A rotary actuator assembly can include a fluid motor with a rotor that displaces with hypocyclic precessional motion within a stator in response to fluid flow through the fluid motor, and a gear reducer section including an input gear that is fixed relative to the rotor and displaces with the hypocyclic precessional motion relative to an output gear. Another rotary actuator assembly can include a fluid motor with a rotor having a central longitudinal axis that rotates about a central longitudinal axis of a stator, and a gear reducer section including an input gear that rotates with the rotor and displaces relative to an output gear, and the input gear having the same central longitudinal axis as the rotor. A well system can include at least two fluid motors, and fluid flow through one fluid motor causes rotation of the other fluid motor in the well.

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.

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.

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.

An apparatus includes a tool body having a bore that is aligned with a lengthwise axis and a rotating assembly coupled to the tool body. The rotating assembly includes a turbine wheel that is disposed adjacent to an inner surface of the wall and exposed to the bore. The rotating assembly includes an impeller that is disposed adjacent to an outer surface of the wall in a position corresponding to the turbine wheel. Each of the turbine wheel and impeller has a respective axis of rotation that is transverse to the lengthwise axis. The rotating assembly includes a link rod that couples the turbine wheel to the impeller and is used to transfer mechanical energy generated by the turbine wheel to the impeller. The apparatus is operable by fluid flow through a drill string to increase pressure in a wellbore annulus and enhance transportation of formation cuttings up the annulus.

An apparatus includes a tool body having a bore that is aligned with a lengthwise axis and a rotating assembly coupled to the tool body. The rotating assembly includes a turbine wheel that is disposed adjacent to an inner surface of the wall and exposed to the bore. The rotating assembly includes an impeller that is disposed adjacent to an outer surface of the wall in a position corresponding to the turbine wheel. Each of the turbine wheel and impeller has a respective axis of rotation that is transverse to the lengthwise axis. The rotating assembly includes a link rod that couples the turbine wheel to the impeller and is used to transfer mechanical energy generated by the turbine wheel to the impeller. The apparatus is operable by fluid flow through a drill string to increase pressure in a wellbore annulus and enhance transportation of formation cuttings up the annulus.

In light of increasingly severe and diverse excavation conditions for hydrocarbon resource recovery, such as the drilling of very deep wells, provided is a highly impact-resistant polyglycolic acid resin composition that is resistant to damage even from contact or collision with various members during molding, transport, and well drilling; has excellent mechanical properties and heat resistance; can easily be removed as necessary after the completion of well treatment; and contributes to reducing the cost and shortening the process of well drilling. Also, provided is a molded product for well drilling, such as a downhole tool member.

A wellbore assembly is provided that can include a first motor housing assembly member and a second motor housing assembly member that can bend relative to the first motor housing assembly at a bend location. The assembly can also include a strain gauge positioned on a first side of the bend location to determine an amount of bend of the second motor housing assembly member relative to the first motor housing assembly member by determining a strain. Based on the strain, the amount of bend or bend direction of the second motor housing assembly member relative to the first motor housing assembly member can be determined.

A wellbore assembly is provided that can include a first motor housing assembly member and a second motor housing assembly member that can bend relative to the first motor housing assembly at a bend location. The assembly can also include a strain gauge positioned on a first side of the bend location to determine an amount of bend of the second motor housing assembly member relative to the first motor housing assembly member by determining a strain. Based on the strain, the amount of bend or bend direction of the second motor housing assembly member relative to the first motor housing assembly member can be determined.