deepwater horizon disaster - rice universitynagaraja/dhd_4.pdf · current state: june 15, 2010 the...

Deepwater Horizon DisasterProfessor Satish Nagarajaiah

Dept. of Civil & Env. Eng. , Dept. of Mechanical Eng. & Material Sc.Rice University, Houston, TX, USA

[email protected]

b D i S d G (D SG)Member, Deepwater Horizon Study Group (DHSG)Univ. of California, Berkeley

Dedicated To The Men and Women Who Serve Our CountryAnd To Those Who Lost Their Lives Doing Their Duty

Invited Lecture, ASCE Houston Chapter, June 15, 2010Disclaimer: This study is meant to be purely technical documentation of events and causes. It is not meant to place blame

on any individual or company or industry or government

Offshore and Marine Systems Research @ Rice

on any individual or company or industry or government.

Space Shuttle ColumbiaDisaster


Space Shuttle Columbia Disaster

Source: CAIB

Space Shuttle ColumbiaDisasterDisaster

Source: CAIB

Source: CAIB

World Trade Center, September 11, 2001


Chevron Typhoon TLP in 2000 ft of Water: 40,000 barrels/day and 60 million CFTof natural gas. Was upended by Hurricane Rita in 2005, but no leak!! and thingsworked fine. The platform turned into a natural reef.

BeforeBefore

After: The Platform and

Derrick Underwater


UnderwaterSource: Chevron

Shell Mars TLP in 3250 ft of Water: 220,000 barrels/day and 220 million CFT of natural gas. Badly damaged in Hurricane Katrina 2005. No leak!! and things worked fi Th M l f i b k i ifine. The Mars platform is back in operation.

Restored Platform and

Derrick

Damaged Platform and

Derrick


Source: Shell

OutlineDeepwater Horizon Disaster

April 20, 2010

Unfolding Environmental DisasterUnfolding Environmental Disaster

Impact of the Oil Spill

Oil Spill Response and Containment Measures

Ongoing Investigationsg g g

Concluding Remarks


Deepwater Horizon Rig


Source: MMS and BP

April 20, 2010At approximately 10 pm Horizon Rig disaster started

Initial explosion due to Gas/Oil/Mud surge and ignition upon entry into the engine room

Fire starts and power failure

Vi l t ib ti th t h k th ti iViolent vibrations that shook the entire rig reported

Second explosion

Rig evacuated and fire/containment response and


Rig evacuated and fire/containment response and rescue begins by nearby vessels

Horizon Rig April 20/21/22, 2010


Source: MMS/AP/flickr

Collapse / Oil Spill


Source: NYT/AP/flickr

Horizon Before/After Collapse

Horizon Drill Rig

Ocean Surface

21 “ RiserRiser

BOP Stack

Wellhead

5000 ft

18000 ft Reservoir


18000 ft Reservoir Source: Live Science

Containment Response (ROV - BOP Shr Ram)April 24 - several days


Source: MMS/BP

Containment Response (Riser Insertion Tube)May 15


Source: BP

Containment Response (Top Kill/Junk Shot)May 26/27


Source: BP

Containment Response (Riser Cut & LMRP Cap) May 29


Source: BP

Surface/Subsurface Containment Response


Source: BP

Containment Response (Largest Ever)


Source: BP

Containment Response (Largest Ever)


Source: MMS/BP/flickr

Containment Response (Relief Wells)Mid August


Source: BP

Environmental and Ecological ImpactSo

urce

: NYT

S

Environmental and Ecological Impactce

: NYT

Sour

c

Cementing Procedure


Figure Source: NYT

d W

ell

s Dril

led

AsM

MS/

DH

SGSo

urce

: M

esig

nW

ell D

eW

orto

nD

HSG

/Hal

ibo

Cement Seal Lacking

Sour

ce: D

Blow Out Preventer (BOP)Riser AdapterRiser Adapter

Flex Joint

Control Pod with Upper/Lower Annular

Ram BehindRa Behind

Kill Line

Riser Connector

Choke Line

Blind Shear RamCasing Shear Ram

Pipe RampPipe RamTest Ram


Stack Connector

U.S. House of Representative—Energy and Commerce Committee Investigation (http://energycommerce.house.gov/index.php?id=22)

“Th C itt ' i ti ti i i i i ti b t th d i i

Excerpts from the Letter dated June 14, 2010, from Senate Energy and Commerce Committee toMr. Tony Hayward, CEO, BP

g ( p gy g p p )

“The Committee's investigation is raising serious questions about the decisionsmade by BP in the days and hours before the explosion on the DeepwaterHorizon.

On April 15, five days before the explosion, BP's drilling engineer called Macondoa "nightmare well." In spite of the well's difficulties, BP appears to have mademultiple decisions for economic reasons that increased the danger of acatastrophic well failurecatastrophic well failure.

In several instances, these decisions appear to violate industry guidelines andwere made despite warnings from BP's own personnel and its contractors.

In effect, it appears that BP repeatedly chose risky procedures in order to reducecosts and save time and made minimal efforts to contain the added risk.”


Source: U.S. House of Representatives - Energy & Commerce Committee

U.S. House of Representative—Energy and Commerce Committee Investigation (http://energycommerce.house.gov/index.php?id=22)

“At the time of the blowout, the Macondo well was significantly

g ( p gy g p p )Excerpts from the Letter dated June 14, 2010, from Senate Energy and Commerce Committee toMr. Tony Hayward, CEO, BP

behind schedule. This appears to have created pressure to take shortcuts to speed finishing the well. In particular, the Committee is focusing on five crucial decisions made by BP: (I) h d i i ll d i i h f b i fl(I) the decision to use a well design with few barriers to gas flow; (2) the failure to use a sufficient number of "centralizers" to prevent

channeling during the cement process; (3) th f il t t b d l t l t th(3) the failure to run a cement bond log to evaluate the

effectiveness of the cement job; (4) the failure to circulate potentially gas-bearing drilling muds out of

th ll dthe well; and (5) the failure to secure the wellhead with a lockdown sleeve before

allowing pressure on the seal from below. The common feature of these five decisions is that they posed a trade off between


of these five decisions is that they posed a trade-off between cost and well safety.”Source: U.S. House of Representatives - Energy & Commerce Committee

BP Internal Investigation“BP investigation team’s work thus far shows that this accident was brought about by the failure of a number of processes, systems and equipment. There were multiple control mechanisms— procedures and equipment—in place that should have prevented this accident or reduced the impact of the spill: the investigationhave prevented this accident or reduced the impact of the spill: the investigation is focused on the following seven mechanisms.

1. The cement that seals the reservoir from the well;1. The cement that seals the reservoir from the well;2. The casing system, which seals the well bore;3. The pressure tests to confirm the well is sealed;4. The execution of procedures to detect and control hydrocarbons in the well,4. The execution of procedures to detect and control hydrocarbons in the well,including the use of the BOP;5. The BOP Emergency Disconnect System, which can be activated by pushing a button at multiple locations on the rig;p g p g6. The automatic closure of the BOP after its connection is lost with the rig; and7. Features in the BOP to allow Remotely Operated Vehicles (ROV) to close


the BOP and thereby seal the well at the seabed after a blow out.” Source: BP

BP Internal Investigation“Before, during or after the cement job, an undetected influx of hydrocarbons entered the wellbore”“The 9 7/8” casing was tested; the 9 7/8” casing hanger packoff was set and g ; g g ptested, and the entire system was tested”“After 16.5 hours waiting on cement, a test was performed on the wellbore below the Blow Preventer (BOP)”“During this test, 1400 psi was observed on the drill pipe while 0 psi was observed on the kill and the choke lines”“Following the test, hydrocarbons were unknowingly circulated to surface while displacing the riser with seawater”while displacing the riser with seawater“As hydrocarbons rose to the surface, they expanded, further reducing the hydrostatic pressure. The well flowed and witness account suggest that the Annular Preventer in the BOP and the Diverter were activated”Annular Preventer in the BOP and the Diverter were activated“An explosion occurred, followed by a power failure”“Witness accounts suggest that the Emergency Disconnect System was activated”


Source: BP/U.S. House Energy and Commerce Committee

BP Internal Investigation

“The rig was evacuated”“The BOP system failed to work as intended. Flow was not contained and theThe BOP system failed to work as intended. Flow was not contained and the Lower Marin Riser Package did no disconnect”“Modifications have been discovered in the BOP system”“Leaks have been discovered in the BOP hydraulics system”y y“BP launched an investigation which is ongoing”

INVESTIGATION THEMES

“Cementing – design and execution”“Casing – design and installation”g g“Casing Hanger – Design and Installation”“BOP – Configuration, maintenance and Operation”


Source: BP/U.S. House Energy and Commerce Committee

Current State: June 15, 2010The updated flow group spill estimate is 35,000 to 60,000 barrels/day. The flow has doubled due to two reasons: (1) "T kill" ti b ti t th h k d kill li th bl(1) "Top kill" operation—by connecting to the choke and kill lines on the blow out preventer (BOP) and pumping 30,000 barrels of mud into the well—has increased discharge. It appears that instead of clogging the pipe (remember Junk Shot was supposed to bridge the BOP) the top kill operation has made pp g ) p pthe discharge much more rapid (i.e., cleared the pipe of all obstruction including whatever cement plug was holding; the exact opposite of what it was supposed to do). (2) Th i t h i d th fl d ti ll th ki k h(2) The riser cut has increased the flow dramatically—the kink was much more severe than originally estimated. In this I must say that I was taken in by the response team's estimate of 20%. Obviously I wish I had access to the kink photographs to examine more closely. Unfortunately there are no good p g p y y gphotographs of the kink. Only the response team and flow measurement team has access to this information. In essence the flow has doubled from before due to the aforementioned reasons.


Current State: June 15, 2010The flow measurement team has more accurate sensor data based on pressure and flow sensors that BP has installed at the leak point. They estimate the flow to have doubled from their previous estimates of 25 000 toestimate the flow to have doubled from their previous estimates of 25,000 to 30,000 barrels/day. So here is the updated version of my current estimate 23,000* x2.0 = 46,000 barrels/day—which turns out to be nearly the average of (35,000 + 60,000)/2 = 47,500 barrels/day. Hopefully BP can start capturing

h th 15 000 b l /d M BP t thmuch more than 15,000 barrels/day. More BP assets are on the way (unfortunately ships take time to cross the high seas) and should help in capturing significantly more leaking oil/gas. An important point to remember is that BP will capture a mixture of oil/gas and sea water. So when BP says they p g y ywill be able to capture 80,000 barrels/day it means they will get most, but not all. So relief well is the only permanent solution.

* My earlier estimates from May 20, 2010 put the leak at 23,000 barrels/day (visit www.ruf.rice.edu/~nagaraja/DHD.htm


Concluding Remarks

Worst Environmental and Ecological Disaster Ever in the United States

August – September by the time this is all over and recovery begins

White House Panel to Investigate the Deepwater Horizon Disasterg p

Deepwater Horizon Study Group to conduct its own investigation

MMS and regulatory structure expected to undergo significant changes

More stringent safety and redundancy requirements likelyg y y q y

The oil industry will weather this storm, but come out significantly safer but changed for good


deepwater horizon disaster - rice universitynagaraja/dhd_4.pdf · current state: june 15, 2010 the...

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