Abstract: Strain sensor, including an elongated protective encasing (5) surrounding an inner space, and an optical fiber (3) extending through the encasing (5), the fiber (3) at least including a fiber core (3a) and a fiber cladding (3b), wherein a cured filler material fills (4) at least part of a space between the fiber (3) and the protective encasing (5), the cured filler material (4) being configured for allowing strain coupling between the protective encasing (5) and the fiber (3), wherein an outer diameter of the fiber (3) is at least about 250 ?m, and wherein the cured filler material (4) is one or more of: a flexible material, a resilient material, and a material having a shore A hardness that is lower than about 50. The invention also provides a method and system for manufacturing a strain sensor.

Abstract: The invention relates to a cable suitable for supplying power to a drilling rig's top-drive assembly. In a typical embodiment, the power cable includes (i) a plurality of high-conductivity conductors, (ii) an electromagnetic shield, (iii) two protective sheaths, and (iv) a reinforcing layer of braided aramid fibers between the protective sheaths.

Abstract: Strain sensor, including an elongated protective encasing (5) surrounding an inner space, and an optical fiber (3) extending through the encasing (5), the fiber (3) at least including a fiber core (3a) and a fiber cladding (3b), wherein a cured filler material fills (4) at least part of a space between the fiber (3) and the protective encasing (5), the cured filler material (4) being configured for allowing strain coupling between the protective encasing (5) and the fiber (3), wherein an outer diameter of the fiber (3) is at least about 250 ?m, and wherein the cured filler material (4) is one or more of: a flexible material, a resilient material, and a material having a shore A hardness that is lower than about 50. The invention also provides a method and system for manufacturing a strain sensor.