Abstract: Distributed sensing systems and methods with spatial location correlation of a reflection produced along an electromagnetic (EM) waveguide. A distributed sensing system comprises an EM waveguide, a distributed sensing interrogator, and a processor. The distributed sensing interrogator comprises a transmitter coupled to the EM waveguide and generates an interrogation pulse through the EM waveguide. The distributed sensing interrogator also comprises a receiver coupled to the EM waveguide and responsive to backscattered EM waves propagating through the EM waveguide. The processor determines a spatial location associated with a reflection produced along the EM waveguide using a return signal generated from the reflection by the interrogator and an interrogation signal including the interrogation pulse.

Abstract: A device including an ion-selective membrane arranged within an optical path of the device and coupled to a sample cell to interact with a fluid sample and thereby modify an optical response of the ion-selective membrane according to an ion concentration in the fluid sample, is provided. The device also includes an integrated computational element (ICE) arranged within the optical path, so that the illumination light optically interacts with the ICE and with the ion-selective membrane to provide a modified light that has a property indicative of the ion concentration in the fluid sample. A detector that receives the modified light provides an electrical signal proportional to the property of the modified light. A method and a system for using the above device are also provided.

Abstract: A device including an ion-selective membrane arranged within an optical path of the device and coupled to a sample cell to interact with a fluid sample and thereby modify an optical response of the ion-selective membrane according to an ion concentration in the fluid sample, is provided. The device also includes an integrated computational element (ICE) arranged within the optical path, so that the illumination light optically interacts with the ICE and with the ion-selective membrane to provide a modified light that has a property indicative of the ion concentration in the fluid sample. A detector that receives the modified light provides an electrical signal proportional to the property of the modified light. A method and a system for using the above device are also provided.

Abstract: A device including an ion-selective membrane arranged within an optical path of the device and coupled to a sample cell to interact with a fluid sample and thereby modify an optical response of the ion-selective membrane according to an ion con-centration in the fluid sample, is provided. The device also includes an integrated computational element (ICE) arranged within the optical path, so that the illumination light optically interacts with the ICE and with the ion-selective membrane to provide a modified light that has a property indicative of the ion concentration in the fluid sample. A detector that receives the modified light provides an electrical signal proportional to the property of the modified light. A method and a system for using the above device are also provided.

Abstract: Distributed sensing systems and methods with spatial location correlation of a reflection produced along an electromagnetic (EM) waveguide. A distributed sensing system comprises an EM waveguide, a distributed sensing interrogator, and a processor. The distributed sensing interrogator comprises a transmitter coupled to the EM waveguide and generates an interrogation pulse through the EM waveguide. The distributed sensing interrogator also comprises a receiver coupled to the EM waveguide and responsive to backscattered EM waves propagating through the EM waveguide. The processor determines a spatial location associated with a reflection produced along the EM waveguide using a return signal generated from the reflection by the interrogator and an interrogation signal including the interrogation pulse.

Abstract: Systems and methods for measuring a characteristic of a fluid are provided. The system includes a plurality of waveguides embedded in a substrate, and an exposed surface of the substrate comprising a portion of a side surface of at least one of the plurality of waveguides. The system also includes a sensitized coating in the at least one of the plurality of waveguides. The exposed surface is curved in a direction perpendicular to a light propagation in the waveguide. A method of fabricating a system as above is also provided.

Abstract: Optical sensors having one or more soluble coatings thereon are used to detect the presence of a degrading fluid. In a generalized embodiment, the fiber optic sensor includes a fiber optic cable having two strain sensor positioned therein. A soluble layer is positioned over one of the strain sensor. Due to the presence of the soluble layer, the covered strain sensor optically responds differently than the other strain sensor to changes in pressure, strain and temperature. In the presence of a degrading fluid, the soluble layer degrades and ultimately dissolves, thereby changing the optical response of the previously covered strain sensor. When the soluble layer is dissolved, the strain induced by the soluble layer relaxes, thus causing a wavelength shift in the signal of the grating. By monitoring the wavelength shifts of both strain sensors, the fiber optic sensor acts as a detector for the presence of the degrading fluid.

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 method of monitoring a substance includes optically interacting at least one birefringent integrated computational element with at least the substance and a polarizer, thereby generating optically interacted light. The polarizer is being configured to generate at least x polarized light and y polarized light. The method includes receiving the optically interacted light with at least one detector. The method includes generating with the at least one detector output signals corresponding to at least two characteristics of the substance.

Abstract: Purging of fiber optic conduits in subterranean wells. A downhole optical sensing system includes an optical line, at least two tubular conduits, one conduit being positioned within the other conduit, and the optical line being positioned within at least one of the conduits, and a purging medium flowed in one direction through one conduit, and flowed in an opposite direction between the conduits. A method of purging a downhole optical sensing system includes the steps of: installing at least two conduits and an optical line in a well as part of the sensing system, one conduit being positioned within the other conduit, and the optical line being positioned within at least one of the conduits; and flowing a purging medium through the conduits in the well, so that the purging medium flows in one direction through one conduit and in an opposite direction between the conduits.

Abstract: A position determination system and a method for position detection within a wellbore are disclosed. A radioactive tag may be disposed within the wellbore. One or more scintillating optical fibers may be longitudinally disposed along a drill string, wireline, or the like, and run into the wellbore. A detector system is coupled to the optical fiber(s). A scintillating optical fiber emits short, bright flashes of visible light whenever exposed to the gamma radiation. When a scintillating flash is measured, it may be determined that the optical fiber is located within proximity to the radioactive tag. The amplitude of received pulses may be used to estimate where in the optical fiber scintillating events are occurring. By providing a second optical fiber coupled to a scintillating optical fiber, a time delay between received pulses may be used to indicate where along the scintillating optical fiber scintillation events are occurring.

Abstract: A well tool actuator can include a series of chambers which, when opened in succession, cause the well tool to be alternately actuated. A method of operating a well tool actuator can include manipulating an object in a wellbore; a sensor of the actuator detecting the object manipulation; and the actuator actuating in response to the sensor detecting the object manipulation. A drilling isolation valve can comprise an actuator including a series of chambers which, when opened in succession, cause the isolation valve to be alternately opened and closed. A method of operating a drilling isolation valve can include manipulating an object in a wellbore, a sensor of the drilling isolation valve detecting the object manipulation, and the drilling isolation valve operating between open and closed configurations in response to the sensor detecting the object manipulation.

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: A gaseous fuel monitoring system can include a gaseous fuel supply enclosure, an optical line extending along the gaseous fuel supply enclosure, and a relatively highly thermally conductive material contacting both the gaseous fuel supply enclosure and the optical line. The relatively highly thermally conductive material can comprise a pyrolytic carbon material. A method of detecting leakage from a gaseous fuel supply enclosure can include securing an optical line to the gaseous fuel supply enclosure, the securing comprising contacting a pyrolytic carbon material with the optical line and the gaseous fuel supply enclosure. A gaseous fuel monitoring system can include an optical interrogator connected to the optical line, which interrogator detects changes in light transmitted by the optical line due to changes in vibrations of the enclosure.

Abstract: Systems and methods for measuring a characteristic of a fluid are provided. The system includes a plurality of waveguides embedded in a substrate, and an exposed surface of the substrate comprising a portion of a side surface of at least one of the plurality of waveguides. The system also includes a sensitized coating in the at least one of the plurality of waveguides. The exposed surface is curved in a direction perpendicular to a light propagation in the waveguide. A method of fabricating a system as above is also provided.

Abstract: A device including an ion-selective membrane arranged within an optical path of the device and coupled to a sample cell to interact with a fluid sample and thereby modify an optical response of the ion-selective membrane according to an ion con-centration in the fluid sample, is provided. The device also includes an integrated computational element (ICE) arranged within the optical path, so that the illumination light optically interacts with the ICE and with the ion-selective membrane to provide a modified light that has a property indicative of the ion concentration in the fluid sample. A detector that receives the modified light provides an electrical signal proportional to the property of the modified light. A method and a system for using the above device are also provided.

Abstract: Systems and methods for measuring a characteristic of a fluid are provided. The system includes a plurality of waveguides embedded in a substrate, and an exposed surface of the substrate comprising a portion of a side surface of at least one of the plurality of waveguides. The system also includes a sensitized coating in the at least one of the plurality of waveguides. The exposed surface is curved in a direction perpendicular to a light propagation in the waveguide. A method of fabricating a system as above is also provided.

Abstract: Optical sensors having one or more soluble coatings thereon are used to detect the presence of a degrading fluid. In a generalized embodiment, the fiber optic sensor includes a fiber optic cable having two strain sensor positioned therein. A soluble layer is positioned over one of the strain sensor. Due to the presence of the soluble layer, the covered strain sensor optically responds differently than the other strain sensor to changes in pressure, strain and temperature. In the presence of a degrading fluid, the soluble layer degrades and ultimately dissolves, thereby changing the optical response of the previously covered strain sensor. When the soluble layer is dissolved, the strain induced by the soluble layer relaxes, thus causing a wavelength shift in the signal of the grating. By monitoring the wavelength shifts of both strain sensors, the fiber optic sensor acts as a detector for the presence of the degrading fluid.

Abstract: A position determination system and a method for position detection within a wellbore are disclosed. A radioactive tag may be disposed within the wellbore. One or more scintillating optical fibers may be longitudinally disposed along a drill string, wireline, or the like, and run into the wellbore. A detector system is coupled to the optical fiber(s). A scintillating optical fiber emits short, bright flashes of visible light whenever exposed to the gamma radiation. When a scintillating flash is measured, it may be determined that the optical fiber is located within proximity to the radioactive tag. The amplitude of received pulses may be used to estimate where in the optical fiber scintillating events are occurring. By providing a second optical fiber coupled to a scintillating optical fiber, a time delay between received pulses may be used to indicate where along the scintillating optical fiber scintillation events are occurring.

Abstract: A method and device for monitoring oil field operations with a fiber optic distributed acoustic sensor (DAS) that uses a continuous wave laser light source and modulates the continuous wave output of the laser light source with pseudo-random binary sequence codes.