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Shock & Vibration Training

This document provides an overview of shock and vibration training for drilling clients. It defines shock and vibration, describes various monitoring tools, classifies different types of shocks and vibrations like axial shocks and torsional vibrations. The document discusses how to diagnose issues like bit whirl and stick-slip using downhole measurements and surface parameters. It also outlines potential cures for downhole vibrations and emphasizes that thorough analysis is needed to improve drilling efficiency and success. The overall goal is to optimize the drilling process by increasing efficiency while reducing damage and costs.

Uploaded by

Dante Schneider
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© © All Rights Reserved
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Download as PDF, TXT or read online on Scribd
Download as pdf or txt
319 views24 pages

Shock & Vibration Training

This document provides an overview of shock and vibration training for drilling clients. It defines shock and vibration, describes various monitoring tools, classifies different types of shocks and vibrations like axial shocks and torsional vibrations. The document discusses how to diagnose issues like bit whirl and stick-slip using downhole measurements and surface parameters. It also outlines potential cures for downhole vibrations and emphasizes that thorough analysis is needed to improve drilling efficiency and success. The overall goal is to optimize the drilling process by increasing efficiency while reducing damage and costs.

Uploaded by

Dante Schneider
Copyright
© © All Rights Reserved
Available Formats
Download as PDF, TXT or read online on Scribd
Download as pdf or txt
Download as pdf or txt
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Shock & Vibration Training For Clients

Theory

Optimizing Drilling Process


by increasing efficiency, reducing
damage
And saving cost
Shock & Vibration Training For Clients

Agenda

Shock and Vibration Definition

Monitoring Tools and Detection

Shock and Vibration Classification

Drillstring Stability Summary

Conclusion
Shock and Vibration Definition

Shock in a drilling environment is


the sudden input of energy, when
the BHA, bit or drillstring impacts
with the borehole.

Vibrations are the response of


the bit/BHA/drillstring to the
shock.
Shock and Vibration Monitoring Tools
Shock Detection - Downhole

Shock is characterized by:


Magnitude (deceleration which the tool undergoes as it impacts the
Borehole measured in G’s)

Duration ( shock event interval, measured in seconds)

Frequency (number of times when a Shock greater than its Threshold.


Known as CPS (Counts Per Second))
Comparison of the G-force

The vehicle coming to a stop in 4 feet from


60 MPH speed would generate
approximately a 30 G deceleration

Fighter pilots in combat maneuvers can


undergo 8 G’s. At this level of acceleration,
the pilot’s body is pushed against the seat.

The shock magnitude registered via


MWD/LWD tools sometimes exceeds 200 G.
Schlumberger Shock Risk Level Standards

All Commercial tools have


threshold of 50 G

Standard frequency of
shock counts except
SlimPulse tool

Comprehensive software
to flag potential problem
Schlumberger Shock Risk Level Standards
Shock and Vibration Classification

Torsional
Bit Whirl
Shocks
Axial Shocks

Diagnostics
Top Drive Shaking
Kelly Bouncing
Downhole shocks registered via M/LWD Tools

Results
Broken Bit Cutters, Slow ROP, Damaged Equipment

Cure
Stop. Pull of bottom. Reduce RPM. Back on bottom.
Increase WOB
Run Shock Sub to absorb axial movement
Change the bit type
Lateral Shocks

Diagnostics
Downhole shocks registered via M/LWD Tools

Results
Broken BHA Components
Damaged Bit

Cure
Stop. Pull of bottom. Let the drillstring stabilize
Including Stabilizers in the BHA
Vary Drilling Parameters
Shocks Diagnostics and Cure

Increase in WOB reduces Lateral


Shocks High Lateral
Shocks

Reduced Lateral
Shocks
Torsional Shock and Mode Coupling

Diagnostics
Downhole shocks registered via
M/LWD Tools

Results
Overtorque of tool joints
Damaged connections
Broken BHA Components

Cure
Stop drilling. Stabilize Drillstring
Vary Drilling Parameters
Torsional Shocks Diagnostics and Cure

Lateral Shocks induce


Torsional Vibration

Increased Torque and WOB drop


directly responded on reduced
ROP and increased Lateral and
Torsional Shocks
Increase WOB and
stabilize the drillstring
resulted in shock
reduction
BHA Whirl
BHA Whirl - Eccentric rotation about a point other than its
geometric center caused by bit / BHA and wellbore
“gearing”.

Type of BHA Whirl


Forward, Backward, Chaotic

Diagnostics:
Lateral Shocks detection via downhole tools
Increased surface torque
Results:
Damaged downhole equipment
Overgauge hole
BHA Twist-off
Cure:
Stop drilling. Vary drilling parameters
Use stiffer BHA
BHA Whirl Diagnostics

Surface Torque correlating with Shocks


indicating BHA Whirl

Continues High Shocks and Surface Torque


resulted in BHA Twist Off
Bit Whirl

Diagnostics
Downhole shocks registered via M/LWD Tools
High torsional vibration
Low ROP

Results
Damaged bit
Overgauged hole
Spiral wellbore

Cure
Stop drilling. Restart with slower RPM
Change the bit type (less aggressive, high stability
anti-whirl)
Near bit stabilization
StickSlip

Stick Slip is ultimately the rotational slowing down and


acceleration of BHA components

In extreme cases, the BHA can stop or even


instantaneously reverse its direction
StickSlip Detection and Severity

Cutting forces impart reactive


torque in opposition to bit
rotation

Reactive torque “winds-up” the


drill string forcing it to vibrate

Stickslip is estimated when


compared with surface RPM
Stickslip Diagnostics and Results

Diagnostics
Stickslip indication via downhole tool
measurements
Surface torque and RPM fluctuations
Overgauge hole via LWD tool caliper
measurements
Results
Drillstring fatigue and premature failure
Bit damage
Overgauge hole
Stabilizer damage
Cure
Reduce WOB and Increase RPM
Use of less aggressive bit
Roller reamer in BHA
Add mud lubricant
Effect of Lubricity on StickSlip

High StickSlip,
Fluctuation Added Mud
RPM, Lubricant
Inconstant ROP

Constant RPM,
Low StickSlip
High ROP
Drill String Stability Summary

Good Shock and Vibration do not


exist

Different vibrational mechanisms


could be induced due to varying
drilling parameters such as WOB
and RPM

Thorough analysis of downhole


shock measurements, diagnostic of
drilling environment and BHA
factors are vital for to overall
drilling success
Diagnosis and Potential Cures for Downhole Vibration
Conclusion

Good Shock and Vibrations do not exists

Shock and Vibration means higher drilling cost

Downhole measurements are more reliable since surface


parameters are not always affected by Shock and Vibration

Controlled situation with Shock and Vibration will always


help to improve drilling efficiency

Good understanding of Surface and Downhole


measurements are necessary to identify Shock and Vibration
mechanisms

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