Fusible Alloy Plug for Passive Wellbore Flow Isolation

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Solution Overview

Problem

Current wellbore flow isolation mechanisms are complex, require mechanical intervention for removal, and lack a simple, passive method to shut off flow without retrieval or complex operations.

Innovation Solution

A flow control device with temporary fusible alloy plugs, made from low melting temperature compositions, is securely installed in apertures to restrict hydraulic flow, which can be passively removed during thermal operations like steam circulation, eliminating the need for mechanical or chemical intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical or hydraulic systems are used for flow isolation, then flow control capability is achieved, but device complexity and need for mechanical intervention increase

Engineering Contradiction:
Improveflow isolation capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical or hydraulic flow isolation systems with a chemically triggered dissolution mechanism. The plug contains a soluble material that dissolves when exposed to formation fluids, eliminating the need for mechanical moving parts, complex actuation systems, or hydraulic pressure mechanisms. This substitution achieves reliable flow isolation during installation while providing automatic, intervention-free removal after the desired period.

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

Solution Approach 2:

The dissolution plug is designed to automatically dissolve and remove itself after a predetermined period or upon contact with specific formation fluids. The soluble material self-decomposes without requiring any external mechanical intervention, retrieval operations, or additional chemical treatments. This self-service mechanism eliminates the need for complex retrieval systems and reduces operational complexity.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If mechanical intervention is used to remove plugs, then plug removal is achieved, but operational complexity and time requirements increase

Engineering Contradiction:
Improveplug removal easeVSAvoidremoval time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent replaces mechanical retrieval operations with a chemical dissolution process. The soluble material in the plug dissolves automatically when exposed to formation fluids or injected chemicals, eliminating the need for mechanical retrieval tools, well interventions, or complex removal operations. This substitution dramatically reduces both the time and operational complexity required for plug removal.

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

Solution Approach 2:

The plug material undergoes a phase transition from solid to dissolved state through chemical dissolution. This phase change allows the plug to transform from a flow-blocking solid structure into soluble components that can be carried away by formation fluids, providing automatic and effortless removal without mechanical intervention.

Inventive Principle:
Principle #36Phase transitions

3Reliability

If permanent plugs are used, then flow isolation is reliable, but adaptability and ease of removal are lost

Engineering Contradiction:
Improveflow isolation reliabilityVSAvoidplug removal flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the chemical composition parameters of the plug material to be soluble rather than permanent. By selecting materials that dissolve under specific conditions (exposure to formation fluids, pH changes, temperature changes, or chemical injection), the plug maintains reliable flow isolation during the desired period while providing automatic adaptability for removal when conditions change. This parameter change enables both reliability and flexibility simultaneously.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The plug transitions from a static, permanent state to a dynamic, time-dependent state. The soluble material allows the plug to automatically change its properties over time or in response to environmental conditions, transforming from a permanent barrier into a temporary, self-removing device. This dynamic behavior provides both reliable initial isolation and automatic adaptability for removal.

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 solution provides a simple, effective method for isolating flow in wellbores, allowing for selective fluid inflow without mechanical or chemical intervention, using heat to remove the fusible alloy plugs, thus reducing operational complexity and enhancing efficiency.

Implementation Method 1

the temporary fusible alloy plugs are fabricated from a low melting temperature composition that is meltable under heated reservoir conditions

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

passively removed during normal steam circulation or injection operations

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP3017141B1Fusible alloy plug in flow control device
Publication Date: 2021.03.03 TOTALENERGIES EP CANADA LTD
  • EP3017141B1 patent drawingFigure 1
  • EP3017141B1 patent drawingFigure 2
  • EP3017141B1 patent drawingFigure 3

AI summary

A "passive" apparatus and method for isolating flow within a thermal wellbore wherein inflow apertures are plugged with a temporary fusible alloy plug that can be selectively removed by increasing the wellbore temperature.