A drilling tool has an upstream drilling string, a downstream drilling bit, and a percussive device connected between the upstream drilling string and the downstream drilling bit. In a first state, the upstream drilling string is generated with elastic compression by the percussive device, and in a second state, the upstream drilling string releases the elastic compression to apply impacts on the downstream drilling bit through the percussive device. The drilling tool has a prolonged service life and can effectively reduce the drilling cost.

A downhole displacement impact method and an impact drilling tool are provided, which relates to the field of drilling tools. The downhole displacement impact drilling tool includes a flow passing sleeve, a first main shaft, an impact-bearing seat, and a second main shaft that are all formed by annular structures and are connected in sequence from top to bottom. A vibration sleeve, a vibration starting seat, and an impact head are connected in sequence from top to bottom on the impact-bearing seat. The vibration sleeve is connected and fixed to the impact head through a connecting sleeve. The vibration starting seat synchronously rotates with the impact-bearing seat through a spline connection therebetween. The vibration starting seat generates an up-down periodic displacement along an axial direction of the vibration starting seat during rotating.

The systems and techniques described herein may allow for optimized boring through a variety of geologies. A plurality of different boring techniques may be utilized for boring through a geological formation, in order to suit the characteristics of various portions of the geological formation. The systems and techniques described herein includes determining geological features and adjusting operation of boring based on the geological features. In certain such embodiments, boring systems may include a bore head that includes a plurality of boring elements. Such boring elements may be contact and/or non-contact boring elements.

Downhole tractor control systems and methods to adjust a load of a downhole motor to drive one or more wheels of the downhole tractor are disclosed. A method to adjust a load of a downhole motor includes receiving a user input of a desired speed and torque for a plurality of motors, where the plurality of motors powering rotation of wheels of a downhole tractor. The method also includes determining a minimum actual motor speed of the plurality of motors. For at least one motor of the plurality of motors, the method includes determining a power controller output and determining a torque controller output. The method further includes adjusting a voltage source invertor based on a lesser of the power controller output and the torque controller output to modulate voltage provided to the at least one motor.

Downhole tractor control systems and methods to adjust a load of a downhole motor to drive one or more wheels of the downhole tractor are disclosed. A method to adjust a load of a downhole motor includes receiving a user input of a desired speed and torque for a plurality of motors, where the plurality of motors powering rotation of wheels of a downhole tractor. The method also includes determining a minimum actual motor speed of the plurality of motors. For at least one motor of the plurality of motors, the method includes determining a power controller output and determining a torque controller output. The method further includes adjusting a voltage source invertor based on a lesser of the power controller output and the torque controller output to modulate voltage provided to the at least one motor.

A rock-piercing flexible rock drilling robot and a rock breaking method therefor are disclosed. The robot includes a control system, a head, and at least one tail. The head includes a head housing, a propulsion turntable, a drilling mechanism, a hydraulic propulsion system, a first driving mechanism, and a second driving mechanism. The propulsion turntable includes a drill bit located at a center thereof and a cutting turntable arranged around the drill bit. The first driving mechanism is connected to the drill bit, and the second driving mechanism is connected to the cutting turntable. The tail includes a tail housing, an advancing and retreating power system, and a fixed support system. The head and the tail are connected through a flexible component, and the tails are connected through flexible components.

A rock-piercing flexible rock drilling robot and a rock breaking method therefor are disclosed. The robot includes a control system, a head, and at least one tail. The head includes a head housing, a propulsion turntable, a drilling mechanism, a hydraulic propulsion system, a first driving mechanism, and a second driving mechanism. The propulsion turntable includes a drill bit located at a center thereof and a cutting turntable arranged around the drill bit. The first driving mechanism is connected to the drill bit, and the second driving mechanism is connected to the cutting turntable. The tail includes a tail housing, an advancing and retreating power system, and a fixed support system. The head and the tail are connected through a flexible component, and the tails are connected through flexible components.

Downhole tractor control systems and methods to adjust a load of a downhole motor to drive one or more wheels of the downhole tractor are disclosed. A method to adjust a load of a downhole motor includes receiving a user input of a desired speed and torque for a plurality of motors, where the plurality of motors powering rotation of wheels of a downhole tractor. The method also includes determining a minimum actual motor speed of the plurality of motors. For at least one motor of the plurality of motors, the method includes determining a power controller output and determining a torque controller output. The method further includes adjusting a voltage source invertor based on a lesser of the power controller output and the torque controller output to modulate voltage provided to the at least one motor.

Downhole tractor control systems and methods to adjust a load of a downhole motor to drive one or more wheels of the downhole tractor are disclosed. A method to adjust a load of a downhole motor includes receiving a user input of a desired speed and torque for a plurality of motors, where the plurality of motors powering rotation of wheels of a downhole tractor. The method also includes determining a minimum actual motor speed of the plurality of motors. For at least one motor of the plurality of motors, the method includes determining a power controller output and determining a torque controller output. The method further includes adjusting a voltage source invertor based on a lesser of the power controller output and the torque controller output to modulate voltage provided to the at least one motor.

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.