Oil and Natural Gas Notes
Crude oil (Petroleum) and Natural Gas – liquid or gaseous hydrocarbons formed form organic sediment changed by
heat and pressure and forced toward the surface. Found around porous coarse grained rock such as sandstone or porous
limestone and held below the surface by a trap (see diagram pg. 437 and draw below)
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Oil
Crude- oil from the ground, which must be refined
The world reserve should be depleted in about the next 40- 60 years at the present rate of use. An 80% depletion rate
is expected by 2055.
The process of heating the crude to separate and collect components which are processed to produce gasoline and
heating oil, or to make plastic, Styrofoam, jet fuel, lubricants for transportation and many other products.
Sweet vs. Sour crude – sweet is easier to refine and worth more
Light vs. Heavy crude – light produces more gasoline than heavy
Wells are drilled to extract crude from the ground- wells hit peak production when the pressure drops (U.S. oil
production peaked in the 70s’)
Texas, Louisiana, California, and Alaska produce most of the nation’s oil (Alaska and offshore regions still have
untapped reserves)
Close to 70% of oil in U.S. is used for transportation
U.S. is using ethanol (grain alcohol) as a gasoline extender or substitute
2005 foreign oil supplied 60% of U.S. oil consumption (27% in 85’ and 48% in 97’
Foreign oil prices are controlled mostly by (OPEC) – 11 countries – Saudi Arabia has 25% of the world reserve
World consumption is close to 70 million barrels a day.
What will happen when the world reserves hit peak production?
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Natural Gas
Some new reserves are still being found and should last for at least 60- 80 years at the current rate of use.
Areas that contain oil usually contain natural gas
Consumption began after the first welded pipeline in 1925
U.S. demand grew rapidly after WWII
Consumption has been rising since 1986
Transported by pipeline or condensed for ships or trucks (pipeline system throughout the U.S.)
Used in preparing many products and is being used more for electricity
Still used mostly in many industries as an energy source
It is the cleanest burning and highest heat producer of all fossil fuels – most expensive
U.S. is the top consumer of natural gas and imports some from Canada
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Environmental Impacts of Oil and Natural Gas
Drilling causes destruction and subsidence (sinking) of land when oil and gas are removed
Surface and ground water are polluted during runoff and infiltration
Offshore drilling of oil causes seepage into the ocean
Shipping accidents can cause massive oil spills in the ocean killing marine life
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Ex. Exxon Valdez crashed in Prince William Sound in Alaska in 1989 releasing 250,000 barrels of oil in the
sea
The burning of oil (gasoline) and natural gas cause air pollution