Downhole Tool Reactive Metal Degradable Resin Removal

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Solution Overview

Problem

As drilling conditions become harsh and varied, existing downhole tools lack degradability and mechanical strength, leading to increased costs and time for removal and operation, especially in deep and high-temperature environments.

Innovation Solution

A downhole tool comprising a reactive metal and a degradable resin composition, where the reactive metal degrades through chemical changes, and a degradable rubber member, allowing for controlled degradation and easy removal without the need for destructive methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional downhole tools are used in deep wells, then mechanical strength is maintained, but removal becomes difficult and costly requiring destructive methods

Engineering Contradiction:
Improveease of removalVSAvoidmechanical strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The downhole tool is divided into multiple components: a mandrel made of degradable material (polyglycolic acid or poly-L-lactic acid), a separate reactive metal component (magnesium or aluminum alloy), and a rubber member. This segmentation allows each component to serve its function independently - the degradable mandrel provides structural support while the reactive metal provides additional strength, and both can degrade separately for easy removal.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses composite material systems combining degradable polymers (polyglycolic acid, poly-L-lactic acid) with reactive metals (magnesium, aluminum alloys). These composites provide both the mechanical strength needed for deep well operations and the degradability required for easy removal. The reactive metal component specifically enhances strength while maintaining the overall degradable nature of the tool.

Inventive Principle:
Principle #40Composite materials

2Reliability

If downhole tools are designed for deep well operations, then mechanical strength and durability are improved, but removal time and cost increase

Engineering Contradiction:
Improvereliability in deep well operationsVSAvoidremoval time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The downhole tool performs self-removal through controlled degradation. The degradable mandrel automatically breaks down in the well environment without requiring external retrieval operations. The reactive metal component also degrades through chemical reactions with well fluids, further assisting in the tool's own removal process and eliminating the need for costly milling or drill-out operations.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the material parameters of the downhole tool by using degradable polymers and reactive metals that can undergo controlled chemical changes in the well environment. These parameter changes allow the tool to maintain its structural integrity during operation while automatically transitioning to a degraded state for easy removal, significantly reducing removal time from days to hours or minutes.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If degradable materials are used in downhole tools, then ease of removal is improved, but mechanical strength deteriorates

Engineering Contradiction:
Improveease of removalVSAvoidmechanical strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The invention uses composite material systems combining degradable polymers (polyglycolic acid, poly-L-lactic acid) with reactive metals (magnesium, aluminum alloys). These composites provide both the mechanical strength needed for deep well operations and the degradability required for easy removal. The reactive metal component specifically enhances strength while maintaining the overall degradable nature of the tool.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different parts of the downhole tool have different material properties optimized for their specific functions. The mandrel is made of degradable material for easy removal, while the reactive metal component provides localized strength enhancement where needed. The rubber member provides sealing and flexibility. This local quality differentiation allows the tool as a whole to achieve both strength and ease of removal.

Inventive Principle:
Principle #3Local quality

4Strength

If reactive metal is added to enhance strength, then mechanical strength is improved, but degradation control becomes more complex

Engineering Contradiction:
Improvemechanical strengthVSAvoiddegradation control complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention extracts the strength-providing function into a separate reactive metal component that is distinct from the degradable mandrel. This separation allows the reactive metal to provide enhanced strength while the mandrel handles the primary degradation function. The reactive metal's degradation is actually simpler to control than the mandrel, as it occurs through straightforward chemical reactions with well fluids, reducing overall system complexity.

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

The tool exhibits enhanced strength and degradability, reducing operational costs and time by allowing reliable drilling and effortless removal under diverse drilling conditions, eliminating the need for additional acid pumping and destructive removal methods.

Implementation Method 1

a downhole-tool member containing a reactive metal... wherein the reactive metal is a metal element alone or an alloy whose main component is the metal element that can degrade by a degradation reaction based on a chemical change

Methodology Applied
Scientific EffectChemical change:

Implementation Method 2

a downhole-tool member containing a degradable resin composition that promotes degradation of the reactive metal

Methodology Applied
Scientific EffectDegradation reaction:

Implementation Method 3

a rubber member formed of a degradable rubber... wherein the degradable rubber contains an urethane rubber

Methodology Applied
Scientific EffectChemical change:

Data Source

PatentEP3199748B1Downhole tool member containing reactive metal, downhole tool provided with downhole tool member containing degradable resin composition, and well drilling method
Publication Date: 2021.10.27 KUREHA CORPORATION
  • EP3199748B1 patent drawingFigure 1

AI summary

A downhole tool, provided with: a downhole-tool member containing a reactive metal; a downhole-tool member containing a degradable resin composition that promotes degradation of the reactive metal, preferably a degradable resin composition containing a degradable resin that generates an acid by degradation or a degradable resin composition containing a degradable resin and an inorganic substance or organic substance that promotes degradation of the reactive metal; and, as desired, a degradable rubber member. Moreover, a well-drilling method using this downhole tool.