There are three stages of oil extraction; Primary, Secondary, and Tertiary. During the primary extraction, reservoir drives are in place. These are the natural pressure methods that drive the oil out after drilling, i.e. natural gas and water. During the secondary extraction, mechanical methods are used, such as injecting air or gas into the well to increase pressure. During the final stage, heat and chemicals are used to help heat the oil and increase its flow.
Some of the environmental effects of extracting oil are air pollution, greenhouse gasses, and oil spills. When crude oil is refined, toxins are released into the atmosphere. These toxins are dangerous to humans and our ecosystem. Burning oil produces greenhouse gasses that increase global warming. Large oil spills can be catastrophic to the environment, but most of the oil spilled in our ecosystem is from illegal dumping and leaking automobiles, airplanes, and boats.
Oil is the largest source of energy in the United States, providing close to 40 percent of all of the nations entire power needs. (Pace University, 2000) Most oil is used for home heating or transportation, but a small amount is used as fuel for electricity producing plants. There are three ways to convert oil into electricity; Conventional steam, combustion turbine, and combined-cycle technology. Each of these methods involves burning the oil, which in turn, pollutes the air, land and water.
Sources:
Helman, C. (2010, January 21). The World's Biggest Oil Reserves. Retrieved February 8, 2014, from