Mechanical Barrier Fluid Pressure Regulation for Subsea Rotating Machines

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional subsea pump and compressor systems rely on topside control systems for maintaining a pressure differential between barrier fluid and process fluid, which are vulnerable to transient conditions and power blackouts, limiting their reliability and requiring complex electrical systems.

Innovation Solution

A mechanical pressure regulation system with a mechanically actuated valve mechanism that maintains a desired pressure differential between barrier fluid and process fluid, using a pilot piston to automatically supply or dump barrier fluid based on pressure thresholds, independent of electrical power or signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a topside control system with electrically actuated valves is used to maintain barrier fluid pressure differential, then the system can provide controlled pressure regulation, but the system becomes vulnerable to transient conditions and power blackouts, reducing reliability

Engineering Contradiction:

Improvesystem reliabilityVSAvoidcontrol system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the electrical control system with a purely mechanical pressure regulation system. The mechanical valve mechanism uses pressure differential forces acting on a piston to automatically control barrier fluid flow, eliminating the need for electrical power, sensors, and control electronics while improving reliability in transient conditions

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The mechanical valve mechanism is self-regulating, using the pressure differential between barrier fluid and process fluid to automatically open or close the valve without external control signals. The system serves itself by using the process fluid pressure to actuate the valve when differential pressure exceeds thresholds

Inventive Principle:

Principle #25Self-service

2Measurement precision

If electrically actuated and piloted valves are used for barrier fluid pressure control, then precise pressure differential maintenance is achieved, but the system requires electrical power and becomes limited in power blackout situations

Engineering Contradiction:

Improvepressure differential control precisionVSAvoidelectrical power consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent uses hydraulic principles where pressure differential forces from the barrier fluid and process fluid directly act on a piston to mechanically open or close the valve. This eliminates electrical power requirements while maintaining precise pressure differential control through fluid pressure forces

Inventive Principle:

Principle #29Pneumatics and hydraulics

Solution Approach 2:

The electrical actuation system is replaced with a mechanical actuation system where pressure forces directly move the valve mechanism. The piston responds mechanically to pressure differential changes without requiring electrical signals or power

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If barrier fluid is rapidly filled or dumped to maintain pressure differential under dynamic conditions, then the pressure threshold is maintained, but conventional topside control systems respond slowly to fast transient conditions

Engineering Contradiction:

Improvepressure regulation response speedVSAvoidresponse to transient conditions

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The mechanical valve mechanism is inherently dynamic, responding immediately to changes in pressure differential without electrical signal delays. The piston and valve mechanism move rapidly in response to fast transient conditions, enabling quick barrier fluid filling or dumping to maintain pressure thresholds

Inventive Principle:

Principle #15Dynamics

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

The mechanical pressure regulation system ensures reliable and efficient control of barrier fluid pressure, reducing system complexity and costs, enabling robust and fast-acting operation even in power blackout situations, and allowing for the use of all-electric process valve actuation and subsea placement of barrier fluid reservoirs.

Implementation Method 1

the mechanical valve mechanism is mechanically actuated via pressures applied to a pilot piston so as to provide barrier fluid to the rotating machine when the pressure differential reaches a lower limit and to dump barrier fluid when the pressure differential reaches an upper limit

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentUS11378083B2Mechanical barrier fluid pressure regulation for subsea systems

Publication Date: 2022.07.05 ONESUBSEA IP UK LTD

AI summary

A technique facilitates controlling barrier fluid via a mechanical pressure regulation system which may be coupled with a rotating machine at a subsea location. The mechanical pressure regulation system enables controlled supply of the barrier fluid to the rotating machine and comprises a mechanical valve mechanism. The mechanical valve mechanism automatically maintains a pressure differential between the barrier fluid and a process fluid within a desired range. According to an embodiment, the mechanical valve mechanism is mechanically actuated via pressures applied to a pilot piston so as to provide barrier fluid to the rotating machine when the pressure differential reaches a lower limit and to dump barrier fluid when the pressure differential reaches an upper limit.