Explosive Frangible Nuts for Rapid LMRP-BOP Disconnect

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Solution Overview

Problem

Existing methods for disconnecting a lower marine riser package (LMRP) from a well pressure control device are time-consuming, often taking over a minute, and are limited by permissible connector release angles during adverse weather conditions, necessitating early disconnection decisions and restricting platform movement.

Innovation Solution

The use of explosively frangible nuts with electronic triggering, housed within a sealed environment, to rapidly disconnect the LMRP from a BOP stack, allowing for a larger angle of separation and enabling quick reconnection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If traditional uncoupling methods (unthreading threaded connectors, removing coupling bolts) are used to disconnect LMRP from BOP stack, then the connection can be disconnected, but the disconnect time exceeds one minute and platform movement is restricted by small permissible release angles

Engineering Contradiction:
Improvedisconnect timeVSAvoidplatform movement flexibility
Core Design Contradiction:
Loss of timeVSAdaptability or versatility

Solution Approach 1:

The patent replaces traditional mechanical uncoupling methods (unthreading connectors, removing bolts) with an explosive system. Explosively frangible fasteners and profile connectors with explosive charges enable instantaneous separation through chemical energy conversion, reducing disconnect time from over one minute to near-instantaneous separation while allowing greater platform movement angles.

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

Solution Approach 2:

The patent changes the physical state and properties of the connection system by introducing explosively frangible fasteners that transition from a solid mechanical connection to fragmented separation through controlled explosion. This parameter change enables rapid disconnection and increases the permissible release angle for platform movement during disconnect operations.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If explosive frangible fasteners are used to couple connector between LMRP and BOP, then disconnect time is reduced, but the complexity of the device increases

Engineering Contradiction:
Improvedisconnect speedVSAvoidconnector system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into integrated explosive connector assemblies that combine mechanical coupling, explosive charging, and frangible separation capabilities in unified components. The profile connectors and frangible fasteners are designed as integrated systems where the explosive mechanism is embedded within the mechanical connection structure, reducing overall system complexity despite the advanced functionality.

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

Facilitates rapid and reliable disconnection of the LMRP from the BOP stack, reducing disconnect time and enhancing operational flexibility under adverse conditions while maintaining structural integrity.

Implementation Method 1

at least one explosive charge disposed on each of the frangible nuts

Methodology Applied
Scientific EffectExplosion: Explosion

Implementation Method 2

electronic triggering to detonate the explosive charges

Methodology Applied
Scientific EffectDetonation: Detonation

Data Source

PatentEP3981946B1Explosive disconnect
Publication Date: 2025.12.17 KINETIC PRESSURE CONTROL LTD
  • EP3981946B1 patent drawingFigure 1
  • EP3981946B1 patent drawingFigure 2
  • EP3981946B1 patent drawingFigure 2

AI summary

A coupling system, comprising: a lower marine riser package (12) configured with a connector (10B); a blowout preventer (14) configured with a connector (10A); explosively frangible fasteners comprising explosively frangible nuts (10C) disposed to couple the lower marine riser package connector (10B) to the blowout preventer connector (10A), wherein the explosively frangible nuts are sealed off from the external environment; each explosively frangible nut having at least one explosive charge (34) disposed thereon; and at least one explosively frangible nut configured for electronic triggering to set off the at least one explosive charge disposed on the nut.