Subsea Latching Assembly Acoustic Control System

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Solution Overview

Problem

Conventional systems for subsea drilling face challenges in unlatching a rotating control device (RCD) or other oilfield devices when the primary electro-hydraulic umbilical line is damaged or impractical to use, especially in deep-sea environments where human divers or ROVs may not be safe or feasible.

Innovation Solution

An acoustic control system is introduced, which includes a surface control unit, a subsea control unit, and acoustic signal devices that can transmit and receive signals to remotely operate a subsea latch assembly, using pressurized hydraulic fluid stored in accumulators to unlatch or latch the RCD, serving as a backup or primary operation method.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If an electro-hydraulic umbilical line is used to operate the subsea latch assembly, then the latching operation can be controlled from the surface, but the system becomes vulnerable to umbilical line damage and requires complex cabling infrastructure

Engineering Contradiction:
Improveremote operation capabilityVSAvoidsystem vulnerability to umbilical damage
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent extracts the hydraulic power supply from the surface umbilical line and places it locally on the subsea latch assembly in the form of accumulators. This eliminates the need for continuous umbilical line connection for power transmission, retaining remote operability while removing the vulnerability associated with long umbilical lines.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces acoustic signaling as an intermediary communication method between the surface and subsea latch assembly. Acoustic signals serve as a reliable mediator that can operate independently of the electro-hydraulic umbilical line, enabling control commands to be transmitted even when the primary umbilical connection is damaged.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If human divers or ROVs are deployed to operate the latching assembly in deep-sea environments, then direct manual intervention is possible, but safety risks and operational feasibility decrease in hazardous conditions

Engineering Contradiction:
Improvedirect manual intervention capabilityVSAvoidsafety risks in deep-sea environments
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The subsea latch assembly is equipped with self-contained accumulators that store hydraulic energy locally. This enables the system to operate autonomously using stored energy, eliminating the need for continuous external power supply or manual intervention by divers or ROVs in hazardous deep-sea environments.

Inventive Principle:
Principle #25Self-service

3Reliability

If a backup acoustic control system is implemented, then operational reliability improves in case of umbilical line damage, but the device complexity increases

Engineering Contradiction:
Improveoperational reliability with backup systemVSAvoidsystem complexity with multiple control methods
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the electro-hydraulic umbilical control system and the acoustic control system into a unified latching assembly. Both control methods share common components such as the hydraulic actuators and latch mechanism, reducing overall system complexity while providing redundant control pathways for improved reliability.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables safe and reliable operation of subsea latching assemblies without the need for a functional electro-hydraulic umbilical line, ensuring continued drilling operations even in hazardous conditions.

Implementation Method 1

an acoustic signal device capable of transmitting an acoustic signal and a subsea control unit with an acoustic signal receiver

Methodology Applied
Scientific EffectAcoustic signal transmission: Sound

Implementation Method 2

a piston movable within the cylinder between a retracted position and an extended position to unlatch or latch the RCD or other oilfield device from the housing

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 3

using pressurized hydraulic fluid stored in accumulators to unlatch or latch the RCD

Methodology Applied
Scientific EffectHydraulic fluid movement: Hydraulic Press

Data Source

PatentEP2630324B1Latching apparatus and method
Publication Date: 2019.09.18 WEATHERFORD TECHNOLOGY HOLDINGS LLC
  • EP2630324B1 patent drawingFigure 1
  • EP2630324B1 patent drawingFigure 1A
  • EP2630324B1 patent drawingFigure 2

AI summary

An acoustic control system wirelessly operates a subsea latching assembly (14, 18) or other subsea device, such as an active seal (22). The acoustic control system may control a subsea first accumulator to release its stored hydraulic fluid to operate the latch assembly or other subsea device, such as an active seal. An RCD or other oilfield device may be unlatched or latched with the latching assembly. The acoustic control system may have a surface control unit, a subsea control unit, and two or more acoustic signal devices. A valve may allow switching from an umbilical line system to the acoustic control system accumulator.