Abstract: An electromagnetic (EM) telemetry system includes an EM transmitter configured to transmit EM signals downhole and multiple sensors each configured to communicate with the EM transmitter and with another of the multiple sensors. Each sensor is placed a distance from another sensor along a length of a wellbore in the EM telemetry system. The EM telemetry system also includes a processor configured to select two or more sensors of the multiple sensors based on a signal to noise ratio (SNR) of an EM signal received from the two or more selected sensors, a depth of the EM transmitter, or both.

Abstract: An electromagnetic (EM) telemetry system includes an EM transmitter configured to transmit EM signals downhole and multiple sensors each configured to communicate with the EM transmitter and with another of the multiple sensors. Each sensor is placed a distance from another sensor along a length of a wellbore in the EM telemetry system. The EM telemetry system also includes a processor configured to select two or more sensors of the multiple sensors based on a signal to noise ratio (SNR) of an EM signal received from the two or more selected sensors, a depth of the EM transmitter, or both.

Abstract: An electromagnetic (EM) telemetry system includes an EM transmitter configured to transmit EM signals downhole and multiple sensors each configured to communicate with the EM transmitter and with another of the multiple sensors. Each sensor is placed a distance from another sensor along a length of a wellbore in the EM telemetry system. The EM telemetry system also includes a processor configured to select two or more sensors of the multiple sensors based on a signal to noise ratio (SNR) of an EM signal received from the two or more selected sensors, a depth of the EM transmitter, or both.

Abstract: A method for conducting survey measurements in a ranging operation between a first well and a second well include generating an electromagnetic field in a downhole location in the first well and scanning for the electromagnetic field in a downhole location in the second well. When at least one characteristic of the electromagnetic field is detected, the method includes automatically initiating survey measurements for a ranging operation without receiving a downlink command from surface.

Abstract: An electromagnetic (EM) telemetry system includes an EM transmitter configured to transmit EM signals downhole and multiple sensors each configured to communicate with the EM transmitter and with another of the multiple sensors. Each sensor is placed a distance from another sensor along a length of a wellbore in the EM telemetry system. The EM telemetry system also includes a processor configured to select two or more sensors of the multiple sensors based on a signal to noise ratio (SNR) of an EM signal received from the two or more selected sensors, a depth of the EM transmitter, or both.

Abstract: A method for conducting survey measurements in a ranging operation between a first well and a second well include generating an electromagnetic field in a downhole location in the first well and scanning for the electromagnetic field in a downhole location in the second well. When at least one characteristic of the electromagnetic field is detected, the method includes automatically initiating survey measurements for a ranging operation without receiving a downlink command from surface.

Abstract: The expandable tools disclosed herein may be used as an underreamer to enlarge a borehole, or may be used to stabilize a drilling system in a previously underreamed borehole or in a borehole that is being underreamed while drilling progresses. At least one moveable arm, which translates between a collapsed and expanded position in response to a differential pressure between the axial flowbore and the wellbore, includes a borehole-engaging surface with cutting elements and at least one nozzle to direct a fluid across the borehole-engaging surface. Flow directing elements on the external surface of the tool may be used to decrease the flow area in an annulus between the tool and the wellbore and directs fluid flow in the annulus toward the borehole-engaging surface.

Abstract: A cutting structure for use with a reamer in enlarging a borehole in a subterranean formation includes a plurality of cutter blocks, radially extendable from a reamer body away from a central axis of the reamer body, each of the plurality of cutter blocks comprising at least one cutter blade thereon, wherein an angular spacing about the central axis of the reamer body between the at least one cutter blade on each of the plurality of cutter blocks is unequal.

Abstract: A cutting structure for use with a reamer in enlarging a borehole in a subterranean formation includes a plurality of cutter blocks, radially extendable from a reamer body away from a central axis of the reamer body, each of the plurality of cutter blocks comprising at least one cutter blade thereon, wherein an angular spacing about the central axis of the reamer body between the at least one cutter blade on each of the plurality of cutter blocks is unequal.

Abstract: A cutting structure for use with a reamer in enlarging a borehole in a subterranean formation includes a plurality of cutter blocks, radially extendable from a reamer body away from a central axis of the reamer body, each of the plurality of cutter blocks comprising at least one cutter blade thereon, wherein an angular spacing about the central axis of the reamer body between the at least one cutter blade on each of the plurality of cutter blocks is unequal.

Abstract: A thrust bearing system for a roller cone rock bit includes at least one roller cone disposed on a leg having an air channel therethrough, the thrust bearing system including a primary thrust bearing surface on the leg configured to contact a corresponding primary bearing surface on the roller cone, wherein the primary thrust bearing surface on the leg includes at least one air circulation port in fluid communication with the air channel.

Abstract: Various embodiments of an expandable downhole tool for use in drilling of a wellbore are disclosed. The expandable tools disclosed herein may be used as an underreamer to enlarge a borehole, or may be used to stabilize a drilling system in a previously underreamed borehole or in a borehole that is being underreamed while drilling progresses. The various embodiments of the expandable tools disclosed herein have a higher hydraulic capacity than prior art underreamers. An increase in hydraulic energy delivered to the cutting structures may advantageously improve the rate of removal of cuttings from the cutting structures (improved cuttings evacuation), may decrease cutter element wear, and may prevent damage or premature failure. Improved cuttings evacuation may also provide for improved cutting action and increased penetration rates.

Abstract: A cutting structure for use with a reamer in enlarging a borehole in a subterranean formation includes a plurality of cutter blocks, radially extendable from a reamer body away from a central axis of the reamer body, each of the plurality of cutter blocks comprising at least one cutter blade thereon, wherein an angular spacing about the central axis of the reamer body between the at least one cutter blade on each of the plurality of cutter blocks is unequal.

Abstract: A thrust bearing system for a roller cone rock bit includes at least one roller cone disposed on a leg having an air channel therethrough, the thrust bearing system including a primary thrust bearing surface on the leg configured to contact a corresponding primary bearing surface on the roller cone, wherein the primary thrust bearing surface on the leg includes at least one air circulation port in fluid communication with the air channel.