Exothermic Alloy Well Plugging for Mud-Contaminated P&A Seals

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Solution Overview

Problem

Current plug and abandonment (P&A) operations face challenges such as contamination from drilling fluid channels and regulatory requirements for effective sealing across hydrocarbon-bearing formations, which are not adequately addressed by conventional cementing methods.

Innovation Solution

A method involving a downhole tool to remove casing sections, deploy a blocking device, and use an exothermic fluid to liquefy and solidify a low-melt alloy or metal plugging material for a cast-in-place plug, which expands to create a secure seal without mixing with drilling fluids.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional cementing methods are used, then plugging operations can be performed, but contamination from drilling fluid channels occurs and extensive mud removal is required

Engineering Contradiction:
Improvesealing effectivenessVSAvoiddrilling fluid contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the physical state parameter of the plugging material by using low-melt alloy that transitions from solid to liquid when exposed to exothermic fluid, then back to solid. This phase change allows the material to flow and fill annular spaces effectively without being affected by drilling fluid contamination, resolving the contradiction between sealing effectiveness and contamination issues

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the conventional mechanical cementing system with a thermal-based system using exothermic fluid to melt and solidify the low-melt alloy. This substitution eliminates the need for extensive mud removal operations while ensuring reliable sealing, as the thermal process is not affected by the presence of drilling fluids

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

2Reliability

If metal or alloy plugs are used to meet regulatory requirements, then sealing across hydrocarbon-bearing formations is improved, but the complexity of the plugging operation increases

Engineering Contradiction:
Improveregulatory complianceVSAvoidplugging operation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The low-melt alloy plug performs multiple functions automatically: it flows to fill the annular space, expands during solidification to ensure complete coverage, and forms a gas-tight seal that meets regulatory requirements. This self-service capability eliminates the need for complex multi-step operations while ensuring regulatory compliance

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention uses a composite approach combining low-melt alloy with exothermic fluid, where the exothermic fluid provides the thermal energy needed to melt and redistribute the alloy material. This composite system achieves reliable sealing across hydrocarbon-bearing formations while simplifying the overall operation compared to traditional metal plug methods

Inventive Principle:
Principle #40Composite materials

3Reliability

If casing is removed to access the annulus for plugging, then proper plugging can be achieved, but the time and cost of the operation increases

Engineering Contradiction:
Improveplugging effectivenessVSAvoidoperation duration
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention extracts only the necessary function of casing removal by using perforations to access the annular space rather than completely removing the casing. This selective extraction maintains plugging effectiveness while dramatically reducing operation time and cost compared to full casing removal

Inventive Principle:
Principle #2Taking out (Extraction)

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

This approach eliminates the need for extensive mud removal and allows for secure, cost-effective plugging with minimal equipment, enabling efficient well abandonment and compliance with regulatory requirements by forming a permanent, gas-tight seal.

Implementation Method 1

deploying an exothermic fluid downhole, wherein activation of the exothermic material liquefies the plugging material

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Implementation Method 2

activation of the exothermic material liquefies the plugging material; allowing the plugging material and the exothermic fluid to solidify form a cast-in-place plug

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

activation of the exothermic material liquefies the plugging material; allowing the plugging material and the exothermic fluid to solidify form a cast-in-place plug

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 4

which expands to create a secure seal

Methodology Applied
Scientific EffectExpansion: Thermal Expansion

Data Source

PatentEP3724445B1P&a setting with exothermic material
Publication Date: 2022.01.26 CONOCOPHILLIPS CO
  • EP3724445B1 patent drawingFigure 1A~1C
  • EP3724445B1 patent drawingFigure 1D~1E
  • EP3724445B1 patent drawingFigure 1F~1G

AI summary

A method of plugging a hydrocarbon well includes deploying a downhole tool to remove at least a portion of a casing at a section of well to be plugged. Deploying a blocking device downhole to block a bottom of the section of well to be plugged. Deploying a plugging material downhole onto the blocking device to fill an area to be plugged. Deploying an exothermic fluid downhole, wherein activation of the exothermic material liquefies the plugging material. Allowing the plugging material and the exothermic fluid to solidify form a cast-in-place plug that fills the section of well to be plugged.