Subsea Fiber Optic Sensor Assembly for Passive Electrical Sensing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Subsea sensor systems face challenges in accurately measuring operating parameters without adding complexity, expense, and potential failure points due to the need for additional electrical infrastructure for conventional sensors.

Innovation Solution

The use of fiber optic sensor assemblies, including fiber Bragg gratings (FBGs), which passively measure parameters using light signals and account for environmental forces like pressure, strain, and temperature, with optional canisters maintaining a controlled pressure to minimize strain effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional sensors are used to measure operating parameters of subsea devices, then measurement capability is provided, but additional electrical infrastructure is required which adds complexity, expense, and potential failure points

Engineering Contradiction:
Improvemeasurement capabilityVSAvoidelectrical infrastructure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces conventional electrical sensors with fiber optic sensors that use light instead of electrical signals. The fiber optic sensing element detects voltage or current through optical means via the electrical connector, eliminating the need for additional electrical infrastructure while maintaining measurement capability. This substitution of optical for electrical systems directly resolves the contradiction by removing complexity without sacrificing measurement precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If fiber optic sensors are used in subsea environment, then measurement accuracy is maintained by being insensitive to environmental pressures, but the sensors are exposed to high pressure, strain, and temperature that can affect measurement

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidenvironmental pressure effects
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary mechanism - the electrical connector - through which the fiber optic sensing element detects electrical parameters. The sensing element is coupled to the electrical connector such that it detects voltage or current via the connector, allowing the sensor to remain protected from direct environmental exposure while still measuring electrical parameters accurately. This intermediary approach maintains measurement accuracy while reducing the harmful effects of the subsea environment.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The fiber optic sensing element uses optical fields instead of electrical fields to detect parameters, making it inherently insensitive to environmental pressures, strain, and temperature that affect conventional electrical sensors. This substitution of optical detection for electrical detection resolves the contradiction by maintaining measurement accuracy while eliminating sensitivity to harmful environmental factors.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If canister with controlled pressure chamber is used to protect fiber optic sensors, then measurement accuracy is maintained by minimizing strain effects, but device complexity and expense increase

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidcanister structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses the electrical connector as an intermediary that allows the fiber optic sensing element to detect electrical parameters without direct exposure to environmental stresses. The sensing element is coupled to the electrical connector such that it detects voltage or current via the connector, which serves as a protected interface. This intermediary approach maintains measurement accuracy while avoiding the need for complex pressure-containing canisters.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Accurate and passive measurement of subsea device parameters is achieved, reducing complexity and potential failure points by using fiber optic sensors that are insensitive to environmental pressures, thus maintaining measurement accuracy.

Implementation Method 1

a fiber optic sensing element positioned in the chamber and coupled to the electrical connector such that the fiber optic sensing element is configured to detect a voltage or a current of the subsea device via the electrical connector

Methodology Applied
Scientific EffectFiber optic sensing: Optical Fibre

Implementation Method 2

a canister that defines a chamber and that is configured to maintain the chamber at a controlled pressure in a subsea environment

Methodology Applied
Scientific EffectPressure control: Pressure Increase

Data Source

PatentEP4707750A1Subsea fiber optic sensor assemblies and related methods
Publication Date: 2026.03.11 ONESUBSEA IP UK LTD
  • EP4707750A1 patent drawingFigure 1
  • EP4707750A1 patent drawingFigure 2
  • EP4707750A1 patent drawingFigure 3

AI summary

An embodiment of a system includes a canister that defines a chamber and that is configured to maintain the chamber at a controlled pressure in a subsea environment. In addition, the system includes an electrical connector defined on the canister that is configured to be electrically coupled to a subsea device. Further, the system includes a fiber optic sensing element positioned in the chamber and coupled to the electrical connector such that the fiber optic sensing element is configured to detect a voltage or a current of the subsea device via the electrical connector.