A control unit can comprise a housing and circuitry disposed within the housing. The circuitry can comprise a communications module, a memory, and a processor in communication with the memory and the communications module. A power source can be disposed within the housing. An input port that is configured to mate with a complementary output of a sensor unit that is external to the housing. The input port can be in communication with the circuitry. The input port can be configured to interface with the sensor unit.

A control unit can comprise a housing and circuitry disposed within the housing. The circuitry can comprise a communications module, a memory, and a processor in communication with the memory and the communications module. A power source can be disposed within the housing. An input port that is configured to mate with a complementary output of a sensor unit that is external to the housing. The input port can be in communication with the circuitry. The input port can be configured to interface with the sensor unit.

Raw signal measurements can be received by sensors in a wellbore. Borehole effects can affect the raw signal measurements. The raw signal measurements can be converted into ratio signals having attenuation and phase shift. An apparent resistivity can be determined from the ratio signals. Mud resistivity can be determined based on apparent resistivity, at least part of the raw signal measurements, and the borehole size. A true resistivity can be determined based on the mud resistivity and at least part of the ratio signals. The raw signal measurements and the ratio signals can be updated based on the true resistivity. Steps can be repeated to determine a corrected true resistivity. Based on the true resistivity value and updated raw signal measurements and ratio signals, an operating characteristic of a well tool can be caused to be adjusted.

Raw signal measurements can be received by sensors in a wellbore. Borehole effects can affect the raw signal measurements. The raw signal measurements can be converted into ratio signals having attenuation and phase shift. An apparent resistivity can be determined from the ratio signals. Mud resistivity can be determined based on apparent resistivity, at least part of the raw signal measurements, and the borehole size. A true resistivity can be determined based on the mud resistivity and at least part of the ratio signals. The raw signal measurements and the ratio signals can be updated based on the true resistivity. Steps can be repeated to determine a corrected true resistivity. Based on the true resistivity value and updated raw signal measurements and ratio signals, an operating characteristic of a well tool can be caused to be adjusted.

A method and system for a rotary steerable system (RSS). The method may comprise disposing the RSS into a borehole, identifying a failure from the one or more tracking measurements, the mechanical operation of the RSS, or the one or more sensors from a diagnostic review. Additionally, the method may further comprise flagging the failure with a failure code and reporting the failure and its mitigation actions to personnel in real time. The system may comprise one or more sensors configured to measure a location the RSS in a formation from one or more tracking measurements and monitor a mechanical operation of the RSS. The system may further comprise an information handling system.

A method for determining tortuosity, e.g., in an oilfield well includes obtaining a planned trajectory for a hole, and obtaining a first survey of the hole using a sensor deployed into the hole. The first survey includes a first surveyed position at a first depth of the hole and a second surveyed position at a second depth of the hole, and no surveyed positions between the first and second depths. The method further includes simulating a second survey of the hole between the first and second depths using a model. The second survey includes a plurality of simulated positions of the hole between the first and second depths. The method includes determining that the simulated position at the second depth is proximal to the second surveyed position, and visualizing a trajectory of the hole based on the first and second surveys.

A ranging signal and a reference signal are generated. The reference signal has a lower frequency than the ranging signal. The reference signal is transmitted through a geological formation to be received by a ranging tool in a ranging well while the ranging signal is launched down a target well. The reference signal is reconstructed in the ranging well and a signal that is a combination of the ranging signal launched from the target well and noise are received in the ranging well. The received signal may be in the form of magnetic or electric field values or changes in these fields. The reconstructed reference signal, in combination with the received signal, is used to produce a filtered ranging signal. A relative location of the target well can then be determined in relation to the ranging well based on the filtered ranging signal. The location information can be used to direct drilling operations.

A ranging signal and a reference signal are generated. The reference signal has a lower frequency than the ranging signal. The reference signal is transmitted through a geological formation to be received by a ranging tool in a ranging well while the ranging signal is launched down a target well. The reference signal is reconstructed in the ranging well and a signal that is a combination of the ranging signal launched from the target well and noise are received in the ranging well. The received signal may be in the form of magnetic or electric field values or changes in these fields. The reconstructed reference signal, in combination with the received signal, is used to produce a filtered ranging signal. A relative location of the target well can then be determined in relation to the ranging well based on the filtered ranging signal. The location information can be used to direct drilling operations.

Methods for sensing formation properties while drilling a well are described. An antenna system and transceiver electronics system are disposed on a drill collar segment. The antenna system includes at least one transmitter antenna for creating an electromagnetic field and at least one receiver antenna for detecting the electromagnetic field. At least one antenna in the antenna system is a magnetic dipole based antenna having at least two slot based magnetic dipoles. The slot based magnetic dipoles include slots in an outer surface of the drill collar segment, wire holes beneath the outer surface connecting the slots with each other and with the transceiver electronics system, a ferrite rod placed in each slot, and, at least one continuous antenna wire passing through the slots and the wire holes.

A method of predicting three-dimensional fracture geometry in a subterranean region of interest is disclosed. The method includes obtaining a strain tensor for the subterranean region of interest, calculating a set of principal strain components from the strain tensor, and determining a strain cyclide from the set of principal strain components. The method further includes calculating a set of quadrimodal fault normal vectors from the strain cyclide and determining an in-plane shear strain magnitude and a shear strain orientation from the set of quadrimodal fault normal vectors.