Abstract: Certain aspects of the present disclosure provide techniques for making armored cables. An example method for making an armored cable includes forming a strip stock into an armor tubing; welding a seam of the armor tubing in a welding zone; inserting at least one of a first optical fiber or a first wire into a first end of a first guide tube, wherein: the first guide tube extends through the welding zone; the first guide tube protects the at least one of the first optical fiber or the first wire during the welding of the seam; and the first guide tube is not part of the armored cable after the making of the armored cable; and supporting the first guide tube within the armor tubing by a plurality of support legs such that the first guide tube does not contact the armor tubing.

Abstract: Certain aspects of the present disclosure provide techniques for making armored cables. An example method for making an armored cable includes forming a strip stock into an armor tubing; welding a seam of the armor tubing in a welding zone; inserting at least one of a first optical fiber or a first wire into a first end of a first guide tube, wherein: the first guide tube extends through the welding zone; the first guide tube protects the at least one of the first optical fiber or the first wire during the welding of the seam; and the first guide tube is not part of the armored cable after the making of the armored cable; and supporting the first guide tube within the armor tubing by a plurality of support legs such that the first guide tube does not contact the armor tubing.

Abstract: Certain aspects of the present disclosure provide techniques for making armored cables. An example method for making an armored cable includes forming a strip stock into an armor tubing; welding a seam of the armor tubing in a welding zone; inserting at least one of a first optical fiber or a first wire into a first end of a first guide tube, wherein: the first guide tube extends through the welding zone; the first guide tube protects the at least one of the first optical fiber or the first wire during the welding of the seam; and the first guide tube is not part of the armored cable after the making of the armored cable; and supporting the first guide tube within the armor tubing by a plurality of support legs such that the first guide tube does not contact the armor tubing.

Abstract: Certain aspects of the present disclosure provide techniques for making armored cables. An example method for making an armored cable includes forming a strip stock into an armor tubing; welding a seam of the armor tubing in a welding zone; inserting at least one of a first optical fiber or a first wire into a first end of a first guide tube, wherein: the first guide tube extends through the welding zone; the first guide tube protects the at least one of the first optical fiber or the first wire during the welding of the seam; and the first guide tube is not part of the armored cable after the making of the armored cable; and supporting the first guide tube within the armor tubing by a plurality of support legs such that the first guide tube does not contact the armor tubing.

Abstract: Certain aspects of the present disclosure provide techniques for making armored cables. An example method for making an armored cable includes forming a strip stock into an armor tubing; welding a seam of the armor tubing in a welding zone; inserting at least one of a first optical fiber or a first wire into a first end of a first guide tube, wherein: the first guide tube extends through the welding zone; the first guide tube protects the at least one of the first optical fiber or the first wire during the welding of the seam; and the first guide tube is not part of the armored cable after the making of the armored cable; and supporting the first guide tube within the armor tubing by a plurality of support legs such that the first guide tube does not contact the armor tubing.

Abstract: Certain aspects of the present disclosure provide techniques and corresponding apparatus for making armored cables with one or more optical fibers contained therein. The techniques may be utilized to control an amount of excess fiber length (EFL) in the armored cables. The techniques may also allow introduction of one or more optical fibers directly into a welding process without using an inner tube in the final armored cable. The techniques may also be utilized to reduce friction and static charge on the optical fiber(s) as the fiber(s) are pushed through one or more guide tubes that protect the fiber(s) during the welding process.

Abstract: Methods and apparatus for performing Distributed Acoustic Sensing (DAS) using fiber optics with increased acoustic sensitivity are provided. Acoustic sensing of a wellbore, pipeline, or other conduit/tube based on DAS may have increased acoustic sensitivity through fiber optic cable design and/or increasing the Rayleigh backscatter property of a fiber's optical core. Some embodiments may utilize a resonant sensor mechanism with a high Q coupled to the DAS device for increased acoustic sensitivity.

Abstract: Embodiments of the present invention provide methods and apparatus for cables having one or more fibers that may function as a sensing device within a wellbore, wherein the fibers do not adhere to each other or to an inner wall of the cable during a high temperature operation, such as in a thermal recovery operation that may last over 30 days.

Abstract: Purging interior regions of a cable reduces or prevents hydrogen darkening of an optical fiber located in the cable. While hydrogen may permeate through an outer surface of the cable, fluid circulating through the cable purges the hydrogen from within the cable. This circulation of the fluid occurs between an inner tube containing the fiber and an outer tube surrounding the inner tube.

Abstract: Methods and apparatus for performing Distributed Acoustic Sensing (DAS) using fiber optics with increased acoustic sensitivity are provided. Acoustic sensing of a wellbore, pipeline, or other conduit/tube based on DAS may have increased acoustic sensitivity through fiber optic cable design and/or increasing the Rayleigh backscatter property of a fiber's optical core. Some embodiments may utilize a resonant sensor mechanism with a high Q coupled to the DAS device for increased acoustic sensitivity.

Abstract: Certain aspects of the present disclosure provide techniques and corresponding apparatus for making armored cables with one or more optical fibers contained therein. The techniques may be utilized to control an amount of excess fiber length (EFL) in the armored cables. The techniques may also allow introduction of one or more optical fibers directly into a welding process without using an inner tube in the final armored cable. The techniques may also be utilized to reduce friction and static charge on the optical fiber(s) as the fiber(s) are pushed through one or more guide tubes that protect the fiber(s) during the welding process.

Abstract: Methods and apparatus for performing Distributed Acoustic Sensing (DAS) using fiber optics with increased acoustic sensitivity are provided. Acoustic sensing of a wellbore, pipeline, or other conduit/tube based on DAS may have increased acoustic sensitivity through fiber optic cable design and/or increasing the Rayleigh backscatter property of a fiber's optical core. Some embodiments may utilize a resonant sensor mechanism with a high Q coupled to the DAS device for increased acoustic sensitivity.

Abstract: Embodiments of the present invention provide methods and apparatus for cables having one or more fibers that may function as a sensing device within a wellbore, wherein the fibers do not adhere to each other or to an inner wall of the cable during a high temperature operation, such as in a thermal recovery operation that may last over 30 days.

Abstract: Embodiments of the present invention provide methods and apparatus for cables having one or more fibers that may function as a sensing device within a wellbore, wherein the fibers do not adhere to each other or to an inner wall of the cable during a high temperature operation, such as in a thermal recovery operation that may last over 30 days.

Abstract: Large diameter optical waveguides (cane) may stiffen as diameter increases. The minimum bend radius may become larger than is practical for many applications. Standard-sized optical fibers may be fusion spliced to the ends of a cane segment where the fusion splice area is protected with a high temperature coating such as polyimide. The cane segment is then heated (e.g., using a hot flame torch or arc) and bent to form a U-bend, or other angle, that is free of bending stress. The heated glass may be shaped, while maintaining the waveguide properties of the cane. Once cooled, the cane maintains the new shape. Therefore, light may be propagated around the bend or angle. Thus, many configurations of cane devices may be fabricated. Some examples of cane configurations include coils, U-turns (U-bends), angled inputs/outputs, etc. Bent cane may be useful for loop-back operations, such as double-ended Raman distributed temperate sensing (DTS).

Abstract: The present invention provides a method for making a multicore large diameter optical waveguide having a cross-section of at least about 0.3 millimeters, two or more inner cores, a cladding surrounding the two or more inner cores, and one or more side holes for reducing the bulk modulus of compressibility and maintaining the anti-buckling strength of the large diameter optical waveguide. The method features the steps of: assembling a preform for drawing a multicore large diameter optical waveguide having a cross-section of at least about 0.3 millimeters, by providing an outer tube having a cross-section of at least about 0.3 millimeters and arranging two or more preform elements in relation to the outer tube; heating the preform; and drawing the large diameter optical waveguide from the heated preform. In one embodiment, the method also includes the step of arranging at least one inner tube inside the outer tube.

Abstract: Methods and apparatus relate to optical fibers suitable for use in sensing applications exposed to radiation environments. The fibers include a core of pure silica or chlorine doped silica surrounded by a fluorinated silica cladding. These glasses for the core and cladding utilize dopants that resist radiation-induced attenuation. A two step process for forming the cladding can achieve necessary concentrations of the fluorine by performing a soot deposition process in a different environment from a consolidation process where the soot is sintered into a glass. Concentration of fluorine doped into the cladding layer enables obtaining a numerical aperture that confines a mono-mode of the fiber to resist bend-induced attenuation. Dimensions of the fiber further facilitate bending ability of the fiber.

Abstract: Methods to fabricate an optical preform for draw into Polarization Maintaining (PM) or Polarizing (PZ) optical fiber are provided. The methods involve assembly of pre-shaped and pieced together bulk glass elements into preforms (“assembled preforms”) for simultaneous fusing and drawing into optical fiber. These preforms form a stress-induced birefringent optical core when drawn to fiber.

Abstract: Methods to fabricate an optical preform for draw into Polarization Maintaining (PM) or Polarizing (PZ) optical fiber are provided. The methods involve assembly of pre-shaped and pieced together bulk glass elements into preforms (“assembled preforms”) for simultaneous fusing and drawing into optical fiber. These preforms form a stress-induced birefringent optical core when drawn to fiber.

Abstract: Method and apparatus enable optical evanescent sensing utilizing a waveguide with an annular core. The annular core can provide detectable sensitivity to a measurand due to optical interactions with contents along an inside surface of the annular core since optical properties of the contents vary with changes in the measurand.