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Oil
Oil Oil use is rising
drastically worldwide, accounting for 37% of the world’s energy
Crude oil, or petroleum, is made of a mixture of various types of hydrocarbons• oil refineries sort the oil
into different types, such as gasoline, tar, and asphalt
Extracting Oil Once geologists
have discovered an oil deposit, a company will conduct exploratory drilling• Oil is trapped
under pressure, and when a hole is drilled, oil will rise to the surface unassisted
Extracting Oil After primary
extraction, as much as 2/3 of the oil may remain
Secondary extraction involves solvents or water to flush out underground rocks and remove additional oil• This is expensive and
often is not done
Offshore Drilling Over 25% of the oil
and gas extracted in the US comes from offshore drilling sites
Floating or fixed platforms are built above the drilling site
Oil in Alaska
The northern slope of Alaska is a virtually untouched wildlife area
It also contains unknown amounts of oil
Since the 1920s, people have debating what to do with this resource: preserve the undisturbed natural area or drill for oil
Oil in Alaska
Small areas have been drilled and over 14 billion barrels of crude oil have been extracted• The oil is then
transported across Alaska via the trans-Alaska pipeline to oil tankers
Oil in Alaska The Arctic National
Wildlife Refuge (ANWR) is a federally protected area• It is home to 160
nesting bird species, fish and marine mammals, timber wolves, musk oxen, etc
• It is also a vital birthing area for caribou
Oil in Alaska
ANWR has been the focus of a debate for years and US policy has changed
In 1980, Congress put most of the refuge off-limits to oil but reserved for future decision-making a large coastal area
Since 2005, Congress has attempted to open the refuge to drilling but has been blocked
Refining Crude Oil
Refining separates the hydrocarbons into classes of different sizes
Different components of crude oil boil at different temperatures
Environmental Effects of Oil Drilling has
minor impacts, but roads and infrastructure must be built• This causes
major habitat alteration
Oil spills and other problems may cause additional damage
Environmental Effects in ANWR
Many scientists anticipate damage to vegetation and wildlife if drilling takes place
There are methods that can lessen the impact, such as building roads of ice that will melt in the summer and only drilling in the winter when caribou are not present
Natural Gas
Natural Gas Natural gas
is the fastest growing fossil fuel in use today• Supplies are projected to last around 60 years
Natural gas consists mostly of methane (CH4) and small amounts of other volatile hydrocarbons
Using Natural Gas
Natural gas was first used in the 1800s, but was not used wide scale
Today, it is used for heating and cooking
Types of Natural Gas
Biogenic gas—created by anaerobic decomposition at shallow depths• Can also be made from the decay of landfills—now is being sold
Types of Natural Gas
Thermogenic gas—results from compression and heat deep underground• May be formed near crude oil or from crude oil that is altered by heating
Extracting Natural Gas
Pumps are used to create pressure and pull natural gas and oil to the surface
Many of the easily accessible natural gas reserves have already been used up
Fracking