Chapter #8 Flashcards
Crude Oil
Fossil Fuel, Non-renewable, extracted from deep well either on land or seafloor
Light Crude oil, Paraffin wax content is….
Low paraffin wax content
Heavy crude oil
higher density, high paraffin wax content, flow rate is slow
Sweet crude oil
low sulfur content
Canada has the ______largest oil reserves in the world and is
the ________ largest producer and fourth largest exporter of oil in the
world
third largest reserves, fourth largest producer
Petroleum and Natural gas formation
Plants and animals the died millions of years ago, where exposed to heat and pressure for a very long time turning them into oil and natural gas.
Where do we find oil? (Not the place but the area everytime)
In pore spaces between the grains of rock, either sand grains(quartz) or carbonites(limestone)
What is oil and gas in terms of chemistry the short name
Hydrocarbons
Porosity
The percent of space that is not occupied by solid rock grains
permeability of the rock tells us
how fast the oil and gas can flow through the rock
A fault trap occurs
when the formations on either side of the fault move.
Anticline
is an upward fold in the layers of rock, much like a domed arch in a building.
Anticlinal Traps
The oil and gas migrate into the folded porous and permeable layer and rise to the top. They cannot escape because of an overlying bed of impermeable rock.
Fault Trap, connection to oil
The formations then come to rest in such a way that, when petroleum migrates into one of the formations, it becomes trapped there. Often, an impermeable formation on one side of the fault moves opposite a porous and permeable formation on the other side. The petroleum migrates into the porous and permeable formation. Once there, it cannot get out because the impervious layer at the fault line traps it.
What is an Oil Spill?
An oil spill is the release of a liquid petroleum hydrocarbon into the environment due to human activity and is a form of pollution.
Oil pollution is caused by
any spillage of petroleum or its refined products.
Terrestrial Spills
When oil spills onto land*
The cycle of what happens to spilled oil in water/environment
Depending on their chemical and physical
characteristics, various hydrocarbon fractions will selectively evaporate, spread
over the surface, dissolve into water, accumulate as persistent residues, or be
degraded by microorganisms and solar ultraviolet radiation
Evaporation (oil)
Gets rid of 100% gasoline, 30-50% crude oil, 10% bunker fuel
Spreading
refers to the movement of an oil slick over the surface of water or land.
Dissolution
causes pollution of the water beneath an oil slick.
Residual materials(oil)
remain after the lighter fractions of spilled petroleum have evaporated or dissolved.
Degradation (oil)
refers to the slow decomposition of spilled materials by microorganisms and by photo-oxidation by solar ultraviolet radiation.
Acute toxicity caused by petroleum, refined products, or pure hydrocarbons is typically associated
with the ingestion of the materials, followed by the destruction
of cellular membranes, which results in the death of tissues.
Methods of cleaning oil spills
Contain, Vacuum, Absorb, Bioremediation, Controlled burning, Dispersants, Dredging, Skimming
Contain (Oil)
spill with oil booms. Booms are giant styrofoam logs wrapped in plastic that act like a floating fence.
Vacuum (Oil)
up spilled oil with skimmer boats. A skimmer is a boat with special
equipment that collects oil from the surface of calm waters.
Absorb (Oil)
the oil with sawdust, straw, foam chips, or other sorbents.
Bioremediation (Oil)
use of microorganisms or biological agents to break down or remove oil
Controlled burning (Oil)
can effectively reduce the amount of oil in water, if done properly. But it can only be done in low wind and can cause air pollution.
Dispersants
act as detergents, clustering around oil globules and allowing
them to be carried away in the water. This improves the surface
aesthetically and mobilizes the oil. Smaller oil droplets, scattered by
currents, may cause less harm and may degrade more easily. But the
dispersed oil droplets infiltrate into deeper water and can lethally
contaminate coral. Recent research indicates that some dispersants are
toxic to corals.
Dredging
for oils dispersed with detergents and other oils denser than water.
The process of gathering oil off the ocean floor or water source floor
Skimming
a machine that separates a liquid or particles floating on another liquid (requires calm waters).
A boom is
a floating barrier.
It is used to stop the oil spreading. It is cheap and effective. It works best in calm water.
high pressure hoses can be used to…
clean oil from beaches and rocky coastlines
Properties of Oil that Affect Cleanup
Viscosity, Density, Absorptivity
What are dispersants?
Dispersants applied to surface oil slicks break up the slicks and move the
oil, in the form of tiny droplets, from the water surface down into the
water column (the volume of water extending from the surface to the
bottom).
How Do Dispersants Work?
Like detergent soaps used to clean grease from your dishes.
Contain molecules with a water-compatible (“hydrophilic”) end and an oilcompatible (“lipophilic”) end.
By attaching to the oil, interfacial tension is reduced between oil and water,
breaking up the oil slick.
What Happens to Dispersed Oil?
Initially, dispersed oil moves down into the water column to depths ranging
from 1 to 10 meters (about 3 to 30 feet). Eventually, dispersed oil droplets degrade into naturally occurring substances. (which happens due to bacteria colonizing the oil)
What Constraints Affect Dispersant Use?
The effectiveness of a given dispersant depends on the type of oil spilled (it is
easier to disperse lighter oils), weather conditions, and how quickly dispersants
can be applied once oil has spilled.
Heavier oils or highly emulsified oils, are less amenable to successful dispersion
Environmental Impacts of Dispersant Use
Both dispersants and dispersed oil particles are toxic to some marine
organisms. But because concentrations of dispersed oil are quickly diluted in
the ocean, organisms are likely to be exposed only for short time periods.
Damaging Effects of Oil Spills
- Oil on the water’s surface can catch on fire and pollute the air.
- Oil can sink to the ocean floor and destroy the habitats of sea animals.
- Oil can react with oxygen in the air to form acids that are carried by wind and eventually fall back to the ground as acid rain.
- Oil washes up on beaches and marshes resulting in life threatening habitats for wildlife species.
- Sea turtles, birds, whales, fish, otters and other animals can become oil-soaked and die.
- Deer, bears, wolves, dogs, and cats can die from eating oil-soaked beach plants and animal carcasses.
How do oil spills effect birds?
The most common cause of death of seabirds results from their feathers
becoming oiled when they dive through or swim in oil-polluted water. This
causes the birds to lose critical insulation and buoyancy, and they die from
excessive heat loss leading to hypothermia or by drowning.
* They also ingest toxic oil while attempting to clean their feathers by
preening.
READ Slide #8 pg 42-43 Impact on specific marine habitats
- Plankton is a term applied to floating plants and animals carried passively by
water currents in the upper layers of the sea. Their sensitivity to oil pollution has
been demonstrated experimentally. - Some marine mammals and reptiles, such as turtles, may be particularly
vulnerable to adverse effects from oil contamination because of their need to
surface to breathe and to leave the water to breed. - Adult fish living in near shore waters and juveniles in shallow water nursery
grounds may be at greater risk to exposure from dispersed or dissolved oil. - The impact of oil on shorelines may be particularly great where large areas of
rocks, sand and mud are uncovered at low tide. - The amenity value of beaches and rocky shores may require the use of rapid and
effective clean-up techniques, which may not be compatible with the survival of
plants and animals. - Marsh vegetation shows greater sensitivity to fresh light crude or light refined
products whilst weathered oils cause relatively little damage. - Oiling of the lower portion of plants and their root systems can be lethal
whereas even a severe coating on leaves may be of little consequence especially
if it occurs outside the growing season. - The effects of oil on corals and their associated fauna are largely
determined by the proportion of toxic components, the duration of oil
exposure as well as the degree of other stresses. - The waters over most reefs are shallow and turbulent, and few clean-up
techniques can be recommended. - Birds which congregate in large numbers on the sea or shorelines to
breed or feed are particularly vulnerable to oil pollution. - Although oil ingested by birds during preening may be lethal, the most
common cause of death is from drowning, starvation and loss of body
heat following damage to the plumage by oil.
Exxon Valdez Oil Spill
However, the Exxon Valdez, the newest
tanker in the Exxon fleet, was incompetently steered onto a submerged reef,
resulting in a spill of 36-thousand tonnes of its 176-thousand t load of
petroleum. About 40% of the spill washed onto shoreline habitat of Prince
William Sound, while 25% was carried out of the sound by currents, and
35% evaporated at sea. Less than 10% was recovered or burned at sea.
How can oil tanker spills be prevented?
- Double lined bottom instead of single metal layer.
- Separate compartments for oil storage. In a double-hull tanker, the cargo tanks are separated from the ships outer hull to protect against the impact of an accident.
How can oil spill be prevented in transportation through training of tanker crews. The things trained.
*Inspection
* Develop better emergency procedures.
* Improve navigation skills.
* Highly trained marine pilots to guide vessels
* Aerial monitoring activities
OIL SPILL IMPACTS
- Oiled birds and marine life
- Habitat disruption
- Fish, Shrimp, Crab, Oyster Beds
- Estuarine disruption
- Food chain issues
RECOVER & REMEDIATION
Deepwater Horizon Spill
- Skimming
- Burning
- Dispersants
-Natural
*Evaporation
*Dissolution
*Bacterial action
*Sinks to bottom
