A drill collar having at least one pocket for receiving at least one component. The at least one pocket includes a rectangular portion that extends from a first end to a second end. The rectangular portion also includes a base surface. Each of the first and the second ends includes a transition surface extending from the base surface to a pair of shoulder surfaces and a channel. The pair of shoulder surfaces and a surface of the channel are parallel to the base surface. The channel extends to an end pocket that can be in communication with an aperture.

Aspects of the subject technology relate to a sensor for a downhole tool. The downhole tool can include a collar and a sensor. The sensor can be secured to the collar for measuring one or more operational characteristics of the downhole tool during operation of the downhole tool including the performance characteristics of a drill motor. The sensor can include a substrate. The sensor can also include a plurality of strain gauges disposed on the substrate. The plurality of strain gauges can be configured to measure axial strains and torsional strains on the collar for measuring the one or more operational characteristics of the downhole tool.

An apparatus for determining a location of an inner string in an outer string includes an axis parallel to a longitudinal axis of the inner string, and a tagging assembly disposed at a tagging location in the outer string, the outer string configured to be deployed into a borehole in a subterranean region, the inner string configured to be advanced through the outer string. The tagging assembly includes a stop component configured to obstruct axial movement of the inner string through the outer string at the tagging location, the stop component configured to be displaced in response to an axial force applied to the stop component by the inner string, to permit the inner string to advance axially beyond the tagging assembly.

An apparatus for determining a location of an inner string in an outer string includes an axis parallel to a longitudinal axis of the inner string, and a tagging assembly disposed at a tagging location in the outer string, the outer string configured to be deployed into a borehole in a subterranean region, the inner string configured to be advanced through the outer string. The tagging assembly includes a stop component configured to obstruct axial movement of the inner string through the outer string at the tagging location, the stop component configured to be displaced in response to an axial force applied to the stop component by the inner string, to permit the inner string to advance axially beyond the tagging assembly.

A crash avoidance system or crowding avoidance sub (CAS) may be a dedicated or adapted subassembly (sub) in a bottom hole assembly (BHA), such as somewhere above the motor and bit, or between a drill string and BHA. With data lines in a modified housing and flex lines for relative, linear, axial motion between movable parts of a single sub, sensors are contemplated to put a CAS ahead of a cushion, jar, or shock sub, even a motor. However, sensors are best connected to an Intellisys™ data connection system providing a data stream to a computer on the surface. Certain preprocessing may be done down hole, but need not be. Control of the drive system of the hook feed rate is directly controlled in real time by a data station receiving, and operating based on, certain information received from the down hole sensors of the CAS.

A crash avoidance system or crowding avoidance sub (CAS) may be a dedicated or adapted subassembly (sub) in a bottom hole assembly (BHA), such as somewhere above the motor and bit, or between a drill string and BHA. With data lines in a modified housing and flex lines for relative, linear, axial motion between movable parts of a single sub, sensors are contemplated to put a CAS ahead of a cushion, jar, or shock sub, even a motor. However, sensors are best connected to an Intellisys™ data connection system providing a data stream to a computer on the surface. Certain preprocessing may be done down hole, but need not be. Control of the drive system of the hook feed rate is directly controlled in real time by a data station receiving, and operating based on, certain information received from the down hole sensors of the CAS.

A vibrational disfunction machine learning model trainer trains a vibrational disfunction classifier to identify one or more types of vibrational disfunction, or normal drilling, based on measurements of at least one of displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration acquired for the drill bit. The vibrational disfunction machine learning model trainer trains the algorithm based on data sets corresponding to characteristic behavior for one or more types of vibrational disfunction and normal drilling. The vibrational disfunction classifier operates in real time, and can operate at the drill bit and communicate vibrational disfunction identification in real time, allowing mitigation of vibrational disfunction through adjustment of drilling parameters.

A vibrational disfunction machine learning model trainer trains a vibrational disfunction classifier to identify one or more types of vibrational disfunction, or normal drilling, based on measurements of at least one of displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration acquired for the drill bit. The vibrational disfunction machine learning model trainer trains the algorithm based on data sets corresponding to characteristic behavior for one or more types of vibrational disfunction and normal drilling. The vibrational disfunction classifier operates in real time, and can operate at the drill bit and communicate vibrational disfunction identification in real time, allowing mitigation of vibrational disfunction through adjustment of drilling parameters.

A rotary cutting tool for use in a wellbore has an instrumented cutter fitted into a cavity in the tool body. The instrumented cutter body has an outer end portion exposed at the open end of a cavity and is connected to the tool body through at least one connecting section having a smaller cross-section and greater compliance than the outer end portion. The outer end portion and the connecting section are slightly movable within the cavity but the cavity surrounds at least part of the outer end portion sufficiently closely to limit transverse movement to elastic strain of the compliant connecting portion. One or more sensors, which may be strain gauges, are used to measure force on the outer end portion in a plurality of directions transverse to the cavity and causing elastic strain of the at least one connecting section.

A rotary cutting tool for use in a wellbore has an instrumented cutter fitted into a cavity in the tool body. The instrumented cutter body has an outer end portion exposed at the open end of a cavity and is connected to the tool body through at least one connecting section having a smaller cross-section and greater compliance than the outer end portion. The outer end portion and the connecting section are slightly movable within the cavity but the cavity surrounds at least part of the outer end portion sufficiently closely to limit transverse movement to elastic strain of the compliant connecting portion. One or more sensors, which may be strain gauges, are used to measure force on the outer end portion in a plurality of directions transverse to the cavity and causing elastic strain of the at least one connecting section.