Deepwater Horizon Blowout

• Deepwater Horizon was drilling an exploratory well in the Macondo prospect in the Gulf of Mexico
• The rig experienced a blowout, leading to an explosion and oil spills

The Rig

• It was a top-performing rig in safety
• The rig was SEMISUBMERSIBLE, meaning it floats on the surface
• It had buoyant pontoons submerged below the water's surface to reduce the impact of waves and wind
• It had thrusters, controlled via satellite signals, to remain stable and accurately positioned during drilling

What Happened?

• Pressure tests were misinterpreted, specifically the negative pressure test
• The crew believed the well was secure, but it failed to detect a gas influx from the reservoir
• The crew prepared to remove the drilling mud, and gas pressure overcame the mud's weight
• This led to a blowout, where gas and oil surged up the well, causing the explosion and fire

Initial Response

• The rig sank but remained attached to the well via the connecting pipe
• As the rig sank, the pipe broke, leaving sections attached to the rig and protruding from the well
• ROVs assessed the situation and revealed two leaks, and finding solutions proved challenging

Kill the Well Options

• How to stop the flow?
• The Dome - to cover the wellhead and capture leaking oil
• Nuclear weapons were ruled out by the US
• Method to stop the flow of oil and gas from the well
• Involves pumping heavy drilling mud into the well to push oil and gas down
• Additional material is added to increase pressure
• A concrete cap is sealed on top to keep everything contained

Capping Stack

• Used in oil and gas industry when there is an uncontrolled release of oil or gas
• It is installed on top of the existing BOP stack and used to contain the leak
• Features valves and other mechanisms to control the flow of fluids from the well

Earth Day

• The Bankston boat rescued crew members
• On April 22, 2010, the rig sank, killing 11 people and seriously injuring 16

Clean Up Using Skimmer, Boom, In Situ Burning, Dispersants

• MSRC responded to spill using 4 methods
• Skimmer - Physically recovers oil on water's surface, and efficiency depends on ocean conditions
• MSRC deployed 4 skimmers immediately to recover 500,000 barrels/day
• Most Common - Weir Shimmers
• Booms - Large floating, physical barriers slow and contain oil spread
• 3 main types: hard, sorbent, fire

In Situ Burning

• Process of burning spilled oil on the ocean surface
• Requires a fire boom to contain the process in a specific area, and a layer of material is needed to maintain the process
• Then igniting the oil to reduce its volume and toxicity
• Air was monitored for safety, and there was aerial monitoring via aircraft, drones, and helicopters

Dispersants

• Surfactants that break down oil into smaller droplets and allows oil to disperse into the water column
• Does not remove oil, but is believed to make biodegradation easier

Deep Sea Dispersants

• First time dispersants were used in the deep sea so ROVs targeted the oil spill to prevent surface problems and this was beneficial

Dirty Blizzard

• Process where dispersants, microbes, and mucus combine with oil and gas to create marine snow that sinks to the sea floor

Pros and Cons of Dispersants

• Pros: less oil reaches the shoreline; fewer surface animal encounters; accelerate biodegradation; can use in bad weather
• Cons: more oil in the water column; more exposure to marine life in water; not sure if it would work

Human Impacts

• Thousands volunteered to help clean up
• Workers exposed to toxic hazards
• Bodies were under serious pressure due to physical exertion
• The conditions and the weather
• Human impacts were studied less, very little baseline data

Animal Impacts

• Exposure involves ingestion, filtration, inhalation, absorption, and bioaccumulation
• Collection numbers: 8,183 birds, 1,144 sea turtles, and 109 marine mammals

Birds

• 93 species exposed
• Exposure impacts: mobility and red blood cells
• Cleaned with dawn dish soap
• Food web impacted
• Estimated loss of 80,000 - 1 million birds

Fish

• Injuries may include: unusual lesions, rotting fins, and oil in the liver
• Toxic to larval fish (2-5 million deaths)
• USF Research: all fish impacted
• Traces of oil in lipid storage

Dolphins & Whales

• 1400 marine mammals in slick
• Increased mortality & reproductive failure
• Barataria Bay and Mississippi Sound species were greatly impacted population wise

Sea Turtles

• 5 species impacted with restricted movement and ingestion
• 275 nest relocated, mortality estimates: 7600 adults and 166,000 hatchlings

Gulf Floor

• Three deep-sea coral species were damaged
• Two shallow, long time to recover

Oyster Reefs

• Filter feeders damaged so couldn't filter
• 8.3 billion dead, impairing sustainability effort

Environmental Impacts

• Epidemic: missing data on GOM conditions and organisms
• Currents and winds kept oil away from land and oil-eating microbes broke down crude oil
• Warm temperatures broke down oil

Area & Habitat Impacts

• Organisms:
  • Deep sea: squid, coral
  • Water column: plankton, jellyfish
  • Air: seabirds
• Environments:
  • Salt marshes, mudflats
  • Mangroves, sandy beaches
• 650 miles of habitat, 130 miles in heavy oil
• Salt Marshes - Root damage, boom damage
• Mudflats - Super sensitive, bioturbation which is organisms burrowing and mixing everything
• Sandy Beaches - Erosion, wrack zone

Restoration Efforts

• $18.8 billion was paid by BP for restoration

Louisiana Approach

• Resource-specific restoration
• Ecosystem-level injuries
  • Wetlands, coastal, & nearshore
  • Water quality & habitat
  • Replenish and protect wildlife and marine resources
• 70+ projects still happening

Human Effects

• Psychological effects: stress, anxiety, depression
• Physical health effects: headaches, fatigue, vomiting
• Economic effects: jobs lost, increased costs, property damage
• Sociological effects: population displacement, social disruption, social conflict
• Cultural effects: loss of identity, loss of security

Health Effects

• Workers experienced nonfatal & fatal heart disease, and reduced lung function
• Public health concerns: respiratory, gastrointestinal effects, depression, anxiety
• Moratorium on fisheries which reduced exposure probability
• 10,000 samples were tested for oil