Petroleum

Petroleum, also called crude oil or simply oil, is a natural resource. It looks like a yellowish-black liquid and is found deep in the Earth. It is made mostly of hydrocarbons. It is a fossil fuel formed over millions of years from old plants and animals, especially tiny creatures like algae, that were buried and changed by nature.

After it is taken from the ground, oil is cleaned and separated into many useful products. These include fuels like gasoline, diesel, kerosene, and jet fuel. Other products are bitumen, paraffin wax, lubricants, and materials used to make plastics. It is also used to make solvents, fabrics, refrigerants, paint, synthetic rubber, fertilizers, and many other important things. Petroleum helps make many things we use every day.

Petroleum is a non-renewable resource, meaning we cannot make more of it. Using it can hurt the natural environment and the climate system. When we take it out of the ground, clean it, and burn it, it can release gases that change the climate and cause pollution.

Etymology

The word petroleum means "rock oil". It comes from two older words: petra, for "rock", and oleum, for "oil". People began using this word a long time ago in places like monasteries in southern Italy. The name became common when the oil industry started growing in the 1800s.

You can read more about it in books like De Natura Fossilium by Georg Bauer.

History

Main article: History of the petroleum industry

People have used petroleum for thousands of years. Over 4,300 years ago, the Sumerians used a substance called bitumen to build boats. Ancient people in places like Babylon used petroleum for building and medicine. In China, people began using oil for fuel more than 2,000 years ago.

In the 1800s, people started drilling wells to find oil on purpose. One of the first wells was dug in Poland in 1853. In 1859, an American named Edwin Drake drilled the first oil well in Pennsylvania. This started a big increase in oil use around the world. During the 20th century, oil became very important for vehicles and many industries. Today, oil is still a very important resource. Countries like the United States, Russia, and Saudi Arabia produce the most.

Composition

Petroleum is made up of different kinds of liquids, gases, and solids. The lighter parts are gases like methane, propane, and butane. Most of the liquid and solid parts are heavier organic compounds, especially hydrocarbons, which are made of carbon and hydrogen.

When oil comes out of a well, it is mostly crude oil. Because the pressure is lower at the surface, some gas comes out and can be collected or burned. In places with hot underground temperatures, gas may contain heavier hydrocarbons like pentane and hexane, which look like gasoline. These are called natural-gas condensate. Different oils have different mixes of these parts, which affects how they work.

Formation

Petroleum is a fossil fuel made from old plants and tiny sea creatures called zooplankton and algae. These organisms died and sank to the bottom of ancient seas or lakes long ago.

They got buried under layers of mud and water with very little oxygen. This stopped most bacteria from breaking them down.

As more layers built up, heat and pressure grew. This changed the buried plants and animals into a waxy material called kerogen. With even more heat and pressure deep underground, kerogen turned into the liquid we call petroleum. This slow change happened over millions of years, using heat from deep inside the Earth.

Some scientists once thought petroleum could form without any living things, but most evidence shows it comes from ancient plants and creatures.

Reservoirs

For oil to be found and collected, three important things need to be in place. First, there needs to be a rock layer that can turn into oil when heated deep underground. Second, there needs to be a special kind of rock that can hold the oil. And third, there needs to be a layer above that keeps the oil from escaping to the surface.

Inside these special rock places, oil, water, and gas usually settle into layers. Oil often moves upward through rocks until it gets trapped, forming an oil field. We get oil by drilling deep wells into these traps. At first, the natural pressure in the rock helps push the oil up, but later we may need to use water or other methods to help bring more oil to the surface.

Classification

See also: Benchmark (crude oil)

The petroleum industry sorts crude oil by where it is found, how thick it is, and how much sulfur it has. Oil can be light (less thick), heavy (more thick), or medium. It is called sweet if it has little sulfur and sour if it has a lot. Light and sweet oil is more valuable because it is easier to change into fuels like gasoline.

Some common examples of oil used as standards around the world include:

• West Texas Intermediate (WTI), a high-quality oil used in North America.
• Brent Blend, a mix of oils from the North Sea.
• Dubai-Oman, used for oil in the Middle East going to Asia.
• Tapis (from Malaysia).
• Minas (from Indonesia).
• The OPEC Reference Basket, an average of oils from several countries.
• Midway Sunset Heavy, used for heavy oil in California.
• Western Canadian Select, used for heavy oil in Canada.

While these are the standards, the oil actually traded often differs and may be priced lower than these benchmarks.

Use

Once we get oil from the ground, we clean it and separate it into many useful products. We use a process called distillation to do this. Some of these products are gasoline, diesel, and kerosene. We use these for fuel in cars and machines. We also use oil to make plastics, medicines, and products that help plants grow. Most oil is used to make fuels for engines.

Oil has a lot of energy and is easy to move from place to place. That’s why it became very important for energy in the middle of the 1900s. We use oil to make fuels like gasoline, diesel, and jet fuel. These fuels help keep things running. Oil is also used to make lubricants, which help machines work better.

Many medicines are made from oil after going through several steps. Modern healthcare uses oil for important ingredients. Almost all products that help plants grow and many plastics come from oil. Plastics and other synthetic materials are made from molecules found in oil.

Industry

In the 1950s, it cost a lot to ship oil from the Persian Gulf to the United States. But in the 1970s, big ships called supertankers made shipping much cheaper. By 2010, shipping cost was only a small part of the price.

Crude oil is bought and sold as a future on the NYMEX and ICE exchanges. These are special agreements where people agree to buy or sell oil in the future. Each agreement is for 1,000 barrels of oil and can be planned up to nine years ahead.

Use by country

The world uses a lot of petroleum, also called oil. Oil comes from ancient plants and tiny sea creatures that lived millions of years ago.

Different countries use and produce different amounts of oil. Some countries make more oil than they need and sell the extra to others. Other countries need to buy oil because they don’t have enough of their own. This helps people and machines all over the world run smoothly.

Main articles: List of countries by oil extraction, List of countries by proven oil reserves

See also: Fossil fuel exporters and OPEC

Environmental effects

Main article: Environmental impact of the petroleum industry

Burning petroleum releases gases that warm our planet and affect the air we breathe. These gases, especially from oil and coal, have caused the air to hold more carbon dioxide than it has in a very long time. This warming changes weather patterns and melts ice in places like the Arctic.

When oil is taken from the ground or ocean, it can sometimes harm the nearby environment. Accidents, like when ships carrying oil crash, can spill oil into the water. These spills cover beaches and hurt animals that live in the water. Even smaller spills can damage plants and animals. Cleaning up these spills is very hard and needs many people working together.

Alternatives

Electric vehicles are a good choice for cars, and biojet fuels can be used for airplanes. Single-use plastics can hurt the environment and pollute the oceans, but people are looking for better ways to replace them.

Main articles: Electric vehicles, biojet, Single-use plastics

International relations

See also: 2022 boycott of Russia and Belarus

Control of petroleum has shaped international relations for much of the last century. Groups like OPEC have played a big role in world politics. As renewable energy grows and we work to protect our climate, some think countries that rely on oil might see their influence change in the future.

Main articles: oil war and Petro-aggression

Petroleum production has sometimes been linked to conflicts. Since oil is only found in a few places, arguments over oil and land have led to disagreements and wars, like during the 2020 Russia–Saudi Arabia oil price war and the Iran–Iraq War.

Future production

The use of oil, especially for cars, has grown a lot over the past century. Even when there was plenty of oil, people still bought cars that used less fuel. But economic troubles in 2008 slowed this down.

Experts think that demand for oil might drop in the future, especially as countries like China grow and change. Some groups are pushing to use less oil because they worry about its future. This could make it harder to find and use new oil.

We may also see changes in how oil is found and used. Some places have lots of oil but need special technology to get it out. As we use more of these places, it might become more expensive. Some believe that at some point, we may not be able to get as much oil as we used to, especially as the world starts using more clean energy instead.

Main article: Peak oil

Hydrocarbons on other worlds

On Saturn's largest moon, Titan, there are lakes filled with special liquids called hydrocarbons, like methane and ethane. The space probe Cassini–Huygens discovered these lakes hold a lot of these liquids.

In 2015, the Curiosity rover's Mars Science Laboratory took samples from the surface of Mars. These samples showed tiny bits of organic molecules.

In fiction

Petroleum, often called oil, appears in many stories and books. Writers use it to show how important this resource is for our world. In tales, oil can be a source of adventure, mystery, or even conflict, showing its big role in real life.