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: Aspects of the subject technology relate to systems and methods for controlling a hydraulic fracturing job. One or more perforations to create during a fracturing stage of a fracturing job at one or more corresponding perforation sites in a wellbore can be identified. The one or more perforations can be formed through one or more perforation devices disposed in the wellbore. Specifically, the one or more perforation devices can be selectively activated from a surface of the wellbore through a well intervention-less technique to selectively form the one or more perforations during the fracturing stage. Further, a volume of fracturing fluid can be pumped into the wellbore during the fracturing stage to form one or more first fractures in a surrounding formation through the one or more perforations.

Abstract: Systems and methods are provided for applying a protective graphene barrier to waveguides and using the protected waveguides in wellbore applications. A well monitoring system may comprise a waveguide comprising a graphene barrier, wherein the graphene barrier comprises at least one material selected from the group consisting of graphene, graphene oxide, and any combination thereof; a signal generator capable of generating a signal that travels through the waveguide; and a signal detector capable of detecting a signal that travels through the waveguide.

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: 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: Aspects of the subject technology relate to systems and methods for controlling a hydraulic fracturing job. One or more perforations to create during a fracturing stage of a fracturing job at one or more corresponding perforation sites in a wellbore can be identified. The one or more perforations can be formed through one or more perforation devices disposed in the wellbore. Specifically, the one or more perforation devices can be selectively activated from a surface of the wellbore through a well intervention-less technique to selectively form the one or more perforations during the fracturing stage. Further, a volume of fracturing fluid can be pumped into the wellbore during the fracturing stage to form one or more first fractures in a surrounding formation through the one or more perforations.

Abstract: Systems and methods for noise cancellation in electromagnetic telemetry systems. A method for noise cancellation in electromagnetic telemetry may include: disposing an electromagnetic tool in a lateral section of a wellbore, wherein the electromagnetic tool comprises a transmitter; positioning a first counter electrode at a surface of the Earth; positioning a second counter electrode at the surface on an opposite side of the wellbore from the lateral section; transmitting a signal from the electromagnetic tool; measuring a first electromagnetic field property using the first counter electrode to obtain a received voltage; measuring a second electromagnetic field property using the second counter electrode to obtain a noise voltage; and removing noise from received voltage using the noise voltage.

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: Systems and methods that relate to monitoring a subterranean formation using casing centralizers. A system for well monitoring comprising: a casing centralizer comprising arms configured to contact a wellbore when the casing centralizer is installed in a wellbore; and a receiver coupled to the casing centralizer and configured to measure an electrical magnitude of a current injected into a subterranean formation through the arms of the casing centralizer.

Abstract: A formation monitoring system includes a casing that defines an annular space within a borehole. A distributed magnetomotive force sensor is positioned in the annular space and configured to communicate with the surface via a fiber-optic cable. A computer coupled to the fiber-optic cable receives measurements and responsively derives the location of any fluid fronts in the vicinity such as an approaching flood front to enable corrective action before breakthrough. A formation monitoring method includes: injecting a first fluid into a reservoir formation; producing a second fluid from the reservoir formation via a casing in a borehole; collecting magnetic field measurements with a distributed magnetomotive force sensor in an annular space between the casing and the borehole, communicating measurements to a surface interface via one or more fiber-optic cables; and operating on the measurements to locate a front between the first and second fluids.

Abstract: Systems and methods for noise cancellation in electromagnetic telemetry systems. A method for noise cancellation in electromagnetic telemetry may include: disposing an electromagnetic tool in a lateral section of a wellbore, wherein the electromagnetic tool comprises a transmitter; positioning a first counter electrode at a surface of the Earth; positioning a second counter electrode at the surface on an opposite side of the wellbore from the lateral section; transmitting a signal from the electromagnetic tool; measuring a first electromagnetic field property using the first counter electrode to obtain a received voltage; measuring a second electromagnetic field property using the second counter electrode to obtain a noise voltage; and removing noise from received voltage using the noise voltage.

Abstract: A method of optical communication in a well can include launching light having substantially coherent phase into an optical waveguide extending in a wellbore, modulating light having substantially coherent phase in the wellbore, and receiving the modulated light transmitted via the same optical waveguide. A well system can include at least one optical waveguide extending in a wellbore, and a downhole optical modulator which modulates light transmitted via the optical waveguide, the optical modulator comprising a potassium titanyl phosphate crystal. Another method of optical communication in a well can include launching light into an optical waveguide extending in a wellbore, the light launched into the optical waveguide having information modulated thereon using a carrier, modulating light in the wellbore, the modulating comprising modulating information using a subcarrier of the carrier, and transmitting the light modulated in the wellbore via the same optical waveguide.

Abstract: A method of logging a well can include conveying an optical waveguide and at least one signal generator with a conveyance into the well, causing the signal generator to generate at least one signal in the well, and receiving the signal as distributed along the optical waveguide. A well logging system can include a conveyance with an optical waveguide, and at least one signal generator which is conveyed by the conveyance into a well with the optical waveguide, whereby the signal generator generates at least one signal received with the optical waveguide.

Abstract: A disclosed subsurface electromagnetic field monitoring system includes at least one fiberoptic cable to optically communicate measurements from an array of electromagnetic field sensors in a borehole. The array of electromagnetic field sensors includes a distributed feedback fiber laser strain sensor with electromagnetic field sensitivity.

Abstract: A well tool can include an outer housing and a vibratory transmitter disposed in the outer housing. The vibratory transmitter transmits a vibratory signal to an optical line disposed in the outer housing. A well system can include an optical line extending in a wellbore, and at least one well tool secured to the optical line and including a vibratory transmitter which transmits a vibratory signal to the optical line. The optical line conveys the well tool into the wellbore. A method of telemetering data from a well tool to an optical line can include securing the well tool to the optical line without optically connecting the well tool to the optical line, and conveying the well tool in a wellbore on the optical line.

Abstract: An optical link including an optical computing device having an integrated computational element (ICE), and a method for using the device to perform a remote measurement of a characteristic of a sample with the optical computing device are provided. The optical computing device provides an optical computing signal proportional to a characteristic of a sample from an interacted light provided to the ICE. The device includes an optical transducer to provide a modulating signal based on the optical computing signal and a modulator to modulate a first portion of a transmission light in an optical waveguide based on the modulating signal.

Abstract: A disclosed system for determining sources of water in a downhole fluid includes one or more downhole sensors that measure at least one analyte concentration in the downhole fluid, and a computer having analyte concentration characteristics for water from multiple sources. The computer uses the analyte concentration characteristics and the at least one analyte concentration measurement to determine an amount of water from at least one given source. A described method for determining sources of water in a downhole fluid includes associating with each of multiple sources of water a characteristic concentration of at least one analyte, obtaining measured concentrations of the at least one analyte with one or more downhole sensors, and deriving for at least one source of water a fraction of the downhole fluid attributable to that at least one source. The deriving may also be based upon measurements from distributed pressure and/or temperature sensors.

Abstract: A disclosed formation monitoring system includes a casing that defines an annular space within a borehole. A distributed magnetomotive force sensor is positioned in the annular space and configured to communicate with the surface via a fiber-optic cable. A computer coupled to the fiber-optic cable receives said measurements and responsively derives the location of any fluid fronts in the vicinity such as a an approaching flood front to enable corrective action before breakthrough. A disclosed formation monitoring method includes: injecting a first fluid into a reservoir formation; producing a second fluid from the reservoir formation via a casing in a borehole; collecting magnetic field measurements with a distributed magnetomotive force sensor in an annular space between said casing and said borehole, communicating measurements to a surface interface via one or more fiber-optic cables; and operating on said measurements to locate a front between the first and second fluids.

Abstract: Systems and methods for formation evaluation and reservoir monitoring that use electromotive force measurements. A well monitoring system may comprise: a power supply that generates an electromagnetic field in a subterranean formation; and a distributed electromotive force sensor for measuring electromotive force at one or more points along a length of the distributed electromotive sensor, wherein the distributed electromotive force sensor comprises an optical waveguide and an electro-optical transducing layer coated on one or more lengths of the optical waveguide.

Abstract: Systems and methods that relate to monitoring a subterranean formation using casing centralizers. A system for well monitoring comprising: a casing centralizer comprising arms configured to contact a wellbore when the casing centralizer is installed in a wellbore; and a receiver coupled to the casing centralizer and configured to measure an electrical magnitude of a current injected into a subterranean formation through the arms of the casing centralizer.