Embodiments of the present invention provide a unique new approach to generating operating condition information used for assessing flow assurance and structural integrity. More specifically, apparatuses, systems and sensor housing assemblies configured in accordance with embodiments of the present invention utilize fiber optic sensors for enabling monitoring of operating condition information within one or more elongated tubular members within a subsea environment. To this end, such fiber optic sensors connected by lengths of optical fiber are strategically placed at a plurality of locations along a length of each elongated tubular member thereby allowing critical operating conditions such as strain, temperature and pressure of the elongated tubular member and/or a fluid therein to be monitored. A viscous media is used for mitigating attenuation associated with exposure of optical fiber exposed to forces generated by pressure within the subsea environment.

According to an example aspect of the present invention, there is provided a sensor comprising at least one strut configured to be coupled to a surface of an object at a first end of the strut, a structure connected to a second end of the at least one strut, wherein the structure is V-shaped, U-shaped, curved or arched and configured to be coupled to the surface at both ends, a plurality of cavities positioned along the structure on both sides of the at least one strut, and a plurality of fibre-optic pressure transducers, wherein a single fibre-optic pressure transducer is arranged within each of the cavities, and wherein the sensor is configured such that at least some of the fibre-optic pressure transducers are arranged at different distances from the surface of the object.

A device for testing overall anchorage performance of a basalt fiber reinforced plastic (BFRP) anchor cable includes an anchor cable anchoring system and a data acquisition system. The anchor cable anchoring system includes a test bed, BFRP arranged over the test bed, and a distributed optical fiber bonded to a surface of the BFRP, the test bed being provided with an anchoring section at one end and an outer anchoring section at the other end, the anchoring section anchors one end of the BFRP, and the outer anchoring section anchors the other end of the BFRP. The data acquisition system includes a modem and a grating connected to two ends of the distributed optical fiber in series, and a center hole jack and a dynamometer arranged between the outer anchoring section and an end of the test bed, and the BFRP penetrates the center hole jack and the dynamometer.

A fiber optic sensor and a related method of manufacture are provided. The fiber optic sensor includes an embedded optical fiber contained within a metal diaphragm assembly, where the terminal end of the optical fiber is positioned opposite a diaphragm. The method includes forming a metal-embedded optical fiber by ultrasonic additive manufacturing and securing the metal-embedded optical fiber to a housing having a diaphragm that is opposite of the terminal end of the optical fiber. The sensor can provide extremely accurate pressure measurement at high temperatures and in highly corrosive media. An optical fiber-based pressure sensing system is also provided.

Embodiments of the present invention provide a unique new approach to generating operating condition information used for assessing flow assurance and structural integrity. More specifically, apparatuses, systems and sensor housing assemblies configured in accordance with embodiments of the present invention utilize fiber optic sensors for enabling monitoring of operating condition information within one or more elongated tubular members within a subsea environment. To this end, such fiber optic sensors connected by lengths of optical fiber are strategically placed at a plurality of locations along a length of each elongated tubular member thereby allowing critical operating conditions such as strain, temperature and pressure of the elongated tubular member and/or a fluid therein to be monitored. A viscous media is used for mitigating attenuation associated with exposure of optical fiber exposed to forces generated by pressure within the subsea environment.

A sensor (10) comprises a waveguide (20) having a longitudinal axis and an end face (21), the waveguide (20) comprising a Bragg grating (23). The sensor comprises at least one reflector (24) on the end face (21) of the waveguide (20). An optical resonator (25) is formed by the Bragg grating (23), the at least one reflector (24), and an inner portion of the optical resonator (25) between the Bragg grating (23) and the at least one reflector (24). The inner portion of the optical resonator (25) extends within a portion of the waveguide (20). The sensor (10) comprises a detector (32) configured to detect at least one spectral characteristic of the optical resonator (25) or a change of at least one spectral characteristic of the optical resonator (25).

An optical fiber cable (10) according to each of the present disclosures includes a long tube (11) and at least one optical fiber (12) held and passed through an inside of the tube (11). The tube (11) expands and contracts in a longitudinal direction when water pressure on an outside of the tube (11) changes. When the tube (11) expands and contracts in the longitudinal direction, the expansion and contraction of the tube (11) in the longitudinal direction is transmitted to the optical fiber (12) to expand and contract the optical fiber (12) in the longitudinal direction.

A machine learning system and method are provided for using fiber-optic Distributed Acoustic Sensor (DAS) and Distributed Temperature Sensor (DTS) data to predict pressure along one or more optical fiber cables. DAS and DTS data are used to train a model to predict pressure based on the DAS and DTS data corresponding to optical signals carried on the fiber cable(s). The trained model is then used to process acquired DAS and DTS data corresponding to optical signals carried on the fiber cable(s) to the predict pressure distributed along the cable(s).

A load sensing system for sensing a load on a structure can include an optical load sensing element configured to change an optical state based on a force applied thereto, an optical source operatively connected to the optical load sensing element and configured to input an input optical signal to the optical load element, and an optical detector configured to receive a returned optical signal from the optical load sensing element. The optical detector can be configured to detect one or more frequency peaks of the returned optical signal and to use the one or more frequency peaks of the returned optical signal to correlate to a load value of the load and output the load value indicative of the load.

A long-term in-situ observation device for the deep sea bottom supported engineering geological environment is provided, including: a sediment acoustic probe, a sediment pore water pressure probe, a three-dimensional resistivity probe, a water observation instrument, a long-term observation power supply system, a probe hydraulic penetration system, a general control and data storage transmission system, an acoustic releaser, an underwater acoustic communication apparatus, and an instrument platform. The observations include the engineering properties, physical properties, mechanical properties, and biochemical properties of a seawater-seabed interface-sediment. The engineering properties and the physical and mechanical indexes of seafloor sediments are comprehensively determined by three-dimensional measurement of seafloor resistivity and acoustic wave measurements. The physical and biochemical properties of seawater are expected to be acquired by sensors. The observation probe penetrates into the sediments following the hydraulic method.