Abstract: Methods and systems for performing injection treatments in subterranean formations stimulated by the ignition of propellants are provided. In some embodiments, the methods comprise: igniting a propellant in one or more secondary boreholes in a subterranean formation to at least partially rupture at least a region of the subterranean formation near the secondary boreholes; introducing a fracturing fluid into a first production well bore in the subterranean formation in or near the ruptured region of the subterranean formation at or above a pressure sufficient to create or enhance at least a primary fracture in the subterranean formation that extends into at least a portion of the ruptured region of the subterranean formation; and introducing a displacement fluid into one or more of the secondary boreholes or an injection well bore in the subterranean formation that comprises one or more fractures penetrating the ruptured region of the subterranean formation.

Abstract: A conductivity model is used for a logging tool and surrounding borehole and formation. The conductivity model is separable into a background conductivity model and an anomalous conductivity model for at least one of the formation and the tool. With the conductivity model, background electromagnetic fields and Green's functions corresponding to electromagnetic field signals at one or more receivers are computed for inversion of measured electromagnetic signals to determine adjustable parameters associated with anomalous conductivity. From the inversion, dielectric and other electromagnetic properties of the formation and borehole are determined.

Abstract: A ranging system using spatially continuous filtering techniques to constrain ranging measurements, thereby improving ranging calculations between a bottom-hole-assembly and at least one target well. By taking advantage of the spatial continuity of the wellbore geometry, a quality check of a ranging measurement is performed using ranging measurements acquired at prior depths. Thus, the methods described herein provide improved ranging and direction estimates, as well as prediction of ranging and direction of the target well ahead of the bottom-hole-as sembly.

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: Described are tools, systems, and methods for dielectric logging using transient waveforms. In some embodiments, one or more microstrip antennas are employed for the measurements. In various embodiments, the waveforms are processed in the time-domain to determine the dielectric properties of a formation, from which geophysical formation properties can then be derived. Further embodiments are disclosed.

Abstract: A logging system includes an electromagnetic logging tool that collects measurements of a subterranean formation as the tool is conveyed along a borehole through the formation. The system further includes a processing system that: generates a first plurality of models of the formation based on at least one first measurement of the formation, the at least one first measurement collected by the tool at a first location of a plurality of locations located along a drilling axis; generates a second plurality of models of the formation based on at least one second measurement of the formation, the at least one second measurement collected by the tool at a second location of the plurality of locations, wherein the second location is adjacent the first location; and selects a model of the first plurality of models based on a spatial continuity of the model with respect to the second plurality of models.

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: An offshore measured or logging-while drilling electromagnetic telemetry system includes a bottomhole assembly having a transmitter to communicate one or more electromagnetic telemetry signals. A subsea telemetry cable is positioned on a sea floor to receive the telemetry signals. The subsea telemetry cable is coupled to an umbilical cable extending to a surface communication unit positioned at the sea surface. Signals received by the subsea telemetry cable are transmitted to the surface communication unit for further processing.

Abstract: Methods, apparatus, and computer readable media are described herein for allowing a first user to interface with an automated assistant to assign tasks to additional user(s), and/or for causing notification(s) of the assigned task to be rendered to the additional user(s) via corresponding automated assistant interface(s). In various implementations, one or more criteria can be utilized in selecting a group of client device(s), linked to the additional user, via which to provide the notification(s) for the task assigned to the additional user. Also, in various implementations condition(s) for providing the notification(s) for the task can be determined, and the notification(s) provided based on determining satisfaction of the condition(s).

Abstract: In some embodiments, an apparatus and a system, as well as a method and article, may operate to model electromagnetic data to provide modeled electromagnetic data by solving a first set of surface integral equations that include earth model parameters corresponding to an earth model of a geological formation. Additional activity may include publishing at least some of the modeled electromagnetic data in human-readable form, and/or controlling drilling operations in the geological formation based on the earth model when error between the modeled electromagnetic data and measured electromagnetic data is less than a selected threshold. Additional apparatus, systems, and methods are disclosed.

Abstract: A magnetic field sensor unit for a downhole environment includes an optical fiber, a magnetic field sensor, and an optical transducer. The sensor unit also includes a sealed housing that encloses the magnetic field sensor and the optical transducer. The optical transducer is configured to generate a light beam or to modulate a source light beam in the optical fiber in response to a magnetic field sensed by the magnetic field sensor. Related magnetic field measurement methods and systems deploy one or more of such magnetic field sensor units in a downhole environment to obtain magnetic field measurements due to an emitted electromagnetic field.

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: 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.

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: 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: Disclosed are approaches to dielectric logging, and particularly to the processing of dielectric logging data, that involve the use of a conductivity model for the logging tool and surrounding borehole and formation that includes an anomalous conductivity model for the formation and/or a complex conductivity model of the tool. In accordance with various embodiments, the conductivity model is separated into background and anomalous portions, and background electromagnetic fields and Green's functions are computed from the background portions and thereafter used in the inversion of measured electromagnetic signals for adjustable parameters associated with the anomalous conductivity. Further embodiments are described.

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: A logging system includes an electromagnetic logging tool that collects measurements of a subterranean formation as the tool is conveyed along a borehole through the formation. The system further includes a processing system that: generates a first plurality of models of the formation based on at least one first measurement of the formation, the at least one first measurement collected by the tool at a first location of a plurality of locations located along a drilling axis; generates a second plurality of models of the formation based on at least one second measurement of the formation, the at least one second measurement collected by the tool at a second location of the plurality of locations, wherein the second location is adjacent the first location; and selects a model of the first plurality of models based on a spatial continuity of the model with respect to the second plurality of models.

Abstract: A wellbore ranging system and method utilized between first and second wellbores includes an electromagnetic field sensing instrument disposed in the second wellbore, a conductive casing in the first wellbore, an electric current source exciting current flow in the conductive member, and a fiber optic sensor disposed adjacent the conductive member. The current flow along the conductive member results in a magnetic field which is measured by the sensing instrument. The fiber optic sensor includes a core that is responsive to the magnetic field in which it is disposed. The responsive core alters the optical property of an optical wave guide forming the sensor, which altered optical property can be utilized to measure the magnitude of the electrical current at the position of the sensor. The magnitude of the current and the measured magnetic field can be utilized to determine a range between the first and second wellbores.

Abstract: Methods, systems, and computer program products appraise the quality of resistivity LWD data inversion and related earth models. The appraisal uses several quality factors, including signal-to-noise ratio, noise-to-signal ratio, data importance, model parameter importance, and model parameter confidence interval for the resistivity LWD data inversion and related earth models. These quality factors allow a user to determine which data provides useful information, which parts of the earth model may be relied upon, and conversely which parameters in which parts of the model may need to be modified. Such an arrangement is particularly useful in distance-to-bed-boundary (DTBB) inversion for geo-steering and formation evaluation.