Abstract: Evaluation of formations and fracture characterization based on multicomponent induction (MCI) log data includes automated calculation of biaxial anisotropy (BA) parameters by performing iterative inversion operations based on the MCI log data. Biaxially anisotropic effect corrected (BAC) logs are BA anisotropic effect corrected using the inverted BA parameters. The inverted BA parameters can also be used for identification and quantification of fractures in formations.

Abstract: A logging system includes an electromagnetic logging tool that collects at least one measurement of a subterranean formation at a borehole. The logging system also includes a processing system that generates a plurality of earth models of the subterranean formation based on the at least one measurement of the subterranean formation. The processing system projects at least one second earth model upon a well path of the borehole, and selects a model of the plurality of models based on a spatial correlation between at least one parameter of the selected model and a corresponding at least one parameter of the at least one second earth model.

Abstract: In some embodiments, an apparatus and a system, as well as methods, include operating to estimate a range of true resistivity in a geological formation, based on measurements made over multiple frequencies. Further activity may comprise selecting a subset of the measurements associated with at least one measurement frequency included in the multiple frequencies, based on the range of the true resistivity, to determine a value of a property of the geological formation. Additional methods, apparatus, and systems are disclosed.

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: An apparatus, method, and system are disclosed where the apparatus includes connecting toroid and band gap antennas in series as one hybrid transceiver unit. In this hybrid transceiver, a toroid antenna is disposed on a housing. A band gap antenna is also disposed on the housing. The band gap antenna includes a first pole disposed on the housing substantially adjacent to the toroid antenna and a second pole disposed on the housing and separated from the first pole by a band gap.

Abstract: A time-lapse seismic wavefield monitoring system for a formation includes at least one seismic wavefield source and at least one seismic wavefield sensor to collect seismic wavefield survey data corresponding to the formation in response to an emission from the at least one seismic wavefield source. The seismic wavefield survey data includes first seismic wavefield data collected at a first time and second seismic wavefield data collected at a second time. The time-lapse seismic wavefield monitoring system also includes a processing unit in communication with the at least one seismic wavefield sensor. The processing unit determines time-lapsed seismic wavefield data based on the first seismic wavefield data and the second seismic wavefield data, and performs an analysis of the time-lapsed seismic wavefield data to determine an attribute change in an earth model.

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: A method for use with a subterranean well can include modeling multiple fluid types in an annulus formed between casing and an earth formation penetrated by a wellbore, inverting electromagnetic data acquired by sensors in the well, and selecting at least one of the fluid types based on the inverting. A system for use with a subterranean well can include multiple sensors longitudinally spaced apart along a casing in a wellbore, each of the sensors imparting electromagnetic impulses to a fluid present in an annulus formed between the casing and the wellbore, and each of the sensors providing observed data indicative of at least one physical property associated with the fluid.

Abstract: In some embodiments, an apparatus and a system, as well as methods, may include operating a transmitting antenna and a receiving antenna as equivalent tilted dipoles, wherein the tilted dipoles provide a selection of equivalent tilt angles for at least one of the transmitting antenna or the receiving antenna. Further activity may comprise receiving signals by the receiving antenna disposed in a geological formation, the signals to be inverted to obtain at least one of resistivity or dielectric constant properties of the geological formation at a selected depth of investigation, the depth determined by the selection of the equivalent tilt angles and weighting with pre-computed integrated radial sensitivity signal data. Additional methods, apparatus, and systems are disclosed.

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: Disclosed are telemetry systems and methods that employ a plurality of electromagnetic transceivers disposed outside a well casing string at a corresponding plurality of depths along the casing string. Each transceiver includes one or more toroidal inductors circumferentially surrounding the casing string and inductively coupled thereto to allow signal transmission between transceivers via currents induced in the casing. In some embodiments, signals are relayed via a chain of transceivers to facilitate indirect communication between a surface facility and other transceivers located too deep for direct communication to the surface.

Abstract: Onshore electromagnetic (EM) reservoir monitoring systems and methods, including a system with a light source producing a light beam and an EM sensor array positioned above ground or buried underground over one or more regions of interest within a subterranean formation, the array coupled to the light source with an optical fiber. An EM sensor modulates the interrogation light beam in response to an EM signal induced into the subterranean formation by an EM source. The system further includes a processor controlling the light source, processing modulated light received from the array, and collecting data with the array to produce EM surveys, each EM survey based on data sets collected at different times. The EM sensor is physically isolated from a surrounding environment. The surveys are combined to produce a time lapse earth model of the regions of interest.

Abstract: An apparatus and method provides for nondestructive inspection of a generally tubular target structure (such as a wellbore casing) by rolling contact engagement of one or more rolling probe devices with the target structure. Each rolling probe device carries electromagnetic (EM) measurement instrumentation to capture measurement data during rolling contact engagement with the casing. Each rolling probe device may comprise an instrumentation carrier (e.g., a roller or a wheel) having an endless tread surface to engage the target structure, with the EM measurement instrumentation extending along the endless tread surface and being located at or adjacent an exterior of the instrumentation carrier. A plurality of such rolling instrumentation carriers can be mounted at azimuthally spaced positions on a tool body configured for axial movement along a wellbore.

Abstract: In some embodiments, an apparatus and a system, as well as a method and article of manufacture, may operate to parameterize a geological formation in terms of initial earth model parameters, and generate predicted data by simulating a tool response using earth model parameters. Further activity may include determining a difference between calibrated data and the predicted data; and simultaneously adjusting calibration parameters and the earth model parameters such that the difference between them satisfies selected convergence criteria, so that a controlled device can be operated according to at least one of updated calibration parameters, updated calibrated data, or updated earth model parameters. Additional apparatus, systems, and methods are disclosed.

Abstract: Various embodiments include apparatus and methods providing a tool to characterize a fracture in formation. Such a tool can use electromagnetic logging data that can be acquired in a processing unit to operate on the data using a fracture model that represents a fracture by an electrically thin sheet. Additional apparatus, systems, and methods are disclosed.

Abstract: Systems and methods to determine the status of transmitted audio packets. The audio packets can include digital components that are presented by a client computing device. Based on presentation variables and determinations of presentation status, the system can generate a predictive model that can be used to dynamically determines presentation values of audio packets prior to their transmission to a client computing device.

Abstract: Offshore electromagnetic (EM) reservoir monitoring systems and methods, including a system with a light source producing a light beam and an EM sensor array deployed at the bottom of a body of water and above one or more subsea regions of interest, the array coupled to the light source with an optical fiber. An EM sensor modulates the interrogation light beam in response to an EM signal induced into the subsea formation by an EM source. The system further includes a processor controlling the light source, processing modulated light received from the array, and collecting data with the array to produce EM surveys, each EM survey based on data sets collected at different times. The EM sensor is physically isolated from a surrounding subsea environment. The surveys are combined to produce a time lapse earth model of the regions of interest.

Abstract: A ranging system calculates the distance, direction and orientation of a target well through rotationally invariant analysis of triaxial electric and magnetic field measurements from a bottom hole assembly (“BHA”) having electromagnetic sensors. The triaxial electric and magnetic field sensors can be deployed in any downhole device without explicitly needing to process or retrieve rotational information about the downhole BHA or wireline device. Also, the distance, direction and orientation of the target well can be retrieved from a single measurement position.

Abstract: An illustrative casing coupler for a permanent electromagnetic (EM) monitoring system, the casing coupler includes a tubular body having threaded ends for connecting casing tubulars together, and a wire coil that encircles the tubular body and transmits and/or receives EM signals.

Abstract: Electromagnetic (EM) measurement systems and methods for a downhole environment are described herein. An example system includes an optical fiber, an EM source to emit an EM field, and a magnetic induction sensor. The magnetic induction sensor comprises a coil and an electro-optical transducer coupled to the coil and the optical fiber. The electro-optical transducer generates a light beam or modulates a source light beam in the optical fiber in accordance with a voltage induced in the coil by the EM field. An example method includes positioning an optical fiber and magnetic induction sensor in the downhole environment, the magnetic induction sensor having a coil and an electro-optical transducer coupled to the coil and the optical fiber. The method also includes emitting an EM field and generating a light beam or modulating a source light beam, by the electro-optical transducer, in the optical fiber in accordance with a voltage induced in the coil by the EM field.