› chapters › files › Houston_Failure... FAILURE ANALYSIS FAILURE ANALYSIS …Schlumberger Private 1 Nash Asrar,Ph.D Materials Support and Failure Analysis Group EMS Centers,
Post on 27-Feb-2020
32 Views
Preview:
Transcript
Sc
hlu
mb
erg
er P
rivate
1
Nash Asrar,Nash Asrar,Nash Asrar,Nash Asrar, Ph.DMaterials Support and Failure Analysis Group
EMS Centers, Sugar Land, TX – 77478
SMTA Expo & Tech Forum, Stafford Center, Houston, March 6, 2014
FAILURE ANALYSIS FAILURE ANALYSIS FAILURE ANALYSIS FAILURE ANALYSIS –––– Cause Cause Cause Cause
to Preventionto Preventionto Preventionto Prevention
Sc
hlu
mb
erg
er P
rivate
2
� FAILURE AND FAILURE ANALYSIS
� CONDUCTING FAILURE ANALYSIS
� TOTAL FAILURE MANAGEMENT – A Failure Prevention Process
� FAILURE OF FAILURE ANALYSIS
� EFFECTIVNESS of FAILURE MANAGEMENT – Success Stories
� CONCLUDING REMARKS
TopicsTopicsTopicsTopics
Sc
hlu
mb
erg
er P
rivate
3
Why Do Failures Occur??Why Do Failures Occur??Why Do Failures Occur??Why Do Failures Occur??
� Aggressive operation conditions (use or misuse)
� Improper maintenance (intentional or unintentional)
� Improper testing or inspection
� Assembly errors
� Fabrication/manufacturing errors
� Design errors (stress, material selection, and
assumed material condition or properties)
Sc
hlu
mb
erg
er P
rivate
4
Failure: A part in service –
� has become completely inoperable , or
� is still operable but incapable of satisfactorily performing
its intended function, or
� has deteriorated seriously, to the point that it has
become unreliable or unsafe for continued use.
Failure Analysis:
Failure analysis is an engineering approach to determining how and
why (cause and root cause) an equipment or a component has failed.
Failure and Failure AnalysisFailure and Failure AnalysisFailure and Failure AnalysisFailure and Failure Analysis
Sc
hlu
mb
erg
er P
rivate
Failure analysis has four major objectives:
� Understanding that failure occurred
� Determine the symptoms or the apparent manner a component has
failed (the mode)
� Determine the mechanism, primary cause(s) and root cause of the
failure
� Recommend feasible corrective and preventive action(s)
…..Failure analysis is a journey, prevention is the goal….March 12, 2014 5
Aims and ObjectivesAims and ObjectivesAims and ObjectivesAims and Objectives
Sc
hlu
mb
erg
er P
rivate
March 12, 2014 6
Conducting Failure Analysis (FA) Conducting Failure Analysis (FA) Conducting Failure Analysis (FA) Conducting Failure Analysis (FA) ––––
a science and an arta science and an arta science and an arta science and an art
Sc
hlu
mb
erg
er P
rivate
7
Sc
hlu
mb
erg
er P
rivate
� The failure investigation report is expected to answer two questions:
“What is the problem?” and “What is the root cause of the problem?”
� Conclusion(s) must be brief, clear and adequately supported by
findings/test results provided in the report.
� In recommendation(s) FA engineer suggests the “best” solution to
prevent the failure in the future and failures of similar equipment.
� Recommended optimal corrective action(s) must address the root
cause of the problem, be technically feasible, cost effective and
timely (good compromise of quality and time).
March 12, 2014 8
Concluding Failure AnalysisConcluding Failure AnalysisConcluding Failure AnalysisConcluding Failure Analysis
Sc
hlu
mb
erg
er P
rivate
March 12, 2014 9
FailureFailureFailureFailure----Prevention ProcessPrevention ProcessPrevention ProcessPrevention Process
Sc
hlu
mb
erg
er P
rivate
Failure analysis is a journey, PREVENTION is the Failure analysis is a journey, PREVENTION is the Failure analysis is a journey, PREVENTION is the Failure analysis is a journey, PREVENTION is the goalgoalgoalgoal
10
FailureFailureFailureFailure
Failure AnalysisFailure AnalysisFailure AnalysisFailure AnalysisIdentification of cause and root cause of the
failure
PreventionPreventionPreventionPreventionImplementation of findings/learning of failure
analysis
Sc
hlu
mb
erg
er P
rivate
11
Concepts Of Failure AnalysisConcepts Of Failure AnalysisConcepts Of Failure AnalysisConcepts Of Failure Analysis
� Mission - Find out how the
failure occurred
� Purpose - Determine the cause
of the failure
� Affiliation - Not regarded as an
integral part of the
product development
and manufacturing
process
- Prevention
- Determine the root cause of
the failure
- Regarded as an integral
part of the product
development and
manufacturing process
Traditional Modern
Sc
hlu
mb
erg
er P
rivate
March 12, 2014 12
Cause and EffectCause and EffectCause and EffectCause and Effect
Effect Cause
Injury Caused By Fall
Fall Caused By Slipped
Slipped Caused By Wet surface
Wet surface Caused By Leaky valve
Leaky valve Caused By Seal Failure
Seal Failure Caused By Not maintained
Sc
hlu
mb
erg
er P
rivate
March 12, 2014 13
The Elemental Causal SetThe Elemental Causal SetThe Elemental Causal SetThe Elemental Causal Set
EffectEffectEffectEffect
Open fire
ConditionConditionConditionCondition
Oxygen, etc.
ConditionConditionConditionCondition
Combustible
material
ConditionConditionConditionCondition
Match exists
ActionActionActionAction
Match strike
EffectEffectEffectEffect
ConditionConditionConditionCondition
ActionActionActionAction
Caused
ByCaused
By
Elemental Causal Set
Example:
Why open fire?
Sc
hlu
mb
erg
er P
rivate
� Elemental causal set is the fundamental causal element of all that
happens. It is made up of an “effect” and its immediate cause, which
consists of an action and one or more conditions.
� Actions are momentary cause that bring conditions together to
cause an effect – Most easily recognized.
� Conditions are causes that exist over time prior to the companion
action – often ignored.
� Effect can be prevented by eliminating either action or conditions or
preventing them from combining. Example - Application of coating (a
barrier layer) for corrosion control.
March 12, 2014 14
The Elemental Causal SetThe Elemental Causal SetThe Elemental Causal SetThe Elemental Causal Set
Sc
hlu
mb
erg
er P
rivate
15
Cause Cause Cause Cause vsvsvsvs Root CauseRoot CauseRoot CauseRoot Cause
Primary cause
� Set of conditions or
parameters from which the
failure began
� For short term solution
Root Cause
� A process or procedure which
went wrong
� For long term solution
Hidden root
cause(s)
Evident
cause(s)
Systems and
indicators
Key point is that this is not typically obvious and often has not
been considered ……and most often hidden from view
Sc
hlu
mb
erg
er P
rivate
16
Collapse of a Building
Primary cause – Use of poor
quality of cement
Root cause – Budget constraint
OR poor specs, bad supplier, bad management, poor QC…..
Cause Cause Cause Cause vsvsvsvs Root CauseRoot CauseRoot CauseRoot Cause
Sc
hlu
mb
erg
er P
rivate
March 12, 2014 17
Difference between Primary Cause and Root Cause
Primary Cause (set of
conditions or parameters)Root Cause (process or procedure)
The finish on a machine part
was not as specified
The failure to check the finish after parts are
machined
The incorrect heat treatment
was applied
The failure to ensure that the heat treatment
furnace had sufficient control of changes in
temperature to produce the desired
microstructure and mechanical properties in
the part/component.
Corrosion and cracking of
drilling tools due to corrosive
environment
Lack of implementation of guidelines to
control corrosivity of environment (drilling
fluids).
Manufacturing defect of
component X, Y, Z….
Lack of a procedure to ensure provision of
proper instruction/design to the manufacturer
and/or lack of procedure for QC (quality
check)
Sc
hlu
mb
erg
er P
rivate
� TFM is a process through which knowledge of failure
mechanisms can be applied and lessons learned can be
implemented to reduce or prevent failure.
� Components of TFM;
� Failure mechanism investigation
�Root cause analysis
� Implementation of the lessons learned March 12, 2014 18
Total Failure Management (TFM)Total Failure Management (TFM)Total Failure Management (TFM)Total Failure Management (TFM)
Failure AnalysisFailure AnalysisFailure AnalysisFailure Analysis
Failure Failure Failure Failure
ManagementManagementManagementManagement
Sc
hlu
mb
erg
er P
rivate
March 12, 2014 19
Steps of TFM Objectives
Failure
Mechanism
Investigation
Sample/site preservation Ensure the correct physical evidence
is collected and analyzed properly to
determine the physical cause of failure
or failure mechanism
Failed sample collection
Data collection and integration
Laboratory analysis
Reporting/documentation
Root cause
determination
Cause and effect analysis Determine the root cause (process or
procedure) that allowed the failure to
occur
Causal factor charting
Root cause identification
Recommendations
Implementing
lessons learned
Develop engineering solutions Ensure that lessons learned are
implemented as solutions and
embedded in the organizational
culture
Communication
Action tracking
Feed back to FM system
Total Failure Management (TFM)Total Failure Management (TFM)Total Failure Management (TFM)Total Failure Management (TFM)
Sc
hlu
mb
erg
er P
rivate
March 12, 2014 20
Total Failure Management (TFM)Total Failure Management (TFM)Total Failure Management (TFM)Total Failure Management (TFM)
Sc
hlu
mb
erg
er P
rivate
March 12, 2014 21
Failure of Failure AnalysisFailure of Failure AnalysisFailure of Failure AnalysisFailure of Failure Analysis
Sc
hlu
mb
erg
er P
rivate
March 12, 2014 22
In the following situations or work behavior, objectives of the failure
analysis may not be achieved:
� Assuming a primary/apparent cause to be the root cause
� Determining the failure cause by assumption
� Collecting insufficient information, collecting sample from wrong
location and ending an analysis before it is completed
� Refusing to recognize that a failure can or does exist
� Shutting down the malfunctioning equipment
� Discarding failed parts
� No documentation
Sc
hlu
mb
erg
er P
rivate
23
Achievements of Failure AnalysisAchievements of Failure AnalysisAchievements of Failure AnalysisAchievements of Failure Analysis
Sc
hlu
mb
erg
er P
rivate
24
Electronic Components Failure
Killer Gold – Embrittlement and Whiskers
� Irregular and large voids in Pb-
Free (SN96) solder
� Gold content in solder >9wt.%
Sc
hlu
mb
erg
er P
rivate
25
AuSn4
Ag3Sn
• 100 thermal cycles at - 40oC to 155oC
• Formation of brittle crystals of Au-rich (light grey) and Ag-rich IMC (grey)
Electronic Components Failure
Killer Gold – Embrittlement and Whiskers
Sc
hlu
mb
erg
er P
rivate
26
Tin-Whiskers on Pb-Free solder
• Whisker formation during the thermal cycle at - 40oC to 180oC
• Islands of Sn-Ni-Au IMCs in the solder matrix
Sc
hlu
mb
erg
er P
rivate
27
Plotted for SnPb 60/40 solder
RESOLUTION
� Gold plating thickness for solder joints = 2 - 10 microinches immersion gold layers are adequate to offer solderability.
� Gold content in solder = 3 wt.% max
Electronic Components Failure
Killer Gold – Embrittlement and Whiskers
Sc
hlu
mb
erg
er P
rivate
28
Prevention of Field Failure
Corrosion of the Drill Collar(Drill Collar ENP001 and ENP004 failed at the RIG)
pH of the drilling fluid
• reported = 10
• determined = 8.8
Dissolved oxygen (DO)
• Mud was not treated with oxygen scavenger
• Degasser was out of service
• Determined 4.36 ppm DO in the mud
H2S in the downhole fluid
• Mud was contaminated with 15ppm H2S
• Mud was not treated with sulfide scavenger.
Collar cleaning after POOH
• With high pressure brakish water
EXCESSIVEEXCESSIVEEXCESSIVEEXCESSIVE
CORROSION CORROSION CORROSION CORROSION
andandandand
CRACKINGCRACKINGCRACKINGCRACKING
Sc
hlu
mb
erg
er P
rivate
29
COLLAR - Excessive corrosion and cracking on the OD and ID surfaces
Prevention of Field Failure
Corrosion of the Drill Collar(Drill Collar ENP001 and ENP004 failed at the RIG)
Sc
hlu
mb
erg
er P
rivate
30
CHASSIS - Excessive corrosion pitting on the OD surface
Prevention of Field Failure
Corrosion of the Drill Collar(Drill Collar ENP001 and ENP004 failed at the RIG)
Sc
hlu
mb
erg
er P
rivate
31
• High pressure pumps and clean water was made available
RESOLUTIONS
pH of the drilling fluid
• Proper alkali dosing
• Determined = 10 by HACH’s pH every 4 hr.
Dissolved oxygen (DO)
• Mud was treated with oxygen scavenger
• Degasser was repaired
• Determined <1ppm DO in the mud
H2S in the downhole fluid
• Mud was treated with sulfide scavenger
• H2S was eliminated
Collar cleaning after POOH
• High pressure pumps and clean water was made available
NEGLIGBLE
CORROSION
Prevention of Field Failure
Corrosion of the Drill Collar
Sc
hlu
mb
erg
er P
rivate
32
Negligible corrosion
Prevention of Field Failure
Corrosion of the Drill Collar(Drill Collar ENP001 and ENP004 failed at the RIG)
Sc
hlu
mb
erg
er P
rivate
33
Field Failure
Corrosion Control of the Drill Collar - Qatar
0
5
10
15
20
25
30
35
40
0
5
10
15
20
25
30
35
40
45
25 40 36
2006 2007 2008
Nu
mb
er
of
Co
lla
rs D
am
ag
ed
Nu
mb
er
of
Co
lla
rs D
am
ag
ed
Nu
mb
er
of
Co
lla
rs D
am
ag
ed
Nu
mb
er
of
Co
lla
rs D
am
ag
ed
Worn out
corroded
Cracked
Job Count
avg/month
After implementation of corrosion
control guidelines for mud
treatment and tool cleaning:
• Collar damages per job has
reduced
• Service life of the collar
raised from 800 hrs (2005 –
2007) to 2000 hrs (2008)
Sc
hlu
mb
erg
er P
rivate
34
Concluding RemarksConcluding RemarksConcluding RemarksConcluding Remarks
� Failure Analysis + Failure Management = Failure Prevention
� Failure analysis is a journey, PREVENTION is the goal
� Failure analysis is a science and an art
Sc
hlu
mb
erg
er P
rivate
March 12, 2014 35
Concluding RemarksConcluding RemarksConcluding RemarksConcluding Remarks
Actions Required
� Adoption - Adopt the modern concept of failure analysis.
� Documentation - Eliminate the errors of knowledge by
developing quality documentation, and sharing information.
� Implementation - Develop a process to ensure the
implementation of the corrective measures � Follow TFM.
Sc
hlu
mb
erg
er P
rivate
Thanks!
36
Questions
top related