Abstract: An assembly for use in a wellbore can include a plurality of sensors positioned external to a casing string. The plurality of sensors can be positioned for detecting an amount of a hydrocarbon that is present in a fluid in the wellbore and a pH of the fluid in the wellbore. The plurality of sensors can be positioned for wirelessly transmitting signals representing the amount of the hydrocarbon that is present in the fluid and the pH of the fluid to a receiving device.

Abstract: An illustrative electromagnetic logging while drilling system includes a drill string having a bottomhole assembly with a bit that operates to extend a borehole; and further includes a removable add-on antenna unit that cooperates with at least one other antenna unit in the drill string to provide electromagnetic signal measurements indicative of at least one formation property. Some embodiments of the add-on antenna unit encircle an existing tool or tubular, attaching to a sidewall readout port to receive power and exchange communications over the internal tool bus with at least one other antenna unit. At least one disclosed method embodiment includes: assembling the bottomhole assembly; securing at least one add-on antenna unit around a downhole tool or tubular in the bottomhole assembly; and using the at least one add-on antenna unit in combination with at least one other antenna in the bottomhole assembly to obtain electromagnetic signal measurements formation properties.

Abstract: An assembly for use in a wellbore can include a plurality of sensors positioned external to a casing string. The plurality of sensors can be positioned for detecting an amount of a hydrocarbon that is present in a fluid in the wellbore and a pH of the fluid in the wellbore. The plurality of sensors can be positioned for wirelessly transmitting signals representing the amount of the hydrocarbon that is present in the fluid and the pH of the fluid to a receiving device.

Abstract: In an embodiment a method of automatic adjustment of logging, processing, inversion, and visualization operations is disclosed. The method comprises gathering data about formation properties in a database, filtering the gathered data, generating rules based on the filtered data, and providing automatic adjustments to automatically adjust the logging, processing, inversion, and visualization operations. The gathered data includes a plurality of in-well measurement points and a plurality of wells in a given geological area. A quality factor is derived based on a difference between the automatic adjustments and parameters that an operator communicates as a best parameter. The quality factor is used to determine which of the gathered data is to be stored in the database. The rules are applied to a next iteration of data that is to be gathered. The method repeats until no further improvement is obtained.

Abstract: 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.

Abstract: A system having a downhole sensor device and a compression device to obtain a sparse representation of data in downhole telemetry applications is described. The downhole sensor device can collect sensor data while the downhole sensor device is within a borehole. The compression device is coupled to the downhole sensor device and configured to receive the sensor data. The compression device can determine a wavelet coefficient vector for at least one row of n-tuple vectors. The wavelet coefficient vector can have a sparse representation of one or more nonzero elements. The compression device can process the wavelet coefficient vector through a set of compression algorithms, and determine a minimal bit cost of the processed wavelet coefficient vector. The compression device can select a compression algorithm from the set of compression algorithms corresponding to the minimal bit cost. The compression device can generate compressed data based on the selected compression algorithm.

Abstract: A fracture sensing system and method is disclosed herein. The method may include positioning a transmitter and a receiver in a borehole and magnetizing a casing disposed within the borehole to magnetically saturate the casing. The transmitter and receiver may be located inside or outside of the casing. The method may also include inducing with the transmitter an electromagnetic field in a formation surrounding the borehole. The method may also comprise receiving the induced electromagnetic field at the receiver. The induced electromagnetic field may identify a fracture within the formation based, at least in part, on a contrast agent within the fracture.

Abstract: A system can include a cementing tool positionable within a casing string of a wellbore. A receiver that is positionable at the surface of the wellbore can receive an optical signal. A locator coupled to the cementing tool can generate an electrical signal in response to detecting a change in a surrounding magnetic field. A light source can generate an optical signal. A fiber optic cable can transmit the optical signal generated by the light source. A fiber reel can dispense the fiber optic cable from an end of the fiber optic cable.

Abstract: The present disclosure relates to a composite fluid including an electrically insulating foundation fluid having a dielectric constant and a dielectric strength, and an additive combined with the foundation fluid that results in a composite fluid having a dielectric constant and a dielectric strength greater than the dielectric constant and the dielectric strength of the foundation fluid.

Abstract: Video of an above ground effect of a subterranean event is received. The subterranean event is identified using Eulerian video magnification of the received video.

Abstract: A method includes introducing a resistivity logging tool including one or more transmitter coils and one or more receiver coils into a wellbore. First and second signals are then transmitted with a first transmitter coil at first and second frequencies, respectively, and a first receiver coil receives first and second response signals based on the first and second signals. A ratio between the first and second response signals is then calculated to obtain a ratio signal, and the ratio signal is processed in an inversion algorithm. One or more formation characteristics of the subterranean formation may then be determined based on the ratio signal as processed by the inversion algorithm.

Abstract: The present disclosure relates to a composite fluid including an electrically insulating foundation fluid having a dielectric constant and a dielectric strength, and an additive combined with the foundation fluid that results in a composite fluid having a dielectric constant and a dielectric strength greater than the dielectric constant and the dielectric strength of the foundation fluid.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate to receive a derived clock signal downhole, the derived clock signal being derived from a surface clock signal (associated with a surface clock), such that the frequency of the derived clock signal is less than the frequency of the surface clock signal. Further activity may include measuring the frequency of the derived clock signal in terms of an uncorrected downhole clock frequency (associated with a downhole clock) to provide a measured frequency equivalent, and correcting time measurements made using the downhole clock, based on the measured frequency equivalent, or based on an actual frequency of the downhole clock determined according to the measured frequency equivalent. Additional apparatus, systems, and methods are described.

Abstract: In an embodiment a method of automatic adjustment of logging, processing, inversion, and visualization operations is disclosed. The method comprises gathering data about formation properties in a database, filtering the gathered data, generating rules based on the filtered data, and providing automatic adjustments to automatically adjust the logging, processing, inversion, and visualization operations. The gathered data includes a plurality of in-well measurement points and a plurality of wells in a given geological area. A quality factor is derived based on a difference between the automatic adjustments and parameters that an operator communicates as a best parameter. The quality factor is used to determine which of the gathered data is to be stored in the database. The rules are applied to a next iteration of data that is to be gathered. The method repeats until no further improvement is obtained.

Abstract: An antenna assembly includes a bobbin that provides a cylindrical body that defines an outer radial surface, an inner radial surface, and a central axis. One or more channels are defined on the outer radial surface, and each channel provides a first sidewall, a second sidewall opposite the first sidewall, a floor, and a pocket jointly defined by the first sidewall and the floor. A coil including one or more wires is wrapped about the bobbin and received within the one or more channels.

Abstract: Video of an effect on equipment of an event is received. The event is identified using Eulerian video magnification of the received video.

Abstract: A drilling system including a drilling fluid with a particular impedance is disclosed. Specifically, the drilling system includes a drill string, a drill bit attached to the downhole end of the drill string, and a drilling fluid that circulates downhole through the drill string, the drilling fluid including a foundation fluid having an impedance at a frequency, and an additive combined with the foundation fluid that results in a composite fluid having an impedance different than the impedance of the foundation fluid at the frequency.

Abstract: A downhole telemetry well system transmits data at a high rate inside a tubular pipe by encoding signals on a Stoneley wave. Telemetry devices for the Stoneley mode are implemented in short pipe joints inserted at various intervals between the tubulars. Each telemetry device includes Stoneley transducers, which may act as a transmitter, receiver, or repeater. The Stoneley telemetry devices transmit and receive the Stoneley waves making up the carrier of the signal. The Stoneley telemetry devices may be powered by on-board batteries or via some remote power source.

Abstract: An apparatus and a system, as well as a method and an article, may include operating a positive displacement motor having a pair of output orifices including a selectably movable outer output orifice disposed proximate to a fixed inner output orifice. Operation may include rotating the outer output orifice about the longitudinal axis of the motor when drilling fluid is flowing through the pair of orifices to control fluid pressure pulse amplitude from the outer output orifice. Additional apparatus, systems, and methods are disclosed.

Abstract: A disclosed method includes measuring properties of a formation with a logging tool disposed in a borehole. The method also includes acquiring measurement data corresponding to the measured properties of the formation. The method also includes adjusting a control parameter for logging operations of the logging tool based on at least some of the measurement data and an adaptive learning engine within the logging tool.