Abstract: A method and system for identifying a target well. A system for identifying a target well may comprise placing an electromagnetic ranging tool in a wellbore, transmitting an electromagnetic field into a formation, inducing an eddy current within a target well, measuring a second electromagnetic field from the target well, calculating a position or an orientation of a transmitter or a receiver relative to another position, and calculating at least one parameter of the target well. An electromagnetic ranging system may comprise an electromagnetic ranging tool and an information handling system. The information handling system may be operable to calculate a position and/or an orientation of a transmitter or a receiver relative to another position on the electromagnetic ranging tool disposed on a borehole assembly, and calculate at least one parameter of a target well from the calculated position or orientation of the transmitter and the receiver.

Abstract: Aspects of the subject technology relate to systems and methods for identifying values of mud and formation parameters based on measurements gathered by an electromagnetic imager tool through machine learning. One or more regression functions that model mud and formation parameters capable of being identified through an electromagnetic imager tool as a function of possible tool measurements of the electromagnetic imager tool can be generated using a known dataset associated with the electromagnetic imager tool. One or more tool measurements obtained by the electromagnetic imager tool operating to log a wellbore can be gathered. As follows, one or more values of the mud and formation parameters can be identified by applying the one or more regression functions to the one or more tool measurements.

Abstract: Apparatus, systems, and methods may operate to detect anomalous formation resistivity values within measured formation resistivity data, based on mud resistivity associated with a borehole in a geological formation, the measured formation resistivity data comprising the anomalous formation resistivity values and acceptable formation resistivity values. Additional activity may include transforming the anomalous formation resistivity values into corrected formation resistivity values, inverting the corrected formation resistivity values and the acceptable formation resistivity values to provide true resistivity values for a geological formation, and operating a controlled device according to the true resistivity values for the geological formation. Additional apparatus, systems, and methods are disclosed.

Abstract: A method and system for resistivity imaging may comprise disposing a downhole tool into a borehole, wherein the downhole tool comprises a pad and a plurality of electrodes disposed on the pad, taking an impedance measurement with the plurality of electrodes, applying a correction to the measured impedance by using a relaxation constant of the measured impedance to find a corrected impedance for each electrode of the plurality of electrodes, and constructing an image from the corrected impedance, wherein the image maps formation impedance. The system for resistivity imaging may comprise a downhole tool, a conveyance for disposing the downhole tool in a borehole, and an information handling system. The downhole tool may further comprise an arm and a pad wherein the pad comprises a plurality of electrodes and at least one return electrode.

Abstract: In some embodiments, an apparatus and a system, as well as a method and an article, may operate to estimate a value for a mud cake parameter to provide an estimated mud cake parameter value; to generate, in a solution operation, a formation parameter value and an adjusted mud cake parameter value using the estimated mud cake parameter value; and to provide corrected galvanic tool resistivity measurements based on at least the adjusted mud cake parameter value. Additional apparatus, systems, and methods are disclosed.

Abstract: A method and system for estimating a mud angle. A method may comprise disposing a downhole tool into a borehole, energizing a button array, transmitting a current from the electrode into a formation, recording the current from the formation with a return electrode to obtain a plurality of measurements, identifying at least one low resistivity zone from the plurality of measurements to produce a measurement set, inverting the measurement set to find a mud angle vector, removing the mud angle vector from the measurement set to obtain a corrected measurement, and obtaining an electrical image using the corrected measurement. A system may comprise a downhole tool, a conveyance, and an information handling system. The downhole tool may further comprise at least one electrode and at least one return electrode.

Abstract: A method and system for resistivity imaging. A method may comprise disposing a downhole tool into a borehole, applying a voltage difference between the array of injector electrodes, constructing a first set of formation images for each of the plurality of frequencies, applying a mud effect removal algorithm to produce a second set of formation images for each of the plurality of frequencies, applying a dielectric correction algorithm to each of the plurality of frequencies to produce a third set of formation images for each of the plurality of frequencies, and combining the first set of formation images, the second set of formation images, and the third set of formation images to obtain a blended image. A system for resistivity imaging may comprise a downhole tool. The downhole tool may comprises a pad, an array of injector electrodes, and one or more return electrodes.

Abstract: A method and system for estimating a resistivity of a formation. A method for estimating a resistivity of a formation may comprise disposing a downhole tool into a borehole, wherein the downhole tool comprises a pad, an injector electrode, and a return electrode, injecting a current signal into the formation from the injector electrode, measuring a voltage signal between the injector electrode and the return electrode; and determining a formation resistivity and a formation dielectric constant from at least one of the voltage signal, at least one property of the downhole tool, and at least one property of the borehole. A system for estimating a resistivity of a formation may comprise a downhole tool. The downhole tool may comprise a pad, wherein the pad comprises an injector electrode and a return electrode. The system may further comprise a conveyance for disposing the downhole tool in a borehole and an information handling system.

Abstract: Methods and systems are described that can be used for locating conductive bodies such as wellbore casing or piping disposed below the earth's surface. An electrical current can be excited in a conductive body in each wellbore in a given area to produce a magnetic field, and the magnetic field can be detected by a ranging tool. Location and current parameters can be determined for an estimated number of wellbores producing non-negligible contributions to the magnetic field, and the estimated number of wellbores can be adjusted until the number of contributing wellbores is determined. Location solutions can be returned for each of the contributing wellbores, and the location solutions can be employed to facilitate exploration of drilling applications such as well avoidance, well intersection and/or steam assisted gravity drainage (SAGD) steering operations.

Abstract: A method and system for azimuthal direction detection of a cable. The method may comprise disposing an electromagnetic logging tool into a wellbore, transmitting a primary electromagnetic field from the one or more transmitters, recording one or more secondary electromagnetic fields at the one or more receivers, and identifying a direction to the cable from the one or more secondary electromagnetic fields. The system may comprise one or more transmitters disposed on the electromagnetic logging tool and configured to transmit a primary electromagnetic field. The system may further comprise one or more receivers disposed on the electromagnetic logging tool and configured to record one or more secondary electromagnetic fields. Additionally, the system may further comprise an information handling system configured to identify a direction to an azimuthally localized reduction in metal of the conductor or increase in the metal of the conductor from the secondary electromagnetic fields.

Abstract: Technology for obtaining formation parameters of a geological formation includes measuring a resistivity image of the geological formation. The measured resistivity image is compared to a modelled resistivity image where the modelled resistivity image is generated based on estimated formation parameters. A cost function is calculated based on the measure resistivity image and the modelled resistivity image. The estimated formation parameters are adjusted based on minimizing the cost function in order to generate a set of final formation parameters that represents a modelled resistivity image having a smallest cost function.

Abstract: Methods and systems are described that can be used for locating conductive bodies such as wellbore casing or piping disposed below the earth's surface. An electrical current can be excited in a conductive body in each wellbore in a given area to produce a magnetic field, and the magnetic field can be detected by a ranging tool. Location and current parameters can be determined for an estimated number of wellbores producing non-negligible contributions to the magnetic field, and the estimated number of wellbores can be adjusted until the number of contributing wellbores is determined. Location solutions can be returned for each of the contributing wellbores, and the location solutions can be employed to facilitate exploration of drilling applications such as well avoidance, well intersection and/or steam assisted gravity drainage (SAGD) steering operations.

Abstract: This disclosure may relate to a system and method for calculating the mud angle from a downhole device. A method for estimating a mud angle may comprise: disposing a downhole tool into a borehole; extending an arm of the downhole tool to a first location, wherein a pad is disposed on the arm; taking a first impedance measurement with at least one button electrode, wherein the button electrode is disposed in a button array, wherein the button array is disposed on the pad; extending the arm to a second location; taking a second impedance measurement with the at least one button electrode; transmitting the first measurement and the second measurement to an information handling system; and estimating the mud angle from the first impedance measurement and the second impedance measurement with an information handling system.

Abstract: A method and a system for estimating a pipe property for a plurality of nested pipes. The method may comprise determining the pipe property from the plurality of measurements, wherein the pipe property identifies a feature in the wellbore, forming a pre-computed table of responses for the at least one channel comprising a plurality of points that sample the pipe property, and performing a model-based inversion to estimate the pipe property using the plurality of measurements, the nominal properties of the pipes, and a fast forward model based on the pre-computed table of responses. A system may comprise an electromagnetic logging tool and an information handling system. The electromagnetic logging tool may comprise a transmitter, wherein the transmitter is a first coil and is operable to transmit an electromagnetic field, and a receiver, wherein the receiver and is operable to measure the electromagnetic field.

Abstract: Apparatus and methods to visualize formation properties and distances associated with formations can be implemented in a variety of applications. In various embodiments, one or more visualization schemes and systems arranged to implement such schemes can use a combination of visual structures to provide information about measured formations. Additional apparatus, systems, and methods are disclosed.

Abstract: Eddy current logging enables corrosion monitoring in nested-pipe arrangements. An illustrative method of logging total thickness of the pipe walls includes acquiring measurements from an electromagnetic logging tool conveyed through the innermost bore, each measurement associated with a TRF combination (transmit antenna, receive antenna, and frequency), and further associated with a position along the bore. Multiple scale factors are applied to the measurements to determine multiple total thickness estimates for each position, each of the multiple scale factors corresponding to a subset of single-pipe defect profiles. Preferably, every possible single-pipe defect profile is included in at least one of these subsets. A total thickness log value for each position is derived from the multiple total thickness estimates for that position, and the derived total thickness log values are used to update a displayed total thickness log as the measurements are being acquired.

Abstract: Eddy current logging enables corrosion monitoring in nested-pipe arrangements. An illustrative method of logging total thickness of the pipe walls includes acquiring measurements from an electromagnetic logging tool conveyed through the innermost bore, each measurement associated with a TRF combination (transmit antenna, receive antenna, and frequency), and further associated with a position along the bore. Multiple scale factors are applied to the measurements to determine multiple total thickness estimates for each position, each of the multiple scale factors corresponding to a subset of single-pipe defect profiles. Preferably, every possible single-pipe defect profile is included in at least one of these subsets. A total thickness log value for each position is derived from the multiple total thickness estimates for that position, and the derived total thickness log values are used to update a displayed total thickness log as the measurements are being acquired.

Abstract: A variety of methods and systems are disclosed, including, a method for improving resistivity imaging, comprising: disposing a downhole tool into a borehole, wherein the downhole tool comprises a pad and a button array disposed on the pad; taking a measurement with the button array at a location in the borehole; selecting a projection angle; obtaining a corrected measurement from the projection angle and the measurement; and constructing an image using the corrected measurement. A system for improving resistivity imaging, comprising: a downhole tool, wherein the downhole tool comprises: an arm, and a pad; a conveyance; and an information handling system, wherein the information handling system is configured to take a measurement with the button array at a location in the borehole; select a projection angle; obtain a corrected measurement from the projection angle and the measurement; and construct an image using the corrected measurement.

Abstract: A ranging system utilizes gradiometric data to determine the direction to and distance between a first and second well without any knowledge or involvement of the borehole or formation characteristics in order to intersect and/or avoid the second well. In general, this is achieved by deploying a downhole assembly comprising transmitters and receivers having magnetic dipoles, along with bucking receivers positioned between the transmitters and receivers.

Abstract: Planning and real time optimization of one or more modules of a downhole tool provide efficient and cost-effective deployment of a measurement system, for example, for a ranging tool. Considerations of the environment and type of operation may be considered prior to the deployment of a downhole tool such that the downhole tool comprises modules that may be optimized. Certain modules may be activated for specific operations without having to extract the downhole tool as all modules necessary to perform the specific tasks for a given operation are included prior to deployment of the downhole tool. The one or more modules may be optimized in real time based, for example, on received measurements or previous survey results. The modularity of the downhole tool allows for flexibility in fine tuning the tool according to a varying formation environment and other parameters.