oil spill program black rev3 06 29-2010 md_klein

The BP Oil Release in the Gulf of Mexico: Ocean Engineering,Gulf Currents & HAZMAT Issues

Michael Klein, P.E., CHMMJune 29, 2010

What Happened?

• On 20 April 2010 eleven workers died in an explosion on the BP-contracted Deepwater Horizon oil drilling rig located in the Gulf of Mexico

• A surge in oil and gas caused the explosion on the Deepwater Horizon.

• The Blowout Preventer (BOP), a system of valves at the well head located at a depth of 5067 feet

• The BOP is believed to have failed.

The BP Oil Release in the Gulf of Mexico: Ocean Engineering, Gulf Currents & HAZMAT Issues

What Happened?

• On 22 April 2010 the oil rig sinks and the riser pipe connected it to the well falls to the sea bed.

• Crude oil and gas continue to flow from the bent riser pipe and BOP resulting in an oil slick that is estimated at 5 miles in diameter.

• The BOP is designed to be the fail safe against pressure surges. Its valves should have closed shutting off the oil and gas from the reservoir and sealing the well.


The Blowout Preventer


Source :New York Times

What Should Happen in an Emergency

• In a blowout, a rig worker presses an emergency button. A signal is sent from the rig down an electrical line to one of the control pods.

• The control pod directs hydraulic fluid from the rig and from a bank of pressurized canisters, called accumulators.

• Hydraulic fluid flows rapidly through a valve, called a shuttle valve, and into the blind shear ram.

• The blind shear ram cuts through the drill pipe and seals the well, preventing oil from gushing out.



• Of all the components on the blowout preventer, only the blind shear ram was designed to shut down the well in a blowout like the one that took place on the Deepwater Horizon oil rig on 20 April 2010.

• It is the only device on the BOP that is supposed to cut through the thick drill pipe and seal off the hole.



• Pistons push the ram toward the pipe.• Offset blades on the ram cut the pipe.• The pipe breaks and collapses.


Source: New York Times


• Unlike other parts of the Deepwater Horizon’s BOP, the blind shear ram has no backup.

• The breakdown of any part of the hydraulically powered ram can lead to disaster.

• One of the most critical components of the blind shear ram is the shuttle valve, the only point for the hydraulic fluid to enter the ram.



• A risk analysis commissioned by the manufacturer of the blowout preventer identified this shuttle valve as one of the weakest links.

• So if the shuttle valve fails, the well will not be sealed.


BP Oil Release Responses

• The failure of the BOP and the efforts made to remotely shut it down result in a constant leak of oil and gas from holes in the bent riser pipe resting on the seafloor and above the BOP.

• Efforts are made on the surface to contain the oil using techniques such as booms to contain the oil and skimming to recover it.

• Burning of the surface oil and dispersants are employed on the released crude oil.



• On the 2nd and 16th of May 2010 BP starts drilling relief wells.

• The plan is connect with the original well and pump heavy material in to stop the flow of oil and seal the well.

• The time to complete the operation is anticipated to be 2 to 3 months to complete

• 5 May 2010 BP caps the end of the drilling pipe stopping one of the three leaks



• 5 May 2010 BP attempts to stop the main leak by lowering a containment dome over the site.

• This fails on 8 May 2010 as the dome extraction piping is blocked by frozen hydrate crystals.

• The hydrate crystals are caused by the leaking gas in the crude oil.

• 16 May 2010 a tube is inserted into the leaking pipe to funnel off leaking gas and crude oil to a surface ship


BP Oil Release Responses• 26 May 2010 BP starts the “Top Kill”.


BP Oil Release Responses• A “junk shot” is injected in an effort to

block the flow of crude oil.• 29 May 2010 BP announces that the top

kill system has failed and the oil spill continues.

• 2 June 2010 BP starts the next shut down procedure.– Remotely operated shears are used to cut the

damaged riser pipe.– A wire cutter was used in an attempt to saw

through the leaking pipe close to the top section of the BOP.

– The blade gets stuck and the pipe is then cut by remotely operated shears


BP Oil Release Responses• View of an underwater robotic arm

attempting to free the diamond saw that became stuck.

Source: BP Live Video Feed



• 4 June 2010 a “Cap” is placed over the upper portion of the leaking well funneling oil and gas to a surface ship.

Source: New York Times / BP



• Crude oil continues to billow from under the lip and through four open vents on top of the device.

• Methanol is being pumped into the cap to prevent the formation of icy hydrates that could block the mile-long pipe rising from the cap.

• Engineers hope to capture more oil by progressively closing the cap vents.



• 16 June 2010 using equipment originally put in place to inject heavy drilling mud during the failed “top kill” the modified system extracts oil and gas directly from the blowout preventer, – The captured crude oil passes through a

manifold on the seafloor and pipes it up to the Q4000 surface vessel.

– The Q4000 has no storage capacity and burns the oil and gas.



Source: New York Times / BP

BP Oil Release Responses• 22 June 2010 BP collects a total of 27,090

barrels– BP flare 10,425 barrels of oil– Captures 16,665 barrels of oil. – flared 54.4 million cubic feet of natural gas.

• As of 22 June 2010 BP has recovered 325,700 barrels of oil since it put in place a containment cap and the flaring system.

• At full optimization, the current operation could capture up to 28,000 barrels a day



• The operation involves two ships, the Discoverer Enterprise, which has the capacity to collect and store about 18,000 barrels of oil a day, and the Q4000, which can burn off about 10,000 barrels of oil a day.

• The release rate is estimated at 35,000 to 60,000 barrels of oil a day.


Gulf of Mexico: Geography

• The Gulf of Mexico is a dynamic, almost landlocked body of water dominated by prevailing southeast winds and influenced by the Gulf Loop Current and Mississippi River flow.– Bordered on the east by the Florida peninsula,

to the north by Alabama, Mississippi and Louisiana.

– To the west by Texas, Mexico and the Yucatan peninsula.


Gulf of Mexico: Geography

– Bordered and nearly landlocked by North America and Mexico

– Connects to Atlantic Ocean via Florida straits north of Cuba

– Connects with Caribbean Sea via Yucatan Channel between Mexico and Cuba


– Area of 615,000 sq. miles

– Sigsbee Deep at 12480 feet, the deepest point

– Site of 65 million year old Chicxulub crater


Gulf of Mexico: Currents and Prevailing Winds

Source: University of Texas at Austin Marine Science Institute


• Prevailing winds blowing from the southeast move Caribbean water through the pass between Yucatan and western Cuba, forming the Gulf Loop Current.

• This current moves north towards the Mississippi and Alabama coast lines then curves south along the west coast of Florida and exits the Gulf between the Florida Keys and the north shore of Cuba.



• The Gulf Loop current joins the Antilles current, forming the Gulf Stream.

• The Gulf Stream travels north up the east coast of the United States then curves east towards Europe. – It carries warm, tropical water north.

• This is one of the reasons that commercial fisheries off the Grand Banks in New England are so productive.


Gulf Currents and Oil Spill Interaction

• Current data indicates that the spreading oil slick has grown in size and is connected with the Loop Current that sweeps around the Gulf.

• The "entrainment” (oil is incorporating into the Gulf Current) is pulling the released crude oil quickly south along Florida's Gulf coast and out into the Florida Straits, between the United States and Cuba.



• Should the oil slick enter the Florida Loop Current ocean circulation models show it heading out to sea, past the Dry Tortugas islands, before it is caught up in the Gulf Stream and makes its way up the U.S. East Coast. – Whether or not the oil spill will get into shallow

water on its possible ocean journey would be totally dependent on winds



• Depending on local winds, Florida's southwest beaches and the Florida Keys, along with coral reefs and the fragile ecosystem of the Everglades, could be spared from the oil slick.

• The oil making landfall anywhere will depend on what the winds are doing at that particular point in time.


Hazmat Considerations of Crude Oil

• Crude Oil (CAS number 8002-05-9): Crude oils vary in physical characteristics such as color, viscosity and specific gravity.

• Color ranges from light yellow-brown to black.

• Viscosity varies from free-flowing to a substance that will barely pour.

• Specific gravity is used to classify crude oil as light, medium (intermediate), or heavy.

• Crude oil, which may consist of hundreds of individual compounds must be refined to separate the constituent into useful fractions.

• Each crude oil is a unique mixture, not matched exactly in composition or properties by any other sample of crude oil.


Hazmat Considerations of Crude Oil

• Individual compounds of crude oil can be classified into the following two categories:– Hydrocarbons, which include alkanes (normal

and branched chains), cycloalkanes, alkenes, aromatics, naphthenoaromatics; and

– Non-hydrocarbons, which include nitrogen, sulfur and oxygen (NSO) compounds, asphaltenes and resins (including NSO heterocyclics), metallo-organics, and inorganic metal salts.


General Hazard/Toxicity Summary

• In general, spilled oil is most harmful when shallow, productive waters; porous sediments; low energy aquatic environments or special-use habitats are affected.

• Examples of high risk locations are – Wetlands– Sheltered tidal flats– Shallow bays– Coarse sand and gravel beaches– Sites with concentrated reproductive and

migratory activities


Evidence of Underwater Oil

• University of South Florida researchers have confirmed layers of petroleum hydrocarbons stretching at least 50 miles from the leaking well in the Gulf of Mexico

• The plumes contain tiny droplets of oil — from the size of a thumbnail to the size of a golf ball.

• Underwater oil created in part by the effect of chemical dispersants.


Evidence of Underwater Oil

• Plumes would have a unique role in devastating marine life.

• The low levels of dissolved oxygen in and around the plumes could literally choke fish and other life.

• Dissolved oil could also accumulate in fish larvae and filter feeding creatures — which would then pass the toxin up the food chain to fish that include commercially important species like red snapper.


Petroleum Impact: Fish

• Crude oil and petroleum products vary considerably in their toxicity, and the sensitivity of fish to petroleum varies according to species.

• The water soluble fractions of crude oil can stunt fish growth.

• The impacts to fish are primarily to the eggs, larvae, and early juveniles, with limited effects on the adults.


Petroleum Impact: Fish

• The general effects of petroleum are difficult to assess and quantitatively document due to the seasonal and natural variability of the species.

• Fish rapidly metabolize aromatic hydrocarbons due to their enzyme system.


Potential Effects of Petroleum: Fish

• There are several potential effects of petroleum on the fish– depressed feeding.– decreased swimming activity and increased mortality

(observed effect). – mortality to eggs and larvae. – mortality or other effects of fish maintained in

mariculture enclosures

• Finally, there are several sublethal effects such as fin erosion, ulceration of the integument, liver damage, lesions in the olfactory tissue, reduced hatching success, reduced growth, change in egg buoyancy, malformations that interfere with feeding, arrest of cell division, and genetic damage.


Potential Effects of Petroleum: Fishing Industry

• Potential effects include:– exclusion of fishermen from the fishing grounds

and other disruption of fishing which can change the population balance to date.

– tainting of fish (such as change in flavor or smell) and the public's fear of tainting, mortality or other effects of non-motile inshore species.

– loss of livelihood not only for fishermen but for other industries supported by this commodity.


Petroleum Impact: Birds

• Oiling of feathers is considered to be the primary cause of most bird deaths following oil spills– Oil disrupts the fine strand structure of the

feathers resulting in• loss of water repellency and

• in decreased body insulation


Getty Images


• Natural response to oil matted plumage is preening; – oiled birds often ingest petroleum while

attempting to remove the petroleum from their feathers.

• Chicks may be exposed to petroleum by ingesting food regurgitated by impacted adults.



• The effects of ingested petroleum include:• Anemia• Pneumonia• Kidney and liver damage• Decreased growth• Altered blood chemistry• Decreased egg production and viability

• This is migration, spawning and nesting time for migratory song birds and the endangered brown pelican

• Upwards of 25 million birds a day transit the Gulf region in their northern migration.


Petroleum Impact: Birds• More than 70 percent of the country’s

waterfowl frequent the gulf’s waters, including the Brown Pelican, Least Tern, and the Piping Plover.

• For the brown pelican it is nesting season and one of it principal rookeries is in the Breton National Wildlife Refuge Louisiana, which the release crude oil has impacted.


Getty Images

Toxicity of Crude Oil

• The toxicity of crude oil can be interpreted as the toxicity of a complex mixture of inorganic and organic chemicals.

• Uncertainty exists in the use of dose-response relationships based on crude oil as a whole mixture.

• An alternative approach which is often used is the "indicator chemical approach."– This involves selecting a subset of chemicals

from the whole mixture that represents the "worst-case" in terms of mobility and toxicity.


Indicator Chemical Approach

• This approach can be used with crude oil with the subsets of chemicals being:– Volatile organics such as benzene, toluene,

ethylbenzene, and xylenes (known as BTEX; if present)

– Polynuclear Aromatic Hydrocarbons (PAHs).

• BTEX are of interest because they are soluble in water, highly mobile in the environment, and represent the more volatile and soluble components of crude oil.



• Benzene is an EPA defined “Class A” carcinogen. – “Class A” carcinogens as pollutants with

adequate human data indicating the chemical causes cancer in people

• PAHs are not highly mobile but are of interest because they are prevalent in crude oil, represent the heavier or less volatile crude oil components, and several are known animal carcinogens.



• PAHs and their transformation products are among the most hazardous constituents of crude oil.

• Crude oil contains, on the average, approximately 1% polynuclear aromatic hydrocarbons (PAHs).

• Concentrations of total carcinogenic PAHs (like benzo(a)pyrene) reported in the literature range from 12 mg/l to less than 100 ug/l.


Oil Weathering Process

• After oil is discharged into the environment, a wide variety of physical, chemical and biological processes begin to transform the discharged oil.

• Collectively, these processes are referred to as weathering, and act to change the composition, behavior, routes of exposure and toxicity of the discharged oil.



• Weathered oil is composed of relatively insoluble compounds, and often coalesces into mats or tarballs.

• As a result, the potential for exposure to fish through water column toxicity is lessened, as is the potential for birds or mammals to encounter the oil.

• For example, penetration of oil into marsh vegetation may depend on oil viscosity; weathered oils penetrate less than fresh oil.



• Alternatively, certain species are known to ingest tarballs and the potential for exposure to those resources may increase as the oil weathers.

• The loss of the lighter fractions through dissolution and/or evaporation during the weathering process can cause normally buoyant oil to sink.– Thereby contaminating subtidal sediment and

contributing to water column toxicity.



• After the loss of the volatile, soluble, and easily biodegraded compounds, the remaining compounds can become concentrated.

• Weathered oil becomes less acutely toxic, but due to polynuclear aromatic hydrocarbons (PAHs) of high molecular weight, it remains toxic.



• The primary weathering processes are physical phenomena; these include: – Spreading– Evaporation– Dissolution– Dispersion– Emulsification– Sedimentation



• Chemical weathering processes include photo degradation and oxidation.

• Biological weathering processes include (microbial) biodegradation and ingestion and depuration by organisms.



• These processes occur for all discharges, but the rate and relative importance of each process depends on– spill characteristics, – environmental conditions, and– physicochemical properties of the spilled

material.


Hazmat Response to a Release of Crude Oil

• Most crude oil is defined as Medium Oils per the NOAA/Hazardous Materials Response and Assessment Division (HMRAD) Shoreline Countermeasures Manual for tropical coastal environments. – About 1/3 will evaporate within 24 hours.

– Maximum water-soluble fraction is 10-100 mg/l.

– Oil contamination of intertidal areas can be severe/long term.

– Impact to waterfowl and fur-bearing mammals can be severe.

– Chemical dispersion is an option within 1-2 days.

– Cleanup most effective if conducted quickly.


Response to an Oil Spill On Water: Boom

• Boom technology comes in many sizes, shapes, and types and is used primarily to deflect and/or collect oil.


Getty Images

Response to an Oil Spill On Water: Burning

• Fresh oil contains gases which are very volatile. By igniting these gases whole oil slicks can be reduced to tarry residue.

• Many factors effect whether or not a burn can occur and if it will be successful.

• Burning is highly dependent on the amount of time the oil has been on the water because when a burn is conducted fumes from the oil are ignited, not the actual oil.

• As oil weathers on the water, these fumes dissipate and eventually are insufficient to start combustion.


Response to an Oil Spill On Water: Dispersants

• Dispersants work much like the detergent soap that you use to clean grease from your dishes (but dispersants are less toxic).

• They contain molecules with a water-compatible ("hydrophilic") end and an oil-compatible ("lipophilic") end.

• These molecules attach to the oil, reducing the interfacial tension between oil and water, breaking up the oil slick, as shown on the following slide.


Response to an Oil Spill On Water: Dispersants


Source: ITOPF

Response to an Oil Spill On Water: Skimming

• Skimming is a mechanical system for removing oil from the surface. This process was created based on the reality that oil is lighter than water.


Getty Images

Response to an Oil Spill On Water: On the Beach

• Bioremediation– Utilizes beneficial microbes, surfactants,

micronutrients and bio-stimulants to stimulate the growth of "oil-eating" microbes.

– The process is adopted where excavation is impractical and involves either bio-stimulation or bio-augmentation.


Getty Images


• Biostimulation involves aeration and the application of selected micronutrients and bio-stimulants.

• Bio-stimulation is only effective when indigenous microbial populations, present in the substrate, are high enough to degrade the contaminants and when these microbes can readily adapt to foreign contaminants.

• Bioaugmentation involves the application of beneficial microbes, that have an affinity towards a specific contaminant.

• Stimulation of indigenous organisms by the addition of nutrients is the approach that has been tested most rigorously.



• Chemical Cleaning – In an attempt to avoid Hot Water & High

Pressure treatment, chemical cleaners have been tested which removed the oil from the beach for collection.

• Hot Water and High Pressure – By using hot water at high pressure, cleanup

crews blast oil off beaches into the water where it can be skimmed off.


Response to an Oil Spill On Water:On the Beach

• This method usually does more harm than good by driving the oil deeper into the beach and by killing every living thing on the beach.

• This was used extensively after the Exxon Valdez spill due to public and state pressure to make the beaches "look clean again," despite the known risks.

• Areas left alone to be weathered by winter storms were shown to be cleaner and harboring more life than those cleaned by high-pressure washing.


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• Manual Treatment– Manual treatment incorporates the use of

shovels, rakes, absorbent materials and human hands.


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• Mechanical Treatment– Tractors, backhoes, front-end loaders, and

other machines are used to move beach and scoop up asphalt collections for disposal.


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oil spill program black rev3 06 29-2010 md_klein

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