Abstract: Systems and methods of the disclosed embodiments include a rheometer having a housing with a fluid inlet and a fluid outlet, a cylinder with a cavity located to receive fluid that passes into the fluid inlet, a motor configured to rotate the cylinder, a torsion bob within the cavity, and a controller located remotely from the rheometer. The controller includes a pressure regulator configured to pressurize fluid to power the motor, a rotation sensor configured to receive an optical rotation signal indicating a rotation speed of the cylinder, and a torque sensor configured to receive an optical signal indicating a torque on the torsion bob. The controller may be configured to receive a rotation speed signal from the rotation sensor, a torque signal from the torque sensor, and to calculate a shear stress for the fluid based on the rotation speed signal and the torque signal.

Abstract: A telemetry system is disclosed for use in a wellbore extending from the surface. The telemetry system includes fiber optic cable locatable in the wellbore, the fiber optic cable including at least one optical fiber. The telemetry system also includes a telemetry device operable to transmit an optical telemetry signal over the fiber optic cable. An optical detector operably connected to the optical fiber and includes a single-photon detector operable to receive the optical telemetry signal transmitted over the optical fiber.

Abstract: A distributed acoustic system (DAS) method and system. The system may comprise an interrogator and an umbilical line comprising a first fiber optic cable and a second fiber optic cable attached at one end to the interrogator. The DAS may further include a downhole fiber attached to the umbilical line at the end opposite the interrogator and a light source disposed in the interrogator that is configured to emit a plurality of coherent light frequencies into the umbilical line and the downhole fiber. The method may include generating interferometric signals of the plurality of frequencies of backscattered light that have been received by the photo detector assembly and processing the interferometric signals with an information handling system.

Abstract: A telemetry system is disclosed for use in a wellbore extending from the surface. The telemetry system includes fiber optic cable locatable in the wellbore, the fiber optic cable including at least one optical fiber. The telemetry system also includes a telemetry device operable to transmit an optical telemetry signal over the fiber optic cable. An optical detector operably connected to the optical fiber and includes a single-photon detector operable to receive the optical telemetry signal transmitted over the optical fiber.

Abstract: A distributed acoustic system (DAS) method and system. The system may comprise an interrogator and an umbilical line comprising a first fiber optic cable and a second fiber optic cable attached at one end to the interrogator. The DAS may further include a downhole fiber attached to the umbilical line at the end opposite the interrogator and a light source disposed in the interrogator that is configured to emit a plurality of coherent light frequencies into the umbilical line and the downhole fiber. The method may include generating interferometric signals of the plurality of frequencies of backscattered light that have been received by the photo detector assembly and processing the interferometric signals with an information handling system.

Abstract: A system includes an optical fiber integrated into a conveyance subsystem that is positionable downhole in a wellbore. The system also includes a backscattering sensor system positionable to monitor temperature and optical fiber strain along the optical fiber using backscattered light signals received from the optical fiber. Further, the system includes a fiber optic rotary joint positionable to optically couple the optical fiber with the backscattering sensor system to provide an optical path for the backscattered light signals to reach the backscattering sensor system.

Abstract: Systems and methods of the disclosed embodiments include a rheometer having a housing with a fluid inlet and a fluid outlet, a cylinder with a cavity located to receive fluid that passes into the fluid inlet, a motor configured to rotate the cylinder, a torsion bob within the cavity, and a controller located remotely from the rheometer. The controller includes a pressure regulator configured to pressurize fluid to power the motor, a rotation sensor configured to receive an optical rotation signal indicating a rotation speed of the cylinder, and a torque sensor configured to receive an optical signal indicating a torque on the torsion bob. The controller may be configured to receive a rotation speed signal from the rotation sensor, a torque signal from the torque sensor, and to calculate a shear stress for the fluid based on the rotation speed signal and the torque signal.

Abstract: A distributed acoustic system (DAS) method and system. The system may comprise an interrogator and an umbilical line comprising a first fiber optic cable and a second fiber optic cable attached at one end to the interrogator. The DAS may further include a downhole fiber attached to the umbilical line at the end opposite the interrogator and a light source disposed in the interrogator that is configured to emit a plurality of coherent light frequencies into the umbilical line and the downhole fiber. The method may include generating interferometric signals of the plurality of frequencies of backscattered light that have been received by the photo detector assembly and processing the interferometric signals with an information handling system.

Abstract: A distributed acoustic system (DAS) with an interrogator, an umbilical line attached at one end to the interrogator, and a downhole fiber attached to the umbilical line at the end opposite the interrogator. A method for optimizing a sampling frequency may begin with identifying a length of a fiber optic cable connected to an interrogator, identifying one or more regions on the fiber optic cable in which a backscatter is received, and optimizing a sampling frequency of a distributed acoustic system (DAS) by identifying a minimum time interval that is between an emission of a light pulse such that at no point in time the backscatter arrives back at the interrogator that corresponds to more than one spatial location along a sensing portion of the fiber optic cable.

Abstract: A system includes an optical fiber integrated into a conveyance subsystem that is positionable downhole in a wellbore. The system also includes a backscattering sensor system positionable to monitor temperature and optical fiber strain along the optical fiber using backscattered light signals received from the optical fiber. Further, the system includes a fiber optic rotary joint positionable to optically couple the optical fiber with the backscattering sensor system to provide an optical path for the backscattered light signals to reach the backscattering sensor system.

Abstract: A distributed acoustic system (DAS) with an interrogator, an umbilical line attached at one end to the interrogator, and a downhole fiber attached to the umbilical line at the end opposite the interrogator. A method for optimizing a sampling frequency may begin with identifying a length of a fiber optic cable connected to an interrogator, identifying one or more regions on the fiber optic cable in which a backscatter is received, and optimizing a sampling frequency of a distributed acoustic system (DAS) by identifying a minimum time interval that is between an emission of a light pulse such that at no point in time the backscatter arrives back at the interrogator that corresponds to more than one spatial location along a sensing portion of the fiber optic cable.

Abstract: A borehole fluid imaging system includes a plurality of radiation sources located circumferentially around the borehole. A plurality of radiation detectors are located circumferentially around the borehole. The plurality of radiation detectors detect the radiation transmitted by each of the respective ones of the plurality of radiation sources. A controller is coupled to the plurality of radiation detectors to determine an attenuation of the radiation at the plurality of detectors and generate an image of the fluid in response to the attenuation of the radiation.

Abstract: A borehole fluid imaging system includes a plurality of radiation sources located circumferentially around the borehole. A plurality of radiation detectors are located circumferentially around the borehole. The plurality of radiation detectors detect the radiation transmitted by each of the respective ones of the plurality of radiation sources. A controller is coupled to the plurality of radiation detectors to determine an attenuation of the radiation at the plurality of detectors and generate an image of the fluid in response to the attenuation of the radiation.

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 system may include a sensor to detect a characteristic of a fluid and output an electrical signal proportional to the characteristic, an acoustic signal generator to output an acoustic signal proportional to the electrical signal, and a signal detection apparatus to generate a signal proportional to the acoustic signal and transmit the signal to a remote location.

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 flowing fluid from a formation, the method comprising: sensing presence of a reservoir impairing substance in the fluid flowed from the formation; and automatically controlling operation of at least one flow control device in response to the sensing of the presence of the substance. A well system, comprising: at least one sensor which senses whether a reservoir impairing substance is present; and at least one flow control device which regulates flow of a fluid from a formation in response to indications provided by the sensor.

Abstract: A side-hole optical cane for measuring pressure and/or temperature is disclosed. The side-hole cane has a light guiding core containing a sensor and a cladding containing symmetrical side-holes extending substantially parallel to the core. The side-holes cause an asymmetric stress across the core of the sensor creating a birefringent sensor. The sensor, preferably a Bragg grating, reflects a first and second wavelength each associated with orthogonal polarization vectors, wherein the degree of separation between the two is proportional to the pressure exerted on the core. The side-hole cane structure self-compensates and is insensitive to temperature variations when used as a pressure sensor, because temperature induces an equal shift in both the first and second wavelengths. Furthermore, the magnitude of these shifts can be monitored to deduce temperature, hence providing the side-hole cane additional temperature sensing capability that is unaffected by pressure.

Abstract: A downhole optical sensor system includes at least one optical sensor positioned in a borehole and coupled to an interface via a fiber optic cable. Each of the optical sensors includes a waveguide for conducting light, and a reagent region positioned between the waveguide and a fluid in the borehole to absorb a portion of the light from the waveguide, the portion being dependent upon a concentration of a chemical species in the fluid. A method for operating a well includes deploying one or more downhole optical sensors in a fluid flow path in the well, probing the one or more downhole optical sensors from a surface interface to detect concentrations of one or more chemical species, and deriving a rate of scale buildup or corrosion based at least in part on the detected concentrations.