Abstract: The present disclosure relates to a composite 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: Systems and methods for active ranging-while-drilling (ARWD) for collision avoidance and/or well interception. A method for ranging while drilling may comprise employing a rotating magnet assembly to induce a changing magnetization and/or electric current in a conductive member disposed in a target wellbore, wherein the rotating magnet assembly may be employed in a second wellbore; measuring at least one component of a magnetic gradient tensor using receivers; and calculating a relative location of the conductive member based at least in part on the measurements of the at least one component of the magnetic gradient tensor.

Abstract: A communication system that is positionable in a wellbore can include a first transceiver for coupling externally to a casing string. The first transceiver can be for wirelessly transmitting data by generating and modulating a surface wave that propagates along an interface surface. The surface wave can include an electromagnetic wave that has a magnetic field or an electric field that is at an acute angle to a direction of propagation of the surface wave. The communication system can also include a second transceiver for coupling to the casing string and for wirelessly receiving the surface wave and detecting the data.

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: 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: In some example embodiments, a system includes a drill string having a drill bit. The drill string extends through at least part of a well bore. The system also includes a first vibrational sensor, positioned on the drill bit to measure, at a first location on the drill string, an amplitude of one or more of an axial vibration and a lateral vibration. The system also includes a second vibrational sensor, positioned above the drill bit and on the drill string. The second vibration sensor is to measure, at a second location on the drill string, one or more of an axial vibration and a lateral vibration. The system includes a processor unit to determine a type of vibration based on a comparison of the amplitude at the first location to the amplitude at the second location, wherein the type of vibration is at least one of bit whirl of the drill bit and a while of a bottom hole assembly that is part of the drill string.

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: In some example embodiments, a system includes a drill string having a drill bit. The drill string extends through at least part of a well bore. The system also includes a first vibrational sensor, positioned on the drill bit to measure, at a first location on the drill string, an amplitude of one or more of an axial vibration and a lateral vibration. The system also includes a second vibrational sensor, positioned above the drill bit and on the drill string. The second vibration sensor is to measure, at a second location on the drill string, one or more of an axial vibration and a lateral vibration. The system includes a processor unit to determine a type of vibration based on a comparison of the amplitude at the first location to the amplitude at the second location, wherein the type of vibration is at least one of bit whirl of the drill bit and a while of a bottom hole assembly that is part of the drill string.

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.

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: Various embodiments include apparatus and methods to estimate properties of rock, drill bit, or a combination thereof associated with a drilling operation. The properties can include, but are not limited to, rock chip size, drill bit dullness, drilling efficiency, or a combination selected from rock chip size, drill bit dullness, and drilling efficiency. The estimate may be accomplished from correlating detected acoustic emission with detected electromagnetic emissions. In various embodiments, formation brittleness may be determined. The various estimates may be used to direct a drilling operation. Additional apparatus, systems, and methods are disclosed.

Abstract: A well casing detection system includes a well casing and a ranging tool. The well casing includes a beacon with a resonant structure and a power supply. The ranging tool includes a magnetic field inducer, a magnetic field detector, and a power supply. This detection system is used to remotely detect well casing while it is deployed in a well, and may be used in conjunction with measurement while drilling (MWD) methods, logging while drilling (LWD) methods, coiled tubing drilling methods, steam assisted gravity drainage (SAGD), and wireline drilling methods, such that an operator may simultaneously direct the operation of a drill while operating the detection system.

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: 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: An apparatus and method may operate to mount one or more communication assemblies relative to the exterior of a casing being placed in a borehole. Two communication assemblies can be placed in longitudinally spaced relation to one another along the casing, wherein each communication assembly is configured to obtain excitation responses from electrodes of a fluid sensing component, where the excitation responses vary based on properties of fluids in one or more regions of the annulus surrounding the casing. Additional apparatus, systems, and methods are disclosed.

Abstract: A communication system that is positionable in a wellbore can include a first transceiver positioned externally to a casing string. The first transceiver can be operable to detect a presence or an absence of a surface wave; determine a location of a fluid in the wellbore based on the presence or the absence of the surface wave; and transmit data indicative of the location to a second transceiver. The surface wave can include an electromagnetic wave that has a magnetic field or an electric field that is non-transverse to a direction of propagation of the surface wave. The communication system can also include the second transceiver, which can be positioned externally the casing string and operable to receive the data.

Abstract: A communication system that is positionable in a wellbore can include a first transceiver for coupling externally to a casing string. The first transceiver can be for wirelessly transmitting data by generating and modulating a surface wave that propagates along an interface surface. The surface wave can include an electromagnetic wave that has a magnetic field or an electric field that is at an acute angle to a direction of propagation of the surface wave. The communication system can also include a second transceiver for coupling to the casing string and for wirelessly receiving the surface wave and detecting the data.

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: 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: 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.