A method, system, and computer-readable medium related to control of mud motors in drilling systems, of which the method includes measuring an eccentricity of rotation of a rotor in a stator of a mud motor using a rotor-position sensor, determining a torque of the mud motor based in part on the eccentricity, and selecting a fluid flow rate, a pressure, or both of fluid delivered downhole, through the mud motor, based in part on the determined torque.

A method, system, and computer-readable medium related to control of mud motors in drilling systems, of which the method includes measuring an eccentricity of rotation of a rotor in a stator of a mud motor using a rotor-position sensor, determining a torque of the mud motor based in part on the eccentricity, and selecting a fluid flow rate, a pressure, or both of fluid delivered downhole, through the mud motor, based in part on the determined torque.

A construction machine for special civil engineering, includes a leader on which an advancing carriage is guided, which carriage has a holder for a work device, in particular a drilling implement or pile-driving implement, and which carriage is connected with a first drive, by way of which it can be moved along the leader. An additional auxiliary carriage is arranged on the leader, which carriage can be moved along the leader by way of a second drive, wherein at least one actuator and/or at least one sensor is/are arranged on the auxiliary carriage.

A back-up wrench device of a top drive assembly of a drilling rig comprises a gripper device operable to grip an end of a drill pipe, and at least one fluid actuator operable to compensate for thread travel during makeup or breakout operations. The back-up wrench device can comprise a first housing coupled to the gripper device and a second housing coupled to a support structure of the top drive assembly, and can comprise a primary hydraulic housing movably coupled to the first and second housings. The at least one fluid actuator can include upper and lower fluid actuators each movable through upper and lower fluid chambers of the primary hydraulic housing during respective makeup and breakout operations to compensate for thread travel. Associated systems and methods for thread compensation with the back-up wrench are provided.

A back-up wrench device of a top drive assembly of a drilling rig comprises a gripper device operable to grip an end of a drill pipe, and at least one fluid actuator operable to compensate for thread travel during makeup or breakout operations. The back-up wrench device can comprise a first housing coupled to the gripper device and a second housing coupled to a support structure of the top drive assembly, and can comprise a primary hydraulic housing movably coupled to the first and second housings. The at least one fluid actuator can include upper and lower fluid actuators each movable through upper and lower fluid chambers of the primary hydraulic housing during respective makeup and breakout operations to compensate for thread travel. Associated systems and methods for thread compensation with the back-up wrench are provided.

A cutting head has a mounting bracket for attachment to a pipe and a cutter wheel. A double tapered bearing is connected between the mounting bracket and the cutter wheel. The bearing allows the cutter wheel to be rotated without rotation of the pipe. A drive shaft connector on the cutter wheel is connectable to a pilot hole drive shaft for rotating the cutter wheel and pulling it and the pipe. A pilot hole is drilled in a conventional manner. The pipe is attached to the mounting bracket and an end of the pilot hole drive shaft is then connected to the cutter wheel. Simultaneously the pilot hole is enlarged and the pipe and cutter wheel are pulled along the enlarged hole by the drive shaft. The cutter wheel advances along the pilot hole and the pipe is simultaneously advanced through the enlarged hole immediately behind the cutter wheel.

A cutting head has a mounting bracket for attachment to a pipe and a cutter wheel. A double tapered bearing is connected between the mounting bracket and the cutter wheel. The bearing allows the cutter wheel to be rotated without rotation of the pipe. A drive shaft connector on the cutter wheel is connectable to a pilot hole drive shaft for rotating the cutter wheel and pulling it and the pipe. A pilot hole is drilled in a conventional manner. The pipe is attached to the mounting bracket and an end of the pilot hole drive shaft is then connected to the cutter wheel. Simultaneously the pilot hole is enlarged and the pipe and cutter wheel are pulled along the enlarged hole by the drive shaft. The cutter wheel advances along the pilot hole and the pipe is simultaneously advanced through the enlarged hole immediately behind the cutter wheel.

An apparatus for use in maintaining a desired orientation of an implement is provided. The apparatus includes orientation sensing equipment operable to sense the orientation of the implement, and an orientation indicator operable to be mounted relative to the implement, the orientation indicator having a plurality of indication portions, and when the orientation indicator is mounted relative to the implement, the indication portions are positioned so as to be visible from different locations around the implement. In use, when the orientation of the implement deviates from the desired orientation, one or more indication portions provide a visible indication of a direction in which the implement has deviated from the desired orientation.

An apparatus for use in maintaining a desired orientation of an implement is provided. The apparatus includes orientation sensing equipment operable to sense the orientation of the implement, and an orientation indicator operable to be mounted relative to the implement, the orientation indicator having a plurality of indication portions, and when the orientation indicator is mounted relative to the implement, the indication portions are positioned so as to be visible from different locations around the implement. In use, when the orientation of the implement deviates from the desired orientation, one or more indication portions provide a visible indication of a direction in which the implement has deviated from the desired orientation.

A single-pass type drilling machine includes a guide tower, a string of drilling rods, an extension element having an upper end and a lower end with the lower end being coupled with an upper end of the string of drilling rods, a rotary head slidably coupled with the guide tower, and a detection system. The rotary head and the extension element are mutually slidable and arranged to couple with each other in an upper end stop position, where the rotary head is coupled with the extension element substantially at the upper end of the extension element. The rotary head is coupled with the extension element at a lower position with respect to the upper end stop position in at least one locking position. The detection system detects the reaching of the at least one locking position by detecting at least the mutual axial position of the extension element and the rotary head.