The present disclosure describes measuring bending moments within a drillstring or tool string to identify deflections (or “dog-legs”) within the string. In some systems, the bending moments a plurality of strain gauges. In some such systems the strain gauges will be arranged in a selected spacing around the circumference of the tool string, in many examples, at a common plane extending generally perpendicular to the longitudinal axis of the string proximate the strain gauges. The bending moments may be further evaluated to provide a measure of wellbore tortuosity. For example, the bending moments may be utilized to define a radius of curvature associated with the determined bending moments, which may be further correlated with a directional measurement to apply a direction to the bending moment, and therefore to the tortuosity an any given location. In many examples, the above measurements and determinations will be performed in essentially real time during a drilling operation; and will in some cases be used to perform remedial measures, where dictated.

A method and system for monitoring operation of a motor may include initially determining a no load torque versus temperature characteristic of the motor over a range of operating temperatures. After a period of operation, a no load torque value and temperature of the motor may be determined. Motor temperature may be measured by a local thermistor or the like. Motor torque may be determined from measured motor current. The motor torque and temperature may then be compared to the initial torque versus temperature characteristic to determine a change in load of said motor due to break down of motor oil, worn bearings, or similar condition. In some embodiment, the method and system may be used with a downhole tool for drilling a well, such as a rotary steerable system.

An example method includes determining a frequency response of a tuned pulse to be transmitted from a transmission element. A matching frequency envelope corresponding to a frequency envelope of the frequency response may be determined. A time domain signal corresponding to the matching frequency envelope may be determined. A series of digital pulses corresponding to the time domain signal may be determined. An analog output at a switching amplifier corresponding to the series of digital pulses may be generated. A transmission element may be excited with the analog output.

A downhole steering tool comprising a first member, fixedly coupled with a drill string, and a second member, proximate the first member and rotatable substantially freely with respect to the first member. A first sensor is operable to measure a difference in rotation rates of the first and second members. A second sensor is operable to measure a substantially real-time rotation rate of the second member in the wellbore. A tool controller is operable to process sensor signals from the first and second sensors to determine a rotation rate of the drill string. Surface-initiated changes in the rotation rate of the drill string are then utilized by the downhole steering tool for steering and other control.

A method for selecting drilling parameters for drilling a borehole penetrating the earth with a drill string. The method includes: measuring vibration-related amplitudes of the drill string during operation using one or more vibrations sensor to provide amplitude measurements; determining with a downhole processor one or more modal properties comprising one or more eigenfrequencies of the drill string using the amplitude measurements, the determination being made by including any excitation force in a white noise term of a model of the drillstring; and selecting drilling parameters that apply an excitation force at a frequency that avoids a selected range of frequencies that bound the one or more eigenfrequencies using the processor.

A modular mobility platform has extendable and retractable tractor treads for engaging the walls of a downhole environment. The extendable and retractable tractor treads allow the platform to successfully navigate longitudinally through the downhole environment. The platform is composed of a plurality of different modules removably interconnected together longitudinally. Each module has at least one specific function, such as sensing, navigation, mobility, control, communication, power, or a combination thereof. The platform has longitudinally-directed detectors for detecting the forward or reverse direction through which the platform is to travel. A front end of the platform having a sensor at the forward end thereof articulates to navigate the mobility platform laterally through splits in the downhole environment. A system and method use the modular mobility platform.

Apparatus, systems, and methods may operate to correct measured voltage data for selected weak differential measurements to provide corrected voltage data. Additional activity may include adjusting the corrected voltage data to remove level shifts in the measured voltage data caused by downhole tool impedance to provide adjusted voltage data, converting the adjusted voltage data into apparent resistivity data, inverting the apparent resistivity data to determine true resistivity values for a geological formation, and operating a controlled device according to the true resistivity values for the geological formation. Additional apparatus, systems, and methods are disclosed.

A transmitter is powered by a regulated battery voltage and is installable in one of a plurality of different housings, each housing is characterized by a different design and each can form part of an inground tool for performing an inground operation in which a drill string extends from a drill rig to the inground tool. An antenna driver drives an antenna based on the regulated voltage to emanate an electromagnetic signal for remote reception. A controller limits power consumption from the regulated voltage so as not to exceed a power consumption threshold, irrespective of installation of the transmitter in any one of the housings when the transmitter would otherwise exhibit a different power consumption for each housing design. A corresponding method is described. Features relating to power consumption threshold modification based on temperature as well as mechanical shock and vibration are described.

A well-logging system includes a downhole tool coupled to a cable. The downhole tool may measure physical parameters of a wellbore via a first plurality of sensors. The well-logging system may include wellbore equipment including a winch. The winch may traverse the downhole tool through the wellbore by spooling or unspooling the cable. The well-logging system may also include a second plurality of sensors that may measure operational parameters of the wellbore equipment. The well-logging system may further include an automation controller that is communicatively coupled to the first plurality of sensors and the second plurality of sensors. A set of defined operating instructions may be prepared during the assembly of the job. The automation controller may control the wellbore equipment based at least in part on feedback from the first plurality of sensors, feedback from the second plurality of sensors, and the defined operating instructions.

A method for drilling includes obtaining formation-measurement pairings, training a machine-learning model using the formation-measurement pairings, receiving measurements obtained by a tool positioned in a well formed in a formation, and generating a formation model of at least a portion of the formation using the machine-learning model and the measurements. The formation model represents one or more physical parameters of the formation, one or more structural parameters of the formation, or both.