Abstract: The operational position of a sliding sleeve is detected using an electrode-type logging tool. The logging tool generates a baseline log of the sliding sleeve in a non-actuated position, and a response log of the sliding sleeve in an actuated position. The baseline and response logs are then compared in order to determine the operational position of the sliding sleeve.

Abstract: A system and method according to which a downhole component positioned behind a casing is powered, the casing extending within an oil and gas wellbore that traverses a subterranean formation. Powering the downhole component may include inducing an electrical current to flow in the casing; permitting the electrical current to flow out of the casing to create a first potential difference between a first point and a second point spaced therefrom, the first and second points being located behind the casing; utilizing the first potential difference to store electrical power; and supplying the stored electrical power to the downhole component positioned behind the casing to thereby power the downhole component. The system may include a power source in electrical communication with the casing; a power harvester positioned behind the casing and in electrical communication with the downhole component; and a current return unit in electrical communication with the power source.

Abstract: An example method may include computing a database for an ideal representation of a galvanic tool, and determining internal coupling impedance between at least one monitor electrode of the galvanic tool and a reference. Voltage and current measurements from the galvanic tool positioned within a formation may be received. A formation resistivity from the voltage and current measurements may be calculated based, at least in part, on the database and the determined internal coupling impedances.

Abstract: Hybrid inversion processing techniques are implemented that result in improved speed and accuracy of determining formation properties using log data, for example, from an multi-component induction logging tool. Logging data relating to the formation of interest is obtained and used as an input. High frequency noise is then removed from the logging data and bed-boundary determination is performed using the logging data. An adaptive low pass filter is applied to the logging data and the logging data is inverted. The inverted logging data is correct and enhanced by determining one or more weights based on one or more quality indicators. The inverted logging data may then be visually interpreted and used to adjust one or more drilling parameters.

Abstract: Fiber optic sensors are described for detecting the operational position of a downhole moveable device. In one example, an electric or magnetic field is emitted into the wellbore and interacts with the moveable assembly, thereby producing a secondary electric or magnetic field. The secondary field is detected by a fiber optic sensor which produces a corresponding response signal. The response signal is then processed in a variety of ways to determine the operational position of the moveable device. In another example, the operational position is determined using fiber optic temperature or acoustic sensors. A temperature or acoustic vibration reading is acquired before and after actuation of the moveable device. The two readings are then compared to determine the operation position of the moveable device.

Abstract: A corrosion detection system for a pipe may include a corrosion detection tool. The corrosion detection tool may include a transmitter and a receiver. The transmitter and receiver have measurements associated with each and these measurements may be used to determine an impedance. Derived constants match a numerical model that is based on the measurements associated with the transmitter and the nominal thickness of the pipe. The information related to the thickness of a pipe surrounding the corrosion detection is based on the derived constants and the impedance. This thickness of the pipe may be used to determine if a section of a pipe has a defect, such as, corrosion.

Abstract: Hybrid inversion processing techniques are implemented that result in improved speed and accuracy of determining formation properties using log data, for example, from an multi-component induction logging tool. Logging data relating to the formation of interest is obtained and used as an input. High frequency noise is then removed from the logging data and bed-boundary determination is performed using the logging data. An adaptive low pass filter is applied to the logging data and the logging data is inverted. The inverted logging data is correct and enhanced by determining one or more weights based on one or more quality indicators. The inverted logging data may then be visually interpreted and used to adjust one or more drilling parameters.

Abstract: A substance saturation sensing method includes making a resistivity measurement of a formation proximate to a well with a logging tool prior to installation of a casing string in the well. After the casing string is installed in the well, a first set of measurements of the formation is made with a monitoring system to generate a measured response. A set of calibration values is calculated based on the first set of measurements to produce a resistivity that matches the resistivity measurement. A second set of measurements of the formation is made with the monitoring system during or after saturating of a substance occurs in the formation. At least one parameter indicative of the saturating of the substance in the formation is determined based on the second set of the measurements and the set of calibration values.

Abstract: The disclosure concerns a device for obtaining electromagnetic measurements in a wellbore. In one implementation, the device includes an electromagnetic source carried by the device and a metamaterial arranged to cover a portion of the device in order to divert electromagnetic waves from the source around the covered portion of the device. In one version, the electromagnetic radiation from the source impinging on the portion of the device covered by the metamaterial, and on the electronics carried by the devices that are covered by the metamaterial is reduced. Depending on the implementation, the electromagnetic source may be an antenna, such as a coil antenna. Also, the antenna coil may be wrapped circumferentially around the tool.

Abstract: The disclosure concerns an electromagnetic logging tool for recording the electromagnetic properties of a subterranean rock formation. One version of the disclosure includes an electromagnetic transmitter that transmits an electromagnetic signal into a downhole formation, an electromagnetic receiver that receives the electromagnetic signal formation; and a cavity antenna in which the interior of the cavity contains a metamaterial made up of a plurality of unit cells that include split ring resonators or other devices such as electric-LC resonators.

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. Each communication assembly is configured to cause electrodes of a fluid sensing assembly to inject currents into fluids in one or more regions of the annulus surrounding the casing, and to obtain excitation responses from electrodes of the fluid sensing assembly, where the excitation responses vary based on electrical properties of fluids in one or more regions of the annulus surrounding the casing. Control is provided to control which electrodes of the fluid sensing assembly will inject currents and generate excitation responses and to control which electrodes of the fluid sensing assembly will sense the currents. Additional apparatus, systems, and methods are disclosed.

Abstract: A well monitoring system includes a plurality of transmitter coils coupled to an exterior of a casing positioned within a wellbore, wherein one or more first transmitter coils are positioned at a first location and one or more second transmitter coils are positioned at a second location axially offset from the first location. At least one receiver coil is coupled to the exterior of the casing and positioned at the second location. A power source is communicably coupled to the one or more first and second transmitter coils. The one or more first transmitter coils generates a magnetic field detectable by the at least one receiver coil, and the one or more second transmitter coils generates a bucking signal that minimizes a direct coupling between the one or more first transmitter coils and the at least one receiver coil.

Abstract: The operational position of a moveable device is detected using an electromagnetic induction logging tool. The logging tool generates a baseline log of the moveable device in a non-actuated position, and a response log of the moveable device in an actuated position. The baseline and response logs are then compared in order to determine the operational position of the moveable device.

Abstract: An example system includes an electrode-based tool for deployment in a downhole environment. The electrode-based tool has a plurality of current electrodes, at least one voltage monitoring electrode, at least one return electrode, and electronics to collect one or more voltage measurements from the at least one voltage monitoring electrode as current from at least one of the plurality of current electrodes is injected into the downhole environment and flows to the at least one return electrode. The system also includes at least one processor to estimate leakage current between at least one of the plurality of current electrodes and the at least one return electrode based on the collected one or more voltage measurements and a predetermined internal impedance model or table. The at least one processor is configured to derive a corrected downhole environment parameter based at least in part on the estimated leakage current.

Abstract: The operational position of a sliding sleeve is detected using an electrode-type logging tool. The logging tool generates a baseline log of the sliding sleeve in a non-actuated position, and a response log of the sliding sleeve in an actuated position. The baseline and response logs are then compared in order to determine the operational position of the sliding sleeve.

Abstract: A method includes deploying an electromagnetic (EM) defect detection tool in a borehole having one or more tubular strings. The method also includes collecting measurements by the EM defect detection tool as a function of measured depth or position. The method also includes using the measurements and a first inversion process to determine a defect in the one or more tubular strings. The first inversion process involves a cost function having a misfit term and having a stabilizing term with nominal model parameters. The method also includes performing an operation in response to the determined defect.

Abstract: A system can include a current source electrically connected to casing in a wellbore, and a sensor including a monitoring electrode, a potential difference between the casing and the electrode resulting from current applied by the current source, and the potential difference indicating an impedance of a substance in an annulus external to the casing. A method can include positioning sensors spaced apart along a casing in a wellbore, each of the sensors including an electrode in electrical contact with a substance in an annulus, inducing current in the casing, and measuring a potential difference between the casing and the electrode at each sensor. Another system can include a current source, the current source being electrically connected to casing in a wellbore, and a sensor including a monitoring electrode and an electro-optical transducer that converts a potential difference between the casing and the electrode into strain in an optical waveguide.

Abstract: Apparatus, systems, and methods may operate to detect rugosity in a borehole. Additional activity may include generating a rugosity correction, responsive to detecting rugosity in the borehole, by finding an effective borehole diameter, consistent with the presence of rugosity, for which a simulation of a model of the borehole using the effective borehole diameter generates simulation resistivity measurements that match, within a tolerance, resistivity measurements before execution of a borehole correction algorithm. Additional activity may include applying rugosity correction by generating resistivity logs, using the effective borehole diameter, that are corrected for rugosity and borehole effect. Additional apparatus, systems, and methods are disclosed.

Abstract: Metamaterials are used in well logging measurement tools to provide high directionality galvanic and induction tools having metamaterial focusing. Using metamaterial lenses, currents injected by galvanic tools can be focused in both axial and azimuthal directions. In addition, the focus plane can be shifted away from the tool body into a borehole formation, making measurements more sensitive to zones of interest and less sensitive to boreholes and invaded zones. Another metamaterial lens can bend injected currents toward the head of the tool, adding a look-ahead functionality.

Abstract: A calibration system for an electromagnetic (EM) tool includes a processor. The processor employs the EM tool to measure responses at each of a plurality of channels. The processor records the measured responses at each of the channels in an EM data log for the channel. The processor determines a nominal value of each of the channels, as being equal to a histogram peak of the EM data log. The processor selects one or more calibration points from the EM data log for a particular channel, based on a difference between the nominal value of the particular channel and the measured response at the calibration point being greater than a particular threshold. The processor determines a plurality of parameters by reducing a misfit between synthetic data and both the nominal values of the channels and the measured responses of the channels at the selected one or more calibration points.