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 downhole device and method to trigger, shift, and/or operate a downhole device of a drilling string in a wellbore is disclosed. At a high level, the disclosed device causes a portion of drilling fluids to bypass the drill bit and into the annulus. The bypass may be triggered upon certain conditions related to the rotation speeds of the drill string or other conditions such as the pressure of the drilling fluids. For example, the drill string may be rotated in some protocol of operation (e.g., stop at certain rpm, and/or stop at certain other rpm) to describe a recognizable series of signals to an accelerometer and/or microprocessor that will communicate to pumps or valves to operate or pause/stop operations.

A downhole device and method to trigger, shift, and/or operate a downhole device of a drilling string in a wellbore is disclosed. At a high level, the disclosed device causes a portion of drilling fluids to bypass the drill bit and into the annulus. The bypass may be triggered upon certain conditions related to the rotation speeds of the drill string or other conditions such as the pressure of the drilling fluids. For example, the drill string may be rotated in some protocol of operation (e.g., stop at certain rpm, and/or stop at certain other rpm) to describe a recognizable series of signals to an accelerometer and/or microprocessor that will communicate to pumps or valves to operate or pause/stop operations.

A drilling system having retractable wings and method of using same. The system includes at least one wing, which can extend from the system once it engages in a casing and abuts against an abutment ring at the bottom end of the casing. When the system starts drilling a hole into the ground, the casing is installed down the hole. In one configuration, the at least one wing is at least partially retracted into the drilling system and locked in this position. In another configuration, the at least one wing extends from the drilling system and locks into an extended position. The system can be connected to a down-the-hole hammer, a top-hammer drilling rod, or any other suitable rock drilling tool/apparatus, and can be used with a single and a dual rotary drilling tool/apparatus.

A drilling system having retractable wings and method of using same. The system includes at least one wing, which can extend from the system once it engages in a casing and abuts against an abutment ring at the bottom end of the casing. When the system starts drilling a hole into the ground, the casing is installed down the hole. In one configuration, the at least one wing is at least partially retracted into the drilling system and locked in this position. In another configuration, the at least one wing extends from the drilling system and locks into an extended position. The system can be connected to a down-the-hole hammer, a top-hammer drilling rod, or any other suitable rock drilling tool/apparatus, and can be used with a single and a dual rotary drilling tool/apparatus.

A drilling system having retractable wings and method of using same. The system includes at least one wing, which can extend from the system once it engages in a casing and abuts against an abutment ring at the bottom end of the casing. When the system starts drilling a hole into the ground, the casing is installed down the hole. In one configuration, the at least one wing is at least partially retracted into the drilling system and locked in this position. In another configuration, the at least one wing extends from the drilling system and locks into an extended position. The system can be connected to a down-the-hole hammer, a top-hammer drilling rod, or any other suitable rock drilling tool/apparatus, and can be used with a single and a dual rotary drilling tool/apparatus.

A drilling system having retractable wings and method of using same. The system includes at least one wing, which can extend from the system once it engages in a casing and abuts against an abutment ring at the bottom end of the casing. When the system starts drilling a hole into the ground, the casing is installed down the hole. In one configuration, the at least one wing is at least partially retracted into the drilling system and locked in this position. In another configuration, the at least one wing extends from the drilling system and locks into an extended position. The system can be connected to a down-the-hole hammer, a top-hammer drilling rod, or any other suitable rock drilling tool/apparatus, and can be used with a single and a dual rotary drilling tool/apparatus.

A system and method for stall recovery of mud motors may be implemented in a steering control system. The stall recovery system and method may involve automatic detection of a stall of a mud motor during drilling controlled by the steering control system, and may respond to the stall in a rapid and controlled manner to avoid or minimize damage to the mud motor, such as by immediately reducing mud pressure and stopping rotary drilling, if used, faster than a typical human operator could perform. The stall recovery system and method may farther take actions to automatically restart drilling.

A system and method for stall recovery of mud motors may be implemented in a steering control system. The stall recovery system and method may involve automatic detection of a stall of a mud motor during drilling controlled by the steering control system, and may respond to the stall in a rapid and controlled manner to avoid or minimize damage to the mud motor, such as by immediately reducing mud pressure and stopping rotary drilling, if used, faster than a typical human operator could perform. The stall recovery system and method may farther take actions to automatically restart drilling.

An arrangement for generating a resistivity image having a drill bit with cutters configured to be placed within a wellbore, the cutters configured to create further sections of the wellbore upon rotation, the drill bit having an end with threads for engagement, at least one section of drill string connected to the drill bit through a matching set of threads for engagement, a receiver toroid connected to the at least one section of drill string along at least a portion of the drill string, a transmitter toroid connected to the at least one section of drill string and located at least a portion of the drill string away from the receiver toroid, at least one stabilizer connected to the at least one section of drill string, a power source connected to the transmitter toroid and the receiver toroid, an electrode arrangement placed at the drill bit, wherein the electrode arrangement is electrically connected to the drill bit through a non-linear circuit element and a computer arrangement connected to the receiver toroid.