Stepped PDC Cutter Elements for Higher Drill Bit Penetration

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Solution Overview

Problem

Existing fixed cutter drill bits face challenges in cutting efficiency and durability, leading to increased drilling time and costs due to frequent bit changes, which are influenced by the cutting efficiency and exposed surface area of the cutter elements.

Innovation Solution

The drill bit design incorporates cutter elements with non-planar cutting faces featuring multiple cutting edges and orientations to enhance cutting efficiency and durability, including a primary and secondary cutting surface configuration to improve engagement with the formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If cutter elements with single cutting edge are used, then the structure is simple and easy to manufacture, but the cutting efficiency and durability are reduced

Engineering Contradiction:
Improvecutting efficiencyVSAvoidcutter element structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The cutting face of the cutter element is segmented into multiple cutting edges (primary, secondary, and tertiary cutting edges) arranged at different positions and orientations. This segmentation allows each edge to engage the formation at different stages of rotation, maintaining continuous cutting action and improving overall cutting efficiency without requiring complete replacement of the cutter element

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a single-planar cutting edge to a multi-dimensional cutting face structure with edges positioned at different heights, angles, and radial distances from the cutter element axis. This dimensional expansion creates multiple cutting surfaces that engage the formation at different points in the rotation cycle, significantly enhancing cutting efficiency

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If cutter elements with larger exposed surface area are used, then the cutting efficiency is improved, but the durability and lifespan are reduced due to faster wear

Engineering Contradiction:
Improverate of penetrationVSAvoidcutter element lifespan
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The cutting face is divided into multiple cutting edges that can wear independently. As primary cutting edges wear, secondary and tertiary edges remain intact and can continue cutting, effectively extending the operational life of the cutter element while maintaining high rate of penetration throughout its service life

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design allows progressive discarding of worn cutting edges while recovering functionality through the use of remaining unused edges. The cutter element is not discarded entirely after one edge wears, but continues to perform through secondary edges, maximizing utilization of the cutter element material

Inventive Principle:
Principle #34Discarding and recovering

3Duration of action of stationary object

If multiple cutting edges are added to cutter elements, then the lifespan is extended, but the manufacturing complexity and cost increase

Engineering Contradiction:
Improvedrill bit lifespanVSAvoidcutter element manufacturing
Core Design Contradiction:
Duration of action of stationary objectVSEase of manufacture

Solution Approach 1:

Multiple cutting edges are pre-formed on the cutter element during manufacturing at different positions and orientations. This preliminary action ensures that when the drill bit is deployed, multiple functional edges are already available, extending lifespan without requiring complex field adjustments or replacements

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention varies geometric parameters of the cutting face (edge positions, angles, radial distances, and orientations) to create multiple cutting edges from a single cutter element body. These parameter variations are achieved through controlled manufacturing processes that shape the cutting face geometry, extending lifespan through design optimization rather than material quantity increase

Inventive Principle:
Principle #35Parameter changes

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 improved cutter element design enhances cutting efficiency and extends the drill bit's lifespan, reducing the frequency of bit changes and lowering drilling costs by maintaining a high rate of penetration and increasing the effective diamond surface area during drilling.

Implementation Method 1

each cutter element typically has a hard cutting layer of polycrystalline diamond or other superabrasive material

Methodology Applied
Scientific EffectAbrasion: Abrasion

Implementation Method 2

The drilling fluid exiting the face of the bit through nozzles or ports performs several functions. In particular, the fluid removes formation cuttings (for example, rock chips) from the cutting structure of the drill bit

Methodology Applied
Scientific EffectFluid flow transport: Advection

Implementation Method 3

Still further, the drilling fluid removes heat, caused by contact with the formation, from the cutter elements to prolong cutter element life

Methodology Applied
Scientific EffectConvection cooling: Convection

Implementation Method 4

the drilling fluid removes heat, caused by contact with the formation, from the cutter elements

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4526544B1Fixed cutter drill bits and cutter elements with secondary cutting edges for same
Publication Date: 2026.04.15 NAT OILWELL VARCO LP
  • EP4526544B1 patent drawingFigure 1
  • EP4526544B1 patent drawingFigure 2
  • EP4526544B1 patent drawingFigure 3

AI summary

A cutter element for a fixed cutter drill bit (100) configured to drill a borehole (20) in a subterranean formation (90) includes a base (210) having a central axis, a first end (210a), a second end (210b), and a radially outer cylindrical surface extending axially from the first end to the second end. In addition, the cutter element includes a cutting layer (220) fixably mounted to the first end (210) of the base. The cutting layer includes a stepped cutting face (221) distal the base and a radially outer cylindrical surface extending axially from the cutting face to the radially outer cylindrical surface of the base. The radially outer cylindrical surface of the cutting layer is contiguous with the radially outer cylindrical surface of the base. The stepped cutting face includes a first step (230), a second step (240) axially spaced from the first step, and a riser axially positioned between the first step and the second step. The first step is axially positioned between the riser and the base.