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 shaft enlargement arrangement for a boring system is provided, the shaft enlargement arrangement comprising a hollow column proximate a lower end of the boring system; a first cutter head that is rotatably fitted to the hollow column, with first drive means being provided to rotate the first cutter head relative to the hollow column so as to bore downwardly a hole having a diameter corresponding substantially to the diameter of the first cutter head; and a boring head arrangement fitted to an operatively lower end of the column, the boring head arrangement terminating in a second cutter head to bore a leading hole as the boring system proceeds to bore downwardly. In an embodiment, the first cutter head comprises a support body carrying a winged arrangement, the support body being rotatably fitted to the column, the winged arrangement comprising a plurality of wings extending from the support body, each wing being fitted with, or comprising, a plurality of first cutter elements.

The present application discloses a pipeline radar and television inspection robot which includes a robot body, a directional drilling lifting device, a directional drilling rotary device, a directional drilling swing device, a radar, cameras and a driving apparatus; wherein the directional drilling lifting device is on a front part of the robot body; the directional drilling rotary device is on the directional drilling lifting device; the directional drilling swing device is on the directional drilling rotary device; the radar and the cameras are on the directional drilling swing device; the driving apparatus are on a bottom of the robot body. The directional drilling lifting device, the radar and the cameras are plugged in the robot body. The robot body electrically connects to cables which electrically connect to a control system. The cameras and the radar are able to be adjusted and the components are connected as modules.

The present application discloses a pipeline radar and television inspection robot which includes a robot body, a directional drilling lifting device, a directional drilling rotary device, a directional drilling swing device, a radar, cameras and a driving apparatus; wherein the directional drilling lifting device is on a front part of the robot body; the directional drilling rotary device is on the directional drilling lifting device; the directional drilling swing device is on the directional drilling rotary device; the radar and the cameras are on the directional drilling swing device; the driving apparatus are on a bottom of the robot body. The directional drilling lifting device, the radar and the cameras are plugged in the robot body. The robot body electrically connects to cables which electrically connect to a control system. The cameras and the radar are able to be adjusted and the components are connected as modules.

A drilling speed-enhancing device has an outer cylinder; a rotary main shaft arranged in an inner chamber of the outer cylinder and configured to rotate around its own axis; an output main shaft arranged below the rotary main shaft and configured to be driven by the rotary main shaft to rotate around its own axis, a lower end of the output main shaft extending out of the inner chamber of the outer cylinder for connecting with a drilling bit of a dual-drive drilling tool; and a percussion generator arranged between the output main shaft and the outer cylinder. The percussion generator can drive the outer cylinder and the rotary main shaft to move upward relative to the output main shaft, so that under action of WOB, the rotary main shaft and the outer cylinder move downward to generate impact on the output main shaft.

A drilling speed-enhancing device has an outer cylinder; a rotary main shaft arranged in an inner chamber of the outer cylinder and configured to rotate around its own axis; an output main shaft arranged below the rotary main shaft and configured to be driven by the rotary main shaft to rotate around its own axis, a lower end of the output main shaft extending out of the inner chamber of the outer cylinder for connecting with a drilling bit of a dual-drive drilling tool; and a percussion generator arranged between the output main shaft and the outer cylinder. The percussion generator can drive the outer cylinder and the rotary main shaft to move upward relative to the output main shaft, so that under action of WOB, the rotary main shaft and the outer cylinder move downward to generate impact on the output main shaft.

A speed-enhancing drilling tool includes an upstream drill string (10), which has a drive motor and a first driving rod coupled therewith, a downstream drilling bit; and a percussive device connected between the upstream drilling string and the downstream drilling bit. The first driving rod extending axially and the drive motor are configured to drive the first driving rod in rotation. The percussive device has a rotary driving part having an upper end engaged with the first driving rod to rotate together therewith; and a rotary working part having an upper end engaged with a lower end of the rotary driving part and a lower end connected with the downstream drilling bit. The rotary working part can be driven by the rotary driving part to rotate about its axis, and axially movable relative thereto; and a percussion generating part arranged around the rotary working part.

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.

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.

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.