Curved PDC Cutting Elements for Impact Damage Reduction

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Solution Overview

Problem

Earth-boring tools with conventional cutting elements suffer from impact damage and wear, leading to dulling and loss of cutting efficiency due to chipping and spalling of polycrystalline diamond compact (PDC) cutting tables during subterranean drilling.

Innovation Solution

The cutting elements feature a substrate with polycrystalline superabrasive material having multiple transition surfaces and a curved stress-reduction feature on the second transition surface, designed to reduce peak collision forces and induce beneficial stress states, thereby enhancing durability and cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fixed cutting elements are used, then manufacturing simplicity is maintained, but impact damage and chipping occur leading to reduced reliability

Engineering Contradiction:

Improveresistance to impact damageVSAvoidcutting element structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies curvature by replacing conventional flat or angular cutting element surfaces with curved surfaces. Specifically, the cutting element includes a curved face and a curved edge surface that transitions between the curved face and the substrate. This curvature distributes impact forces more evenly across the cutting element, reducing stress concentration and resistance to impact damage and chipping.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Strength

If conventional cutting element geometry is used, then manufacturing simplicity is maintained, but peak collision forces cause chipping and spalling

Engineering Contradiction:

Improveresistance to chipping and spallingVSAvoidcutting element fabrication

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The curved face and curved edge surface distribute collision forces more uniformly, reducing peak stresses that cause chipping and spalling. The curved geometry eliminates sharp corners and edges where stress concentration would occur, thereby improving strength and damage resistance.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent changes the geometric parameters of the cutting element by introducing curved surfaces with specific radii of curvature. These parameter changes alter the stress distribution characteristics, reducing peak collision forces and improving resistance to chipping and spalling.

Inventive Principle:

Principle #35Parameter changes

3Temperature

If conventional flat surfaces are used, then manufacturing simplicity is maintained, but cooling efficiency is reduced

Engineering Contradiction:

Improvecooling efficiencyVSAvoidsurface geometry

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The curved face and curved edge surface increase the surface area of the cutting element exposed to cooling fluids. The curvature creates a more favorable flow path for cooling fluids, enhancing heat dissipation and cooling efficiency compared to conventional flat surfaces.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Data Source

PatentUS10914124B2Cutting elements comprising waveforms and related tools and methods

Publication Date: 2021.02.09 BAKER HUGHES CO

AI summary

Cutting elements for earth-boring tools may include a polycrystalline, superabrasive material secured to an end of a substrate. The polycrystalline, superabrasive material may include a first transition surface and a second transition surface. A waveform may extend around a circumference of the second transition surface, a surface of the waveform tapered toward from the substrate and extending radially from the second transition surface toward the central axis. The surface of the waveform may extend from the second transition surface to a planar surface of the polycrystalline located at a same distance from the substrate as troughs of the waveform surface, the planar surface oriented perpendicular, and located proximate, to the central axis.