Abstract: A system and method for controlling hydrogen concentration in optical sensing systems in subsurface wells. In an exemplary system the downhole optical fiber sensors are positioned within nested conduits and a controlled concentration hydrogen gas is flowed in a first direction through the first conduit, and flowed in a second direction through the annulus, wherein the second direction is opposite to the first direction.

Abstract: A method of improving sampling resolution in a distributed temperature measurement system using a fiber optic distributed sensor by means of programmed delayed trigger signals to a laser light source in order to improve the spatial resolution of such systems.

Abstract: A system and method for providing greatly improved linear heat detection using fiber optic distributed temperature systems (DTS). The invention makes use of correction algorithms based on proportional-integral-derivative notions that anticipate exterior temperature increases based on the rate of measured temperature changes.

Abstract: A system for sensing downhole pressure in in a hydrocarbon well using a Fabry-Perot (F-P) sensor in series with a Fiber Bragg Grating and maintaining the back pressure on the sensor system with a surface sealing system and a surface pressure control system.

Abstract: A downhole optical sensing system can include an optical fiber positioned in the well, the optical fiber including multiple cores, and at least one well parameter being sensed in response to light being transmitted via at least one of the multiple cores in the well. The multiple cores can include a single mode core surrounded by a multiple mode core. A method of sensing at least one well parameter in a subterranean well can include transmitting light via at least one of multiple cores of an optical fiber in the well, the at least one of the multiple cores being optically coupled to a sensor in the well, and/or the at least one of the multiple cores comprising a sensor in the well, and determining the at least one well parameter based on the transmitted light.

Abstract: A downhole optical sensing system can include an optical fiber positioned in the well, the optical fiber including multiple cores, and one of the cores having a Brillouin scattering coefficient which is different from another one of the cores. A method of sensing strain and temperature as distributed along an optical fiber can include measuring Brillouin scattering in a core of the optical fiber disposed in a well, and measuring Brillouin scattering in another core of the optical fiber disposed in the well, the optical fiber cores being exposed to a same strain and temperature distribution in the well.

Abstract: A downhole optical system can include an optical fiber disposed in a subterranean well, and an optical fiber amplifier which amplifies optical power in a core of the optical fiber in the well, the amplifier being optically pumped with optical power in another core of the optical fiber in the well. Another downhole optical system can include an optical fiber disposed in a subterranean well, the optical fiber comprising multiple cores, and an optical fiber amplifier comprising multiple cores optically coupled respectively to the optical fiber multiple cores in the well.

Abstract: A system and method for monitoring oil flow rates at multiple points in production wells using a flow sensing fiber optic cable. An illustrative system embodiment includes: a fiber optic sensing system housed within a tube suitable for a downhole environment; and a flow to signal conversion device attached to the tube and deployed in the oil flow.

Abstract: A coiled tubing servicing system comprising a servicing cart comprising two or more support frames, a length of coiled tubing supported by the servicing cart, a servicing fixture disposed about a portion of the length of coiled tubing adjacent the servicing cart, wherein the servicing fixture is movable along a longitudinal axis of the length of coiled tubing and radially about the longitudinal axis of the length of coiled tubing; and a servicing tool coupled to the servicing fixture.

Abstract: A method for installing multiple fiber optic cables in coiled tubing in oil and gas operations.

Abstract: A method for installing multiple fiber optic cables in coiled tubing in oil and gas operations.

Abstract: A multiple integral pressure transducer system for installation in oil field downhole coiled tubing systems.

Abstract: A method and device for relieving thermal stresses on the optical fibers in fiber optic splice housings used in hostile thermal environments.

Abstract: A method for re-calibrating installed downhole sensors used in hydrocarbon wells by the application of a calibration string inserted in the wells and deployed in close proximity to the installed downhole sensor.

Abstract: A system and method using both static and transient modeling of power cables coupled with real time measurements of distributed temperature profiles of both the cable and it's immediate environment to optimize the current loads of the power cable. The optical fibers used for measuring distributed temperature profiles can be integrated directly into the monitored power cables or be deployed alongside the power cables, including using the optical fibers deployed in optical power ground wire systems.

Abstract: A method of measuring an electromagnetic field in a formation can include installing an electromagnetic sensor with improved sensitivity, the sensor including multiple optical waveguides and respective multiple materials, and in response to exposure to the electromagnetic field, the materials changing shape in opposite directions. A well system can include an optical electromagnetic sensor which measures an electromagnetic field in a formation, and wherein optical path lengths or phases in optical waveguides of the sensor change both positively and negatively in response to exposure to the electromagnetic field.

Abstract: A tubular seismic sensing cable for use in wells and a method of deployment into wells to provide higher seismic sensitivity.

Abstract: An apparatus and method for use in distributed temperature sensing (DTS) systems to reduce coherent Rayleigh scattering in fiber optic cables by using photonic crystal fibers.

Abstract: High resolution distributed temperature sensors using fiber optic distributed temperature sensing systems deployed on various carriers to significantly improve spatial resolution and provide high resolution temperature profile and detection of fluid or fluid interface levels.

Abstract: A system for monitoring subsidence and/or rising of a waterbottom has string of pressure sensors along the interior of a sealed -protective tube(q?) that rests on the waterbottom and is filled with a low pressure liquid, so that any subsidence and/or rising of the can be deduced from subsidence and/or rising of a section of the tube and associated pressure variations measured by the sensors due to variation of the hydrostatic fluid pressure of the liquid in the of the tube. The tube interior is divided into segments by valves during descent to protect the sensors against hydrostatic pressure of the liquid within the tube during installation. The use of a low pressure liquid in the tube allows the use of sensitive pressure sensors which are able to monitor pressure variations of ?0.001 Bar associated with a waterbottom subsidence of ?1 cm, at a water depth of >km where the ambient water pressure may be >100 Bar.