Suspension Sub Vibration Control for Rock Drilling

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Solution Overview

Problem

Current rock drilling technologies face inefficiencies when transitioning between soft and hard formations, requiring frequent bit changes and increased rig deployment time due to the need for different drilling modes.

Innovation Solution

A passively induced forced vibration rock drilling system utilizing a bottomhole assembly with a suspension sub that includes a stator barrel, traveler barrel, slip joint, torsional joint, and Belleville washers to dampen or resonate the drill bit's vibration, allowing efficient operation in both soft and hard formations without the need for bit changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If different drill bits are used for soft and hard formations, then drilling efficiency in each formation type is improved, but the frequency of bit changes and rig deployment time increase

Engineering Contradiction:
Improvedrilling efficiencyVSAvoidrig deployment time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The drill bit is designed with dual functionality to operate efficiently in both soft and hard formations. The bit incorporates both roller cones for hard formations and cutting elements for soft formations, allowing a single bit to perform multiple drilling functions without requiring frequent changes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The drill bit design allows dynamic adaptation to different formation types through the interaction of roller cones and cutting elements. The roller cones can penetrate hard formations while cutting elements engage soft formations, creating a dynamic system that automatically adjusts to formation conditions without requiring bit changes.

Inventive Principle:
Principle #15Dynamics

2Loss of time

If a single drill bit design is used for both soft and hard formations, then rig deployment time is reduced, but drilling efficiency in specific formations decreases

Engineering Contradiction:
Improverig deployment timeVSAvoiddrilling efficiency
Core Design Contradiction:
Loss of timeVSProductivity

Solution Approach 1:

The drill bit integrates multiple cutting mechanisms (roller cones and cutting elements) into a single universal design that can effectively drill both soft and hard formations, eliminating the need for separate bit inventories and frequent bit changes while maintaining drilling efficiency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention merges two previously separate drilling mechanisms (roller cone bits for hard formations and cutting elements for soft formations) into a single integrated drill bit design, allowing both mechanisms to work together or independently based on formation conditions.

Inventive Principle:
Principle #5Merging (Combining)

3Stability of the object's composition

If drill bit vibration is dampened for soft formations, then drilling stability is improved, but percussive energy needed for hard formations is reduced

Engineering Contradiction:
Improvedrilling stabilityVSAvoidpercussive energy
Core Design Contradiction:
Stability of the object's compositionVSForce

Solution Approach 1:

The drill bit system dynamically adjusts its vibration characteristics based on formation type. In soft formations, the bit operates with dampened vibration for stability, while in hard formations, the bit generates resonant vibrations to deliver percussive energy for effective penetration.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters (vibration amplitude and frequency) based on formation conditions. For soft formations, lower vibration parameters provide stability, while for hard formations, higher vibration parameters generate the necessary percussive energy.

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

Enables continuous drilling through varying formations without the need for frequent bit changes, reducing rig deployment time and improving drilling efficiency by shifting between damping and resonant modes based on formation type.

Implementation Method 1

The suspension sub is tuned relative to the drill bit to: dampen the vibration of the drill bit when the BHA is rotated at a first angular velocity; and resonate the vibration of the drill bit when the BHA is rotated at a second angular velocity

Methodology Applied
Scientific EffectDamping: Damping

Implementation Method 2

The suspension sub is tuned relative to the drill bit to: dampen the vibration of the drill bit when the BHA is rotated at a first angular velocity; and resonate the vibration of the drill bit when the BHA is rotated at a second angular velocity

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 3

A passively induced forced vibration rock drilling system utilizing a bottomhole assembly with a suspension sub that includes a stator barrel, traveler barrel, slip joint, torsional joint, and Belleville washers to dampen or resonate the drill bit's vibration

Methodology Applied
Scientific EffectForced vibration: Driven Harmonic Oscillation

Data Source

PatentEP3258056B1Passively induced forced vibration rock drilling system
Publication Date: 2019.07.24 VAREL EURO SAS
  • EP3258056B1 patent drawingFigure 1A~1C
  • EP3258056B1 patent drawingFigure 2A~2C
  • EP3258056B1 patent drawingFigure 3A~3D

AI summary

A bottomhole assembly includes: a drill bit operable to vibrate when engaged with a formation and rotated; and a suspension sub including: a stator barrel for connection to a pipe string; a traveler barrel for connection to the drill bit; a slip joint longitudinally coupling the traveler barrel to the stator barrel while allowing movement of the traveler barrel between an extended position and a retracted position; a torsional joint connecting the traveler barrel to the stator barrel at and between the positions; and one or more springs disposed between the stator barrel and the traveler barrel. The suspension is tuned relative to the drill bit to: dampen the vibration of the drill bit when the BHA is rotated at a first angular velocity; and resonate the vibration of the drill bit when the BHA is rotated at a second angular velocity, thereby imparting percussive energy to the drill bit.