Abstract: A well system includes a fiber-optic cable positionable downhole along a length of a wellbore. The well system further includes an opto-electrical interface to communicatively couple to the fiber-optic cable to monitor a gas released from a well element within the wellbore. Further, the well system includes a processing device and a memory device that includes instructions executable by the processing device. The instructions cause the processing device to detect hydrogen absorption by the fiber-optic cable within the wellbore and determining a location of deterioration of the well element using the detected hydrogen absorption by the fiber-optic cable.

Abstract: A well system includes a fiber-optic cable positionable downhole along a length of a wellbore. The well system further includes an opto-electrical interface to communicatively couple to the fiber-optic cable to monitor a gas released from a well element within the wellbore. Further, the well system includes a processing device and a memory device that includes instructions executable by the processing device. The instructions cause the processing device to detect hydrogen absorption by the fiber-optic cable within the wellbore and determining a location of deterioration of the well element using the detected hydrogen absorption by the fiber-optic cable.

Abstract: A fiber optic sensor interrogation system with inbuilt passive power limiting capability based on stimulated Brillouin scattering that provides improved safety performance for use in explosive atmospheres.

Abstract: Various embodiments include apparatus and methods to measure a parameter of interest using a fiber optic cable. The parameters can be provided by a process that provides for multiplexed or distributed measurements. A multiplexed or a distributed architecture can include acoustic sensor units placed selectively along an optical fiber such that the acoustic sensor units effectively modulate the optical fiber with information regarding a parameter to provide the information to an interrogator coupled to the optical fiber that is separate from the acoustic sensor units.

Abstract: A fiber optic sensor interrogation system with inbuilt passive power limiting capability based on stimulated Brillouin scattering that provides improved safety performance for use in explosive atmospheres.

Abstract: Various embodiments include apparatus and methods to measure a parameter of interest using a fiber optic cable. The parameters can be provided by a process that provides for multiplexed or distributed measurements. A multiplexed or a distributed architecture can include acoustic sensor units placed selectively along an optical fiber such that the acoustic sensor units effectively modulate the optical fiber with information regarding a parameter to provide the information to an interrogator coupled to the optical fiber that is separate from the acoustic sensor units.

Abstract: Various embodiments include systems and methods to communicate along pipes using a conductive waveguide at quasioptical frequencies. The communication can be conducted as propagation to and from a tool at the quasioptical frequencies. A communication architecture may include a transmitter and receiver at one end of the conductive waveguide and a modulation device at an opposite end of the conductive waveguide. Additional systems and methods are disclosed.

Abstract: A deep water subsea tree completion having a distributed temperature sensing system. In a described embodiment, a method of installing an optical fiber in a well includes the steps of: conveying an optical fiber section into the well; and monitoring a light transmission quality of the optical fiber section while the section is being conveyed into the well.

Abstract: A fiber optic conduit for use in a hostile environment includes an axial tube. The axial tube comprises a corrosion resistant material and is operable to receive one or more optical fibers. The fiber optic conduit further includes a hydrogen barrier shell that is disposed in contact with the axial tube. The hydrogen barrier shell comprises a material that is capable of reducing hydrogen permeation through the fiber optic conduit and has a thickness of at least approximately one-thousandth of an inch.

Abstract: A fiber optic conduit for use in a hostile environment includes a hydrogen barrier shell that is disposed outwardly from an inner axial tube. The hydrogen barrier shell comprises a material that is capable of reducing hydrogen permeation through the fiber optic conduit and a thickness of at least approximately one-thousandth of an inch. The inner axial tube is operable to receive one or more optical fibers. The conduit further includes an outer axial tube that is disposed outwardly from the hydrogen barrier shell and is operable to form a hydrostatic pressure boundary for the fiber optic conduit.

Abstract: A fiber optic splice housing and integral dry mate connector system. In a described embodiment, a fiber optic connection system includes optical fiber sections in respective conduit sections. Each of the conduit sections is received in the housing assembly. An optical connection between the optical fiber sections is positioned within the housing assembly.

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: In an interferometric sensing apparatus, a scrambler is positioned in front of a polarizer, followed by a detector. In that way, although the two beams remain orthogonal to each other, they are continuously rotated, relative to the polarizer. In some positions, both beams pass through the polarizer and interfere, thus eliminating polarization fading. The signal is amplitude modulated at the rotation frequency of the scrambler, but this modulation is removed by low pass filtering.

Abstract: In an interferometric sensing apparatus, a scrambler is positioned in front of a polarizer, followed by a detector. In that way, although the two beams remain orthogonal to each other, they are continuously rotated, relative to the polarizer. In some positions, both beams pass through the polarizer and interfere, thus eliminating polarization fading. The signal is amplitude modulated at the rotation frequency of the scrambler, but this modulation is removed by low pass filtering.

Abstract: A marine seismic fiber optic acoustic sensor system having internal mirrors with a low reflectivity written into the fiber to form a series of continuous, linear sensors incorporated in a single fiber, each sensor bounded by a pair of internal mirrors. A pulsed laser provides optical signals to the fiber at a pulse width less than twice the travel time to assure that there will be no phase or frequency modulation of signals returned from the sensors and reflected optical energy is returned through the same fiber to an optical coupler where it is input to a compensating interferometer to produce interference signals which are then time division multiplexed to produce signals corresponding to acoustic signals received by each mirror bound sensor. Calibration to remove local temperature effects is provided by using a desensitized reference fiber with internal mirrors identical to the sensitized fiber, by a piezoelectric stretcher built into the fiber or any other conventional calibration technique.