The document summarizes the Deepwater Horizon oil spill, including causes and timeline of events. It describes: 1) The spill occurred when the Deepwater Horizon oil rig exploded on April 20, 2010, killing 11 crew and spilling over 4 million barrels of oil. 2) A series of decisions ignored warnings and best practices, compromising the well design and cementing job. This included only using 6 centralizers instead of the recommended minimum of 21. 3) Pressure tests before temporarily abandoning the well showed warning signs of integrity issues but these were ignored. The rig then exploded as hydrocarbon gases rose up the well.

1. Deepwater
Horizon Oil Spill:
Figuring out the mess
Evan Harvey, Spenser Schwabe, Robert Slack, Brandon Swartwood, Katie White 1

2. Outline
1. Introduction
2. Phenotype Description
3. Genotype Description
4. Conclusion
2

3. The Predecessor - Exxon Valdez
When and Where?
March 24, 1989
William Sound, Alaska
When?What Happened?
Exxon Valdez tanker
struck a reef spilling 11
million gallons of crude
oil
Results
Thousands of miles of
pristine waters damaged
killing marine mammals,
fish, seabirds, etc.
$2.1 Billion in costs
Introduction Phenotype Genotype Conclusion 3

4. Exxon Valdez Recommendations
● Exxon Operations Integrity Management System (OIMS)
○ Rigorous 11-point inspection designed to identify management and hazard risks
○ Monitors, benchmarks, and measures aspects of safety performance
○ Since implementation Exxon has received 10/10 rating from GovernanceMetrics
International
Introduction Phenotype Genotype Conclusion 4

5. Deepwater Horizon Oil Rig
● $350 million to build by
Transocean
● Cost $1 million per day to operate
● Maiden voyage 2001
● Backlog of rig maintenance
● Deepwater Horizon rig replaces
previous Macondo well rig
● Meant to be an exploratory vessel
● Temporary Abandonment
Introduction Phenotype Genotype Conclusion 5

6. Macondo Oil Well and BP
● Many modifications were being made due to increasing knowledge of the
geologic features
● 6 weeks behind schedule
● Over $58 million over budget
Introduction Phenotype Genotype Conclusion 6

7. Outline
1. Introduction
2. Phenotype Description
3. Genotype Description
4. Conclusion
7

8. What Happened
April 20, 2010
● 11 crew died
● Many injured
● Over 4 million barrels of oil emptied into the Gulf
Introduction Phenotype Genotype Conclusion 8

9. Lost Circulation Event
April 9, 2010
● Began to reach pay zone of hydrocarbon bearing rock
● Pressure exerted by drilling exceeded strength of formation
● Test were performed on the well
● It was determined that at least 50 million barrels of oil and gas were present
and it was worth proceeding
● Needed to prepare the well for further production by inserting either a casing
or liner
Introduction Phenotype Genotype Conclusion 9

10. Long String Casing vs. Liner
Long String Casing
● Single, continuous wall of steel that is
cemented to formation
● Took less time to install
● Original models showed that this could not
be cemented reliably so switched to liner
Liner
● Engineers often choose this option after
circulation event
● More barriers to flow of gas up annular
space
● Shorter string of casing, hangs lower in
well, anchored next to higher string
● BP resisted this and had in-house
engineers confirm Halliburton engineers
conclusion
● Cost $7-$10 million more
Introduction Phenotype Genotype Conclusion 10

11. 11

12. Centralizers on Long String Casing
● Centralizers help keep the drill pipe centered as casing is installed
● BP design originally called for 16 or more centralizers
● Halliburton engineers performed calculations and created models and
simulations that suggested at least 21 were needed
○ Only had 6 on the rig
● Alternative option was to incorporate “slip on” centralizers but BP did not
trust these
● BP’s team ignored Halliburton’s recommendations and only installed 6
centralizers for the sake of time
Introduction Phenotype Genotype Conclusion 12

13. Centralizers (Cont.)
13

14. Cementing Process
“Bottoms Up”
● Pump enough drilling mud to bring mud from the bottom of the well back to
the top at the rig
● Test for presence of hydrocarbons before cementing
● To completely circulate mud:
○ 6 - 12 hours
○ 2,760 barrels
● BP finished in 30 minutes
○ Only 350 barrels of mud
Introduction Phenotype Genotype Conclusion 14

15. Cementing Process (Cont.)
Low pumping rate
● Pumped cement at low rate of 4 barrels per minute
● Feared that increasing rate would increase risk of lost returns
Introduction Phenotype Genotype Conclusion 15

16. Cementing Process (Cont.)
Low volume
● They limited amount of cement they pumped down well
● More cement reduces risk of:
○ Contamination
○ Errors in placement
● Only pumped 60 barrels of cement
○ BP did not satisfy their own guidelines for the height of the cement column
Introduction Phenotype Genotype Conclusion 16

17. Cement Bond Log
● Tests integrity of the cement job
● BP elected to not perform this test
○ This occurred the morning of the explosion, 12 hours prior
Introduction Phenotype Genotype Conclusion 17

18. Temporary Abandonment
● Remove Deepwater Horizon riser and blowout preventer
● Procedures emailed to team the day that they would be performed
Introduction Phenotype Genotype Conclusion 18

19. 19

20. Pressure Tests
Check integrity of well and make sure there are no leaks
● Positive Test
○ Evaluates ability of casing in well to hold in pressure
● Negative Test
○ Also checks integrity of casing
○ Checks integrity of bottom hole cement job as well
Introduction Phenotype Genotype Conclusion 20

21. Positive Pressure Test
● Similar to pumping air into a bike tire to see if it will leak
● Pump fluids into well to build up pressure and see if it holds
● Pumped in pressure at 250 psi
○ Held for 5 minutes
● Increased pressure to 2,500 psi
○ Held for 30 minutes
Introduction Phenotype Genotype Conclusion 21

22. Timeline
7:30AM
Decision not to
perform cement
bond log test
10:43AM
Temporary
abandonment
procedures sent to
crew
12:00PM
Positive
pressure
test
5:00PM
Negative
pressure
test
12:00AM 10:00AM 5:00PM
12:40AM
Cement job
complete
7:00AM
22

23. Negative Pressure Test
● Isolate well by replacing drilling mud with seawater because it exerts less
pressure
○ Checks that hydrocarbons will not leak into well when the pressure is changed
● “Spacer” is pumped into well to separate mud from seawater
○ Used a new spacer they weren’t familiar with and had not tested
● Negative pressure test is performed when mud is displaced above blowout
preventer
● Pressure must stay at 0 psi after drill pipe is closed in order for it to be
successful
Introduction Phenotype Genotype Conclusion 23

24. Negative Pressure Test (Cont.)
● Drill pipe on rig is opened to release
pressure from inserting the spacer
○ Pressure should reach 0 psi
● Pressure only reached 266 psi and
then jumped to up to 1,260 psi
● Annular preventer leaking?
Introduction Phenotype Genotype Conclusion 24

25. Negative Pressure Test (Cont.)
● Performed test a second time
○ Pressure reached 0 psi but jumped back up when pipe was closed
● Third attempt → Same result
● BP Wellsite Leader (Don Vidrine) insisted running test again while
monitoring the kill line
○ Kill line pressure should be identical to drill pipe pressure
Introduction Phenotype Genotype Conclusion 25

26. Negative Pressure Test (Cont.)
● Kill line pressure = 0 psi
● Drill pipe pressure = 1,400 psi
● Wellsite leaders and crew did NOT reconcile this discrepancy
● Declared test a success
Introduction Phenotype Genotype Conclusion 26

27. Timeline (Cont.)
Should have
been monitoring
for kicks
8:00PM BP concluded
negative pressure tests
success
8:02PM Annular
preventer opened to
begin displacing mud
and spacer from riser
8:00PM
Crew had to
reroute mud
returning to rig
to active pits
27

28. Monitoring for Kicks
● Kicks are any unplanned influxes of gas or fluid
● Monitor volume of mud flow to and from pits
● Monitor volume of fluid to and from well
● Monitor rate of flow of fluid in and out of well
● Visual flow checks
○ Cameras setup to observe flow in and out of well
● Monitor drill pipe pressure
28

29. Monitoring for Kicks (Cont.)
● 9:01 pm - Drill pipe
pressure began
increasing (red line)
● 9:08 pm - Pump turned
off to perform “sheen”
test but pressure kept
increasing
● 9:14 pm - Pumps turned
back on
Introduction Phenotype Genotype Conclusion 29

30. Monitoring for Kicks (Cont.)
● Pressure increase unnoticed until 9:30 pm
● Crew tried to bleed off the pressure but it increased again
● Began decreasing at 9:39 pm
○ This meant hydrocarbons were pushing up drilling mud, up casing and into well
30

31. Timeline (Cont.)
9:40PM 9:45PM
Rerouted mud to
diverter system rather
than overboard, into
sea
9:50PM
9:49PM
EXPLOSION
9:40PM-9:43PM
Drilling mud spewing
on rig floor
9:41PM Closed annular
preventer to shut in well
but gas was already
above BOP
9:46PM Attempted
to activate blind
shear ram
31

32. 32

33. Outline
1. Introduction
2. Phenotype Description
3. Genotype Description
4. Conclusion
33

34. Root Causes
● Whitehouse Report
○ “The root causes are systemic and, absent significant reform in both industry practices and
government policies, might well recur.”
● Robert Bea
○ UC Berkeley Engineer
○ Worked on previous disasters: Nasa Columbia launch, Exxon Valdez, Hurricane Katrina
levee break
○ “There is one common thread to these disasters. They are system disasters. They are
caused by human and organizational malfunctions.”
Introduction Phenotype Genotype Conclusion 34
Man-Made
Disaster Theory

35. Root Causes
1. Decision Making
2. Organizational Culture
3. Scheduling/Budget
4. Failures of Government to provide effective regulatory oversight
5. Communication issues
Introduction Phenotype Genotype Conclusion 35

36. Decision Making
Decision to use Long String Casing after lost circulation event
● This design provided few barriers to gas flow
● The liner would have taken extra time and cost $7 - $10 million more
Introduction Phenotype Genotype Conclusion 36
Drift Toward Failure

37. Decision Making (Cont.)
● Halliburton models called for 21 centralizers
● Halliburton informed BP that using only 6 centralizers could lead to “severe
gas flow problems”
● Put cement job at risk for channeling to occur and leading to failure
● BP team members decided to ignore these models and only install 6
Introduction Phenotype Genotype Conclusion 37
Breakdown at
Boundaries
Cognitive
Tunneling

38. Decision Making (Cont.)
● Gregory Walz gave go ahead to order additional centralizers
● John Guide expressed in email he was not pleased with Walz’s decision
38
Deference to
ExpertiseFragmented
Problem Solving

39. Decision Making (Cont.)
● Brian Morel and Brett Cocales also involved in decision to ignore Halliburton
● BP did not want to waste time so only installed 6 centralizers
39
Overconfidence
Bias

40. Decision Making (Cont.)
Did NOT fully circulate the drilling mud
● Would allow them to test drilling mud for presence of gas, eliminate debris,
and prevent contamination of the cement
● Up to 12 hours to complete
Decided NOT to perform cement bond log test
● Even after Halliburton warned them about potential gas flow problems
● Would have taken 9 - 12 hours
● Tested integrity of the cement seal
Introduction Phenotype Genotype Conclusion 40
Drift Toward Failure

41. Decision Making (Cont.)
Decision to not install lockdown sleeve
● Only 2 barriers to gas flow
○ Cement seal at bottom of well
○ Seal at the wellhead at the seafloor
● Due to BP electing to install Single String Casing
Introduction Phenotype Genotype Conclusion 41
Drift Toward Failure

42. Decision Making (Cont.)
Negative Pressure Test
● Assumed problem was with kill line
● Failed to investigate discrepancy between kill line pressure and drill pipe
pressure
● Declared test a success anyways
Introduction Phenotype Genotype Conclusion 42
Lack of
Sensitivity to
Operations
No Preoccupation
with Failure
Generating a
Limited Number of
Hypotheses

43. Lack of Vigilance
Monitoring for kicks
● Monitor volume of mud flow
● Monitor volume of fluid flow
● Monitor rate of flow
● Perform visual flow checks
● Monitor pressure
43
Displacing mud and spacer from riser
● Routing mud to active pits
Attention to
Limited Number of
Cues

44. Alarm Sounding stuffs
Something about how crew tried to manually activate emergency disconnect
system and light was on signifying that they had when in fact nothing happened
Automated system in BOP failed
44

45. Kick Test Monitoring
● Individuals sit in front of the alarms for 12 hours at a time
● Simultaneous activities and other monitoring responsibilities.
45

46. Decision Making (Cont.)
Decisions were made that valued money
over safety
Introduction Phenotype Genotype Conclusion 46
Drift Toward Failure

47. Decision Making (cont.)
BP incidents in the Gulf of
Mexico preceding the
Deepwater Horizon
accident
1996-2009
79 incidents
47

48. Organizational Culture
● 46% of the crew surveyed reported felt that some of the workforce feared
reprisals for reporting unsafe situations
Introduction Phenotype Genotype Conclusion
Pathological
Culture
48

49. Organizational Culture (cont.)
49
Breakdown at
Boundaries

50. Organizational Culture (cont.)
Insert Bob Bea quote about how it’s similar to NASA’s culture… faster, better, etc
Introduction Phenotype Genotype Conclusion 50

51. Organizational Culture (cont.)
BP was criticized for neglecting to “address human performance issues and
organizational factors which, in any major accident investigation, constitute
major contributing factors,” He added that BP’s investigation also ignored
factors such as fatigue, long shifts, and the company’s poor safety culture
- Najmedin Meshkati
Introduction Phenotype Genotype Conclusion
No Preoccupation
with Failure
51

52. Scheduling
As of April 20, BP and the Macondo well were almost six weeks behind schedule
Introduction Phenotype Genotype Conclusion 52

53. Budget
More than $58 million over budget
Introduction Phenotype Genotype Conclusion 53

54. Government Regulatory Failures
Introduction Phenotype Genotype Conclusion 54

55. Poor Communication
● Transocean experienced a near miss eerily similar to the Deepwater Horizon
incident four months prior in the North Sea
● Mud spewed onto the rig floor, but crew was able to seal the well before a
blowout occurred
● PowerPoint and advisory were created to require standard well control but
neither made it to Deepwater Horizon
● Had the rig crew known about this incident and had been trained, events at
Macondo could have turned out very differently
Introduction Phenotype Genotype Conclusion 55

56. Lack of communication between management and crew
Introduction Phenotype Genotype Conclusion 56

57. Swiss Cheese Model
Holes:
● Well casing
● Centralizers
● No further tests on foam cement
● Not completing “Bottoms Up” process
● Not completing cement bond log test
● Missed kick detection
● Blind shear ram failure due to pipe buckling
● Overlooking models
● Time pressures
57

58. Sequence of Events Model
58

59. Aftermath of the accident
● Spilled for 87 days
● Estimated 210,000,000 gallons of oil spilled
● Impacted 68,000 square miles of ocean
● More than 8,000 birds, sea turtles, and marine mammals found injured or
dead within 6 months after the spill
● 16,000 miles of coastline affected
● Cost BP up to $60 billion in legal and cleanup
● July 15, 2010 BP says oil spill has stopped
59

60. Effects on Environment
60

61. Effects on Surrounding Businesses
61

62. Resulting Costs
● Estimate of $32 billion to cover cleanup, legal costs, fines, and other costs
○ $14 billion to contain and clean up the spill
○ $5.4 billion to settle 60,800 claims to date with individuals and business affected by the spill
○ $4 billion for criminal penalties and fines, including payments to the National Fish and
Wildlife Foundation
○ $525 million to settle civil charges with the S.E.C that it misled investors about the flow rate
of oil from the well during the spill
○ $236 million to revitalize tourism in Gulf Coast states
62

63. Results of court proceedings?
•A federal grand jury returned an indictment charging the two highest-ranking BP
supervisors on board the Deepwater Horizon on the day of the explosion with 23
criminal counts
•The two men were charged with seaman’s manslaughter and involuntary
manslaughter for each of the 11 men killed
•Also charged of criminal violation of the clean water act
63

64. Legal changes
64

65. Recommendations
Just some ideas:
● Redundancy
● De-coupling
● New leadership
○ Organizational decision making
○ Stress safety!
● Simulation training
● Coordination between technical expertise and authority
○ Managers, contractors, and crew
65