One exemplary embodiment provides a dual-speed dual-core enhanced drilling equipment which comprises an outer cylinder, a downhole power device, a large cutting head and a small cutting head, wherein the large cutting head is provided with a first centerline, a through hole arranged along the first centerline and a first diameter; the outer cylinder is sleeved outside the downhole power device and forms an annular space, and the outer cylinder directly or indirectly connects the upper drill string with the large cutting head so that the large cutting head and the downhole power device can rotate together with the upper drill string; the downhole power device is provided with a power generation section capable of generating power and a rotation output section which penetrates through the through hole to be connected with the small cutting head and provides independent power for the small cutting head, so that the small cutting head revolves around the first centerline under the driving of the upper drill string while rotating under the driving of the downhole power device. The exemplary embodiment can avoid the problem that the linear velocity of the central point of the large cutting head is zero, and is beneficial to improving the drilling speed.

A drilling tool includes a pilot bit coupled to an eccentric reamer that has a reaming side and a stabilizing side. A fluid passageway extends between the reamer and the pilot bit, and the tool includes at least one upwardly-directed nozzle in fluid communication with the fluid passageway and positioned on the stabilizing side of the reamer. The reamer may include a plurality of angularly spaced blades on the reaming side that radially extend a first distance, the reamer blades being disposed within a first arcuate segment defined by the two most distant reamer blades. One or more stabilizing blades extend a second distance that is less than the first distance, the stabilization blades being disposed within a second arcuate segment defined by the two most distant reamer blades and that has the angular measure equal to 360 degrees minus the first arcuate segment.

Systems and methods for adjusting a drilling operation, the methods and systems include obtaining, at a control system, a first drilling characteristic associated with a first drilling operation device that is part of a drilling system on a drill string; obtaining, at the control system, a second drilling characteristic associated with a second drilling operation device located apart from the first drilling operation device along the drill string; and controlling, with the control system, at least one adjustable element of the first drilling operation device in response to at least one of the obtained first drilling characteristic and the second drilling characteristic, wherein adjustment of the at least one adjustable element causes a change in at least one of the first drilling characteristic and the second drilling characteristic.

In one embodiment, a radio-frequency identification device for use in a wellbore includes a housing made of a polymer; and an antenna disposed in the housing. The polymer may be selected from the group consisting of an elastomer, a plastic, a rubber, a thermoplastic elastomer, and combinations thereof. The RFID device may also include a fill material disposed in the housing.

In some aspects, the present disclosure includes systems and methods for rotatably coupling a bottom-hole assembly to a drilling shaft for use in subterranean drilling operations. In one embodiment, the methods of the present disclosure are suitable for underreaming a portion of a wellbore. The methods may comprise rotating a drilling shaft coupled to a drill bit about its axis to form a wellbore; engaging a first locking mechanism rotatably coupled to the drilling shaft with a second locking mechanism coupled to a housing to rotatably couple the drilling shaft and the housing; expanding an expandable reamer attached to the housing; and rotating the housing to widen at least a portion of the wellbore uphole from the drill bit. The bottom-hole may comprise one or more actuators that are selectively operable to engage the first and second locking mechanisms and expand the expandable reamer.

A downhole cutting apparatus includes a cutter block. The cutter block includes a formation facing surface with cutting elements coupled thereto. The cutting elements are arranged in rows that may extend at an angle across a width of the formation facing surface. Mud flutes may optionally be located between rows of cutting elements. A gauge portion of the formation facing surface may be adjacent a leading edge having reinforcement members coupled thereto.

A reamer for increasing the diameter of a wellbore includes an eccentric reamer lobe having at least one cutting blade and a roller, wherein the roller encompasses the circumference of the reamer.

A downhole cutting tool which may be a reamer or a mill has a rotary tool body with at least one block which carries hard-faced cutters and projects or is extensible from the tool body. A radially outward facing part of the cutter block defines a channel for fluid flow which extends generally axially along the cutter block. The channel is configured such that at least the rotationally trailing edge of the channel extends along the block in one or more directions which are inclined relative to the tool axis. This reduces or avoids the amount of channel edge parallel to the tool axis and thereby mitigates whirling and/or or vibration.

A downhole-milling-tool method for milling through hard substances, such as barite, found in underground wells, providing a stepped increase of diameters and positioning of carbide cutters and appropriate positioning of fluid ports and channels, to provide removal of cuttings and cooling and lubricating of the cutting head, in turn providing more efficiency and a better rate of penetration (ROP).

Disclosed is a hammer reamer comprising cutting wheels, a product-pulling feature, and a hammer component operable to deliver a percussive cycle of an internal piston component. Notably, an internal impact surface within the head of the hammer reamer is positioned relative to the piston component in the hammer consistent with a sweet spot position of a drill bit used in a pilot boring configuration. Unlike a slidably engaged drill bit, however, the internal impact surface in the hammer reamer is fixed in place so that the impact surface remains in the sweet spot of the piston stroke range. In this way, even though the hammer reamer is being pulled back through a bore while the drill string is being retracted, the hammer component may continue to deliver percussive blows to the hammer reamer head to introduce a vibratory force that contributes to the efficiency of the reaming process.