A fiber optic sensing (FOS) system and method. The system may include one or more interrogator units and a proximal wavelength division multiplexer (WDM) and a distal WDM optically connectable to the one or more interrogator units, an upgoing transmission fiber, a down-going transmission fiber, and one or more downhole sensing fibers. The method may include transmitting one or more light pulses from an interrogator unit, multiplexing the one or more light pulses from the interrogator unit with a proximal WDM into an upgoing transmission fiber and a down-going transmission fiber, and receiving the one or more light pulses with a distal WDM. The method may further include multiplexing the one or more light pulses from the upgoing transmission fiber and the down-going transmission fiber into one or more downhole sensing fibers and receiving backscatter light from at least one of the one or more downhole sensing fibers.

A subsea multiphase fluid separation system has a gas separator for separating gas from a well stream containing oil. A water separation stage downstream of the gas separator has at least one dual pipe separator for separating water from the oil of the wellstream. A water treatment system for cleaning oil from water is produced by the water separation stage. On an oil outlet path, downstream of the or each dual pipe separator, there is an electrocoalescer and at least one second separator in series.

A subsea multiphase fluid separation system has a gas separator for separating gas from a well stream containing oil. A water separation stage downstream of the gas separator has at least one dual pipe separator for separating water from the oil of the wellstream. A water treatment system for cleaning oil from water is produced by the water separation stage. On an oil outlet path, downstream of the or each dual pipe separator, there is an electrocoalescer and at least one second separator in series.

A subsea sensor hub is for a coupling sensor element to an electrical unit. In an embodiment, he subsea sensor hub includes a first end for receiving a sensor element, a second end for receiving the electrical unit, and at least one through hole extending from the first end to the second end. Furthermore, at least one electrical connecting element is arrangeable to extend through the at least one through hole.

An initiator monitoring and actuating system includes a first power supply selectively electrically connectable to a charge initiator. The first power supply provides a current lower than an activation current of the initiator. A second power supply is selectively electrically connectable to the charge initiator. The second power supply provides a current of at least the activation current. Switches are selectively operable to connect the second power supply to a test circuit operable to measure a current generated by the second power supply. The switches are selectively operable to connect the second power supply to the charge initiator. A current sensor is operable to measure current through the test circuit and operable to measure current from the first power supply when the first power supply is connected to the charge initiator.

An initiator monitoring and actuating system includes a first power supply selectively electrically connectable to a charge initiator. The first power supply provides a current lower than an activation current of the initiator. A second power supply is selectively electrically connectable to the charge initiator. The second power supply provides a current of at least the activation current. Switches are selectively operable to connect the second power supply to a test circuit operable to measure a current generated by the second power supply. The switches are selectively operable to connect the second power supply to the charge initiator. A current sensor is operable to measure current through the test circuit and operable to measure current from the first power supply when the first power supply is connected to the charge initiator.

A subsea sensor module includes a sensor housing having a first section, a second section and a third section, each section having an outer profile and a module flange having an inner profile. An outer surface of the flange is substantially perpendicular to an outer surface of the housing in the first section. The housing outer profile and flange inner profile are substantially the same along the second section of the housing. A shoulder is formed in the housing outer profile in the third section by a transition of the diameter of the outer profile from a smaller to a larger diameter. The flange has a corresponding shoulder in the flange inner profile; wherein the flange is shrink fit mounted radially outwardly of the sensor housing second section such that the shoulders are in contact.

A subsea sensor module includes a sensor housing having a first section, a second section and a third section, each section having an outer profile and a module flange having an inner profile. An outer surface of the flange is substantially perpendicular to an outer surface of the housing in the first section. The housing outer profile and flange inner profile are substantially the same along the second section of the housing. A shoulder is formed in the housing outer profile in the third section by a transition of the diameter of the outer profile from a smaller to a larger diameter. The flange has a corresponding shoulder in the flange inner profile; wherein the flange is shrink fit mounted radially outwardly of the sensor housing second section such that the shoulders are in contact.

Systems, devices and methods enable generation and monitoring of support platform structural conditions in a manner that overcomes drawbacks associated with conventional approaches (e.g., load cells) for generating and monitoring similar operating condition information. In preferred embodiments, such systems, devices and methods utilize fiber optic strain gauges (i.e., fiber optic sensors) in place of (e.g., retrofit/data replacement) or in combination with conventional load cells. The fiber optic sensors are strategically placed at a plurality of locations on one or more support bodies of a support platform. In preferred embodiments, the fiber optic strain gauges are placed in positions within a hull and/or one or more pontoons of an offshore platform. Such positions are selected whereby resulting operating condition data generated by the fiber optic strain gauges suitably replaces data received by conventionally constructed and located load cells of an offshore platform (e.g., a TLP).

Systems and methods for initiating an emergency disconnect sequence (EDS) are provided. In an aspect, a disconnection system is provided and configured to initiate the EDS, and includes a controller including a processor and a memory operably coupled to the processor. The controller receives, from a set of motion reference units (MRU(s)) operably coupled to a flexible joint, position data generated by the set of motion references units and associated with the joint when the joint is operably coupled to and disposed between a drilling riser and a lower marine riser package (LMRP). The controller determines, based on the position data, an angular offset of the joint. The controller sends, to a subsea control pod disposed at or adjacent to the LMRP, a trigger signal in response to determining that the angular offset exceeds a predetermined threshold, such that the subsea control pod initiates the EDS.