Subsea Safety Node With Hydraulic Isolation for Extreme Conditions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Underwater hydrocarbon extraction facilities face challenges in protecting components from unforeseen conditions, such as extreme low temperatures, without the need for costly replacements or system alterations.
Innovation Solution
A safety node is retrofitted into the control system, comprising a marinised housing with a functional safety electronics module and a hydraulic manifold, allowing for protection by preventing operation outside design parameters through sensor feedback and hydraulic control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing facilities are protected by replacing entire facilities or components, then reliability is improved, but cost and practicality worsen
Solution Approach 1:
The invention divides the protection system into a separate, modular safety node that can be independently installed on existing facilities without replacing entire components. This segmentation allows the safety function to be added while preserving the original facility structure, thereby improving reliability without incurring the high costs and practical difficulties of full replacement.
Solution Approach 2:
The safety node acts as an intermediary device between the existing facility components and the control system. It monitors operating conditions and intervenes only when necessary to prevent operation outside design parameters, thus providing protection without requiring replacement of the original facility components.
2Ease of manufacture
If existing facilities are protected by retrofitting with a safety node, then cost and practicality are improved, but device complexity increases
Solution Approach 1:
The safety monitoring and control functions are extracted from the main control system and placed into a dedicated safety node. This extraction simplifies the integration process during retrofitting, as the safety node operates semi-independently with its own sensor interfaces and hydraulic control, thereby reducing the complexity burden on the existing control system.
Solution Approach 2:
The safety node is designed to be self-contained with integrated sensor connections, power supply, logic processing, and hydraulic actuation capabilities. This self-service design minimizes the need for additional system modifications during retrofitting, reducing installation complexity while maintaining cost-effectiveness.
3Reliability
If safety node commands DCV to switch paths, then protection from extreme conditions is achieved, but loss of hydraulic fluid occurs
Solution Approach 1:
The vent line, which initially appears to represent a loss of hydraulic fluid, is designed to safely discharge to the sea environment. The controlled venting of small amounts of fluid provides a reliable fail-safe mechanism that protects the facility from extreme conditions, converting the potential harm of fluid loss into a beneficial safety feature that prevents catastrophic failure.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A safety node 1 for a hydrocarbon extraction facility control system, the node comprising: a hydraulic input 11; a hydraulic output 12; a directional control valve 10 disposed between the hydraulic input and the hydraulic output; and a functional safety electronics module 4 containing a logic solver 6 in operable communication with the directional control valve; wherein the logic solver is configured to operate the directional control valve to permit hydraulic communication between the hydraulic input and the hydraulic output in response to the presence of a given condition and inhibit hydraulic communication between the hydraulic input and the hydraulic output in response to the absence of a given condition.