft, and a rotary steerable system (“RSS”) operable to push the drill bit in a desired direction via pads extended using drilling fluid flowing through the driveshaft and to the RSS. The bearing assembly may include bearings positioned circumferentially around a bore of the bearing assembly, a fluid flowpath through the bearings to allow drilling fluid to pass through the bearings, and a choke assembly positioned in the fluid flowpath and operable to restrict a flow of the drilling fluid through the fluid flowpath.

A method for using a mud motor may comprise drilling a borehole into a formation using a drill string connected to the mud motor and the mud motor is connected to a drill bit, measuring one or more parameters of the mud motor in the borehole, and sending the one or more parameters to surface. A system may comprise a mud motor connected to a drill string, a drill bit connected to the mud motor, a strain gauge, and in information handling system. The strain gauge may be connected to the drill bit and configured to take one or more parameters of the mud motor. The information handling system may be in communication with the strain gauge and configured to record the one or more parameters from the strain gauge.

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.

A method of cleaning a downhole section of a borehole delimited by side walls of a geological formation, the borehole containing a drill pipe having a bottom hole assembly with a drill bit and an electromagnet, and an annulus situated between the side walls and the drill pipe containing cutting debris resulting from drilling. The method comprises deploying a magnetorheological drilling fluid (MR fluid) into the downhole section through the drill pipe, the MR fluid entering the annulus through openings in the bottom hole assembly activating the electromagnet in the bottom hole assembly, the activated electromagnet generating a magnetic field modifies rheological properties of the MR fluid and increasing a transport rate at which cutting debris within the annulus is carried uphole in response to the magnetic field. Methods of providing hole stability and fluid displacement are also disclosed.

A system and method of directionally steering a bottom hole assembly (“BHA”) by receiving data indicative of a directional trend of the BHA and a projection to bit depth; determining a location of the BHA based on the received data; comparing the location of the BHA to a planned drilling path to identify an amount of deviation; automatically creating a modified drilling path based on the amount of deviation and a predicted trend of a downhole parameter; detecting a trend of the downhole parameter while drilling along the modified drilling path; and automatically creating a further modified drilling path when the trend of the downhole parameter is a reversal of the predicted trend of the downhole parameter. The predicted trend of the downhole parameter is an increase of a d-exponent factor or a d-exponent-corrected factor with an increase in depth.

Methods, systems, and apparatus for imparting and limiting hypocycloidal, lateral, and torsional forces onto drill bits are provided, including hypocycloidal bearings for limiting hypocycloidal motion, lateral impulse mechanisms for imparting lateral movement to a drill bit, and torsional impulse mechanisms for imparting torsional movement to a drill bit. The methods systems, and apparatus may decrease friction, increase drilling efficiency, and provide additional benefits to drilling systems.

The disclosure presents apparatuses and systems to reduce drag and friction forces on a drill string located downhole a borehole. The drill string can have two or more movement isolators to allow a movement sensitive tool to be movement isolated from other portions of the drill string that have powered movement. The other drill string portions can be powered by a surface equipment or by a downhole movement motor attached to the drill string, such as a rotational mud motor, an agitator, a jar motor, or a rotary steerable. Portions of the drill string located further downhole than the movement sensitive tool can utilize a movement motor attached to the drill string to provide movement to reduce drag and friction force where the movement isolators can reduce the movement force experienced by the movement sensitive tool.