Petroleum

Petroleum is a naturally occurring liquid found beneath the Earth’s surface that can be refined into fuel. Petroleum is a fossil fuel, meaning that it has been created by the decomposition of organic matter over millions of years. It is formed in sedimentary rock under intense heat and pressure. Petroleum is used as fuel to power vehicles, heating units and machines of all sorts, as well as being converted into plastics and other materials. Because of worldwide reliance on petroleum, the petroleum industry is extremely powerful and is a major influence on world politics and the global economy.

Petroleum and the extraction and processing of petroleum drives the world economy and global politics. The modern world owes its existence to petroleum. Some of the largest companies in the world are involved in the extraction and processing of petroleum, with other companies creating products that either require hydrocarbons to operate or are petroleum-based: plastics, fertilizers, automobiles, and airplanes. Asphalt, which is used to pave highways, is made from petroleum. Vehicles that drive on highways are made of materials derived from petroleum and run on fuels refined from petroleum.

Petroleum is most often associated with crude oil and the wells dug into the ground to bring that liquid to the surface. The liquid can vary in color: from relatively transparent to dark brown or black. Heavier oils are often the darkest in color. Petroleum contains various types of hydrocarbons, and natural gas is often found dissolved in the liquid in significant amounts. The hydrocarbons can be processed in refineries into different types of fuels. Hydrocarbon molecules in petroleum include asphalt, paraffin, and naphthene.

Petroleum is comprised of a mixture of various hydrocarbons, and can have different chemical and physical properties depending on where it is found in the world. In general, the more dense the petroleum the more difficult it is to process and the less valuable it is. “Light” crude is the easiest to refine and are generally considered the most valuable, while the viscosity of “heavy” crude makes it more expensive to refine. “Sour” crude contains sulfur and sulfuric compounds, which makes the fuel less valuable.

In the petroleum industry, petroleum companies are divided into upstream, midstream and downstream. Upstream deals with crude oil. Midstream refers to the storage and transport of crude oil and other more refined products. Downstream refers to products for consumers such as gasoline.

Petroleum use is embedded in modern life, but the extraction process and use of petroleum are toxic for the environment. Underwater drilling causes leaks, extraction from oil sands strips the earth or uses precious water and fracking destroys the water table. Transporting petroleum through pipelines has the potential to destroy the local environment and shipping petroleum risks spills and uses energy.

Global petroleum use has had a negative impact on the environment, as the carbon released into the atmosphere increases temperatures and is associated with global warming. Many products created with petroleum derivatives do not biodegrade quickly, and the overuse of fertilizers can damage water supplies.