Non-magnetic Hardfacing for Drill String Wear Resistance

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Solution Overview

Problem

Downhole tools and components for oil and natural gas wells require wear resistance and fracture toughness while minimizing magnetic permeability to avoid interference with sensitive instrumentation, as existing hardfacing materials often have high magnetic permeability.

Innovation Solution

A non-magnetic, abrasive wear-resistant hardfacing material is applied to drill string members, comprising sintered carbides dispersed in a non-magnetic matrix alloy, which is heated and solidified to form a layer with reduced magnetic permeability, suitable for use in areas with sensitive drilling instruments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional hardfacing materials are used to provide wear resistance and fracture toughness, then the drill string member achieves high wear resistance, but the magnetic permeability increases and interferes with sensitive downhole instrumentation

Engineering Contradiction:
Improvewear resistanceVSAvoidmagnetic permeability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies composite materials by combining non-magnetic carbide particles (providing wear resistance) with a non-magnetic metal matrix alloy (providing fracture toughness and low magnetic permeability). This composite structure achieves both high wear resistance and reduced magnetic interference, resolving the contradiction between protective performance and magnetic compatibility for downhole instrumentation.

Inventive Principle:
Principle #40Composite materials

2Strength

If hardfacing material is applied by melting the matrix to achieve adequate fracture toughness, then the hardfacing material achieves proper bonding and toughness, but magnetic permeability increases due to conventional matrix materials

Engineering Contradiction:
Improvefracture toughnessVSAvoidmagnetic permeability
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by selecting a non-magnetic metal matrix alloy with specific compositional parameters (low magnetic permeability) while maintaining the melting and solidification process to achieve adequate fracture toughness. The matrix material parameters are changed to be non-magnetic, allowing the hardfacing to be applied through conventional thermal processes without introducing magnetic interference.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If non-magnetic materials are used to reduce magnetic permeability, then magnetic interference with instrumentation is reduced, but wear resistance and fracture toughness may be compromised

Engineering Contradiction:
Improvemagnetic permeabilityVSAvoidwear resistance
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent uses composite materials to combine non-magnetic carbide particles (providing wear resistance) with a non-magnetic metal matrix alloy (providing fracture toughness). This composite approach ensures that reducing magnetic permeability does not compromise wear resistance, as both functions are provided by different components of the composite hardfacing material.

Inventive Principle:
Principle #40Composite materials

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 enhanced wear resistance and fracture toughness while maintaining reduced magnetic permeability, ensuring compatibility with sensitive drilling instruments and optimizing their performance.

Implementation Method 1

heating a portion of the non-magnetic hardfacing precursor material to a temperature above the melting point of the matrix material to melt the matrix material

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

solidifying the molten non-magnetic matrix material to form a layer of a non-magnetic hardfacing material

Methodology Applied
Scientific EffectSolidification: Freezing

Data Source

PatentEP2668362B1Non-magnetic drill string member with non-magnetic hardfacing and method of making the same
Publication Date: 2020.01.01 BAKER HUGHES CO
  • EP2668362B1 patent drawingFigure 1~2
  • EP2668362B1 patent drawingFigure 3~4
  • EP2668362B1 patent drawingFigure 5~6

AI summary

A method for applying a non-magnetic, abrasive, wear-resistant hardfacing material to a surface of a drill string member includes providing a non-magnetic drill string member formed of a non-magnetic material, the drill string member having an outer surface. It also includes providing a non-magnetic hardfacing precursor material comprising a plurality of non-magnetic, sintered carbide pellets and a non-magnetic matrix material; heating a portion of the non-magnetic hardfacing precursor material to a temperature above the melting point of the matrix material to melt the matrix material. It further includes applying the molten non-magnetic matrix material and the plurality of non-magnetic, sintered carbide pellets to the exterior surface of the drill string member; and solidifying the molten non-magnetic matrix material to form a layer of a non-magnetic hardfacing material having a plurality of non-magnetic, sintered carbide pellets dispersed in the hardfacing material.