Oceans and Oil Spills

History of the Gulf Oil Spill• Explosion kills 11 men on rig on April 22,

2010• The Entire rig sinks on April 23, 2010• A customized containment cap was fitted to

the well in early June, – Oil was piped to the Discover Enterprise

vessel. • A second containment system was installed

in mid-June, using a manifold and hoses to carry oil and gas to the Q4000 vessel on the surface.

• On July 12, a new sealing cap was installed • On July 15, a well integrity test began in

which the cap’s three ram capping stack was closed, effectively shutting in the well and all sub-sea containment systems.

• On August 5, BP completed cementing operations at the MC252 well, as part of the static kill procedure.

• The relief well drilled by the DDIII drilling rig intercepted the annulus of the MC252 well on September 15

• Pumping of cement into the annulus on September 17, permanently sealed the well.

This Spill in Context (6 largest previous Spills)

June 3, 1979, 4.2- 12.5 million gal

November 1, 1979, ~2.6 million gal spilled, 7.8 million galburned

June 8, 1990, 5.1 million gal.

July 30, 1984, 2.7 million gal

August 10, 1993, 336,000 gal

August 8, 2005, >8 million gal in 250 reported spills

Active Oil Platforms in Gulf

Oil Pollution in our Oceans• 3.25 million metric tons of

petroleum annually• Human Sources

– Leaks at marine terminals– Disposal of drilling muds

from offshore operations– Municipal and industrial

wastes– Urban runoff into rivers– Atmospheric fallout from

the incomplete combustion of oil in motor vehicles

Exxon Valdez Oil Spill• Exxon Valdez

– 11.6 million Gal Spilled

• Horizon Spill– 210,000–4,200,000

gal/day

How Much Oil was spilled?

• Used optical plume velocimetry to estimate the velocity of fluids escaping the damaged well,

• Average flow rate from 22 April to 3 June– 5.6 x 104 ±21% barrels/day

• After the riser was removed– 6.8 x 104 ±19% barrels/day

• Taking into account the oil collected at the seafloor– 4.4 x 106 ±20% barrels of oil was

released into the ocean– ~1.8 billion gal.

• Crone, TJ & Tolstoy, M, 2010 Science

What happens in typical oil spill?

Mousse

Clean-up process• Use Dispersants• Collect with boom and

scoop out of ocean• Burn it

Gulf Oil Spill• Escaping oil sprayed

with dispersant at well head– Produced tiny droplets

of oil in deep ocean• Surface oil

– Collected with booms– Burned

The “Loop Current”• Initial concerns that

the surface oil would enter the loop current

• Winds helped to contain the oil

Gulf Stream from Satellite

Hurricane Impacts on Oil Spill• Hurricanes are likely to

disperse remaining oil further

• Potentially oil can be driven onshore through the storm surge

• BP States that deep water oil is in ppm and should not be significant

Hurricane effects on oil spill• Position and

approach of hurricane will effect potential damage

• Right side of hurricane can bring significant oil ashore

Gulf Oil Spill Clean-up• Escaping oil sprayed

with dispersant at well head– Produced tiny droplets

of oil in deep ocean• Surface oil

– Collected with booms– Burned

Shore Clean-up Methods• Can Spray water on

shore– Drives oil into

sediment– Hot water kills micro-

organisms

Meiofauna in Beach Environments

• Microscopic invertebrates that live in beach sands

• Base of the food chain

Meiofauna

Pelagic Organisms• Nekton may be able

to avoid oily areas• Plankton are unable

to move away

– Plankton-floaters– Nekton-swimmers

Benthic Organisms• Organisms that live

on the ocean bottom• Typically in shallow

water– 2 types

• Sessile-Cannot move to avoid oil

• Vagile-may be able to crawl or swim short distances to escape oil residue

Turtle Strandings on Gulf Coast

• Green is confirmed• Red are new

strandings• Too soon to tell

how many are from oil

• Numbers may be inflated

Sea Turtles Collected since Spill

Dead (5% oiled) Live (85% oiled)

OiledNo Oil

OiledNo Oil

Sea Turtles Collected by State

Florida Alabama Mississippi Louisiana Texas On Water0

50

100

150

200

250

300

350

400

450

500

LiveDead

Marine Mammal Strandings

Mammals Collected

Dead (4% Oiled) Live (22% Oiled)

OiledNo Oil

OiledNo Oil

Mammals Collected Since Oil Spill

Florida Alabama Mississippi Louisiana Texas On Water0

10

20

30

40

50

60

70

LiveDead

Volunteer Groups Capture Oiled Birds

• Brown pelicans are particularly susceptible

• Dive into water • Feathers become coated

with sticky mousse• Too heavy to fly• May die of

– exposure– starvation– drowning– exhaustion Gulf Coast oiled bird

Birds Collected since Spill

Dead (37% oiled)

OiledNo Oil

Live

OiledNo Oil

Note: Only live birds that were in distress were collected.

Number of Birds Collected

Florida Alabama Mississippi Louisiana Texas On Water0

500

1000

1500

2000

2500

3000

3500

LiveDead

Fishing Closures

October 5, 2010 October 22, 2010

Oil in the Water Column• Dispersant caused oil

to remain at depth• Natural bacteria eats

oil• Oxygen is depleted at

depth

Normal Oxygen Levels in the Ocean

BP’s Response• Amount Spent

– Over $8 billion spent to date– $20 billion claims escrow

fund– $100 million unemployed rig

workers' fund– $500 million establishing Gulf

Coast Research Initiative• Containment

– 827,926 barrels of oily liquid skimmed

– 265,450 barrels in controlled surface burns