Despite the misconception that it comes from dinosaurs, crude oil forms when microorganisms, such as algae and plankton, are subjected to high pressure and high temperature while buried under layers of sediment.

Demystifying the claim that crude oil is inorganically created and a renewable resource

The abiogenic petroleum theory holds that fossil fuels originate in Earth's mantle and are constantly replenished, rather than formed by microorganisms over millions of years. While inorganic chemical processes can produce simple hydrocarbons, the range of complex molecules found in crude oil suggests an origin from a diverse set of organisms. Isotope analyses of these molecules also support the model that they originated from living things that preferentially take up certain isotopes over others.

An overview of crude oil, including its constituent hydrocarbons and refinement outputs

The mixture is primarily composed of molecules of carbon and hydrogen atoms bonded into a variety of shapes and lengths, giving each different chemical properties, such as boiling points. Refining can remove elemental impurities—such as sulfur—after hydrocarbons are separated, ensuring the resulting products can be used effectively in other machines, such as car engines.

To use the various chemicals in crude oil, they must often be cracked—broken down into smaller molecules—to make their processing easier in everyday machines.

View a sample of objects surprisingly derived from crude oil, including chewing gum and lipstick

Crude oil processing produces a variety of fuels and the building blocks for plastics, but it also distills out the hydrocarbons used to make aspirin, Teflon, vinyl, crayons, candles, Tupperware, roofing shingles, asphalt pavement, hair dye, anesthetics, food-grade lubricants, polyester, synthetic rubber, and resins for items like dentures.

Crude oil is the type of oil used to create fuel like gasoline, heating oil, and more

Technically speaking, crude oil is unrefined petroleum. This article dives into the different ways it’s categorized (by density, sulfur content, and origin), and how the combinations of these types of oil are used.

Oil and natural gas from fracking is considered unconventional

This method forcibly extracts fossil fuels from tightly packed rocks, where they form from organic matter that has undergone extreme heat and pressure. Conventional drilling, on the other hand, waits for the oil and gas to escape from shale and accumulate in more porous and permeable rocks, such as limestone.

Early Earth lifeforms likely made energy via mineral reactions, not sunlight

Earth's initial atmosphere was filled with carbon dioxide, methane, and water, with most oxygen locked away in the rocky crust. Over time, bacteria evolved to slowly release that oxygen into the atmosphere by breaking down rock.

Abiogenesis explains how Earth's natural processes could have formed organic matter

The theory details how chemical interactions in hydrothermal vents and shallow ponds billions of years ago could have created lipids, proteins, and RNA. As these interactions involve water, life is thought to have started in oceans.

View the 45 gallons of refined products created from each 42-gallon barrel of crude oil

More than 85% is refined into fuels, such as gasoline and diesel, while about 10% is converted into raw materials for plastics, synthetic rubbers, and other essential products, such as lubricants. Because the majority of these products are less dense than the starting crude oil and additional inputs are introduced during the refining process, there is a processing gain of three gallons.

See where the 100 million barrels of crude oil the world consumes daily end up.

The recorded history of crude oil use dates back about 5,000 years, with the Babylonians using it to waterproof their boats and as mortar in the construction of structures.

Despite being derived from crude oil, which itself comes from organic material, synthetic plastic isn't biodegradable because it hasn't existed long enough for microbes to have developed mechanisms to break it down.

While major oil spills result from accidental pipeline ruptures or damage to transportation vessels or rigs, as much as half the oil that reaches coastlines has naturally leaked from the seafloor.

Learn about unconventional ways to clean up crude oil, including using moss and chickens

Studies show that microorganisms in chicken manure can break down the hydrocarbons in crude oil without producing toxic by-products. Scientists have also explored avoiding the environmental risks of chemical dispersants and synthetic adsorbents by using human hair and peat moss to adsorb crude oil, which can be taken up by their cuticles and porous structures, respectively.

The separation of crude oil into petroleum products begins by boiling it in a distillation tower, where constituent hydrocarbons are separated into layers based on the temperatures at which they boil.

The ins and outs of oil refining

The oil industry is broken up into the upstream, midstream, and downstream segments, and oil refining is part of the latter. “Downstream” refers to companies like Standard Oil that are converting crude oil into a finished product.

How microbes limited the damage and helped clean up the Deepwater Horizon oil spill

A bloom estimated to contain about 100 sextillion microbial cells broke down much of the 4.1 million barrels of spilled crude oil into nontoxic compounds in what was one of the most significant bioremediations of a human-made disaster. The microbes involved acted similarly to the first patented genetically modified organism in US history: an oil-eating bacterium engineered in 1971.

How disruptions in oil markets can drive up the price of everyday goods

Most types of plastic are made from polymers derived from chemicals produced by the processing and refining of crude oil and natural gas. Spikes in the cost of either fossil fuel raise the cost of wrappings, tubs, and other plastic containers for products.

Fracking provides access to fossil fuel reserves locked in underground rock

Using a pressurized fluid mixture that is over 90% water, cracks are created in shale about 2 miles deep to release trapped oil and natural gas. The process uses an average of 3 to 6 million gallons of water per well, which can strain local water supplies.

Scientists have collected critical minerals from ocean water using seaweed, a type of algae that leaves behind a mineral-rich powder called bio-ore after being processed into biofuels.

How crude oil is split across oil markets based on geographic origin

Brent, West Texas Intermediate, and Dubai are the three crude oil classes and differ in terms of typical refinery uses, density, sulfur content, and suitability for financial benchmarking. Brent, which originates in the North Sea, is traders' go-to benchmark, in part, because it is easily shipped and politically stable, and used to price most of the crude sold internationally.

An analysis of fossilized reefs from northern Africa and Germany suggests that shallow water corals and photosynthetic algae formed the mutualistic partnership seen today between 419 and 359 million years ago.

Evidence suggests the first cells on Earth were bacteria

About 4 billion years ago, these single-celled organisms harvested carbon dioxide and sunlight to produce their own food and oxygen, setting the stage for the evolution of oxygen-breathing life forms. Archaeabacteria, which thrive on inorganic molecules in extreme habitats on Earth today, were also among the earliest organisms.

Fossils form in environments where dead organisms can be rapidly buried

Such landscapes enable corpses to be encased by terrain before significant decay occurs. They are most commonly found in river deltas and sinking coastal regions, where sediments accumulate over time until geological forces expose the areas to erosion, revealing embedded fossils.

A guide to crude oil and natural gas extraction, from rig site preparation to land restoration

Requirements for traffic plans, access roads, and noise barriers vary by state and local laws, but once the rig site is prepared, the rig is assembled and digs a well that is then encased in steel and cement to protect groundwater reservoirs. After drilling and testing the extraction pipe, fracking fluid is injected into the rock to create cracks where crude oil resides, allowing it to be pumped out.

A case study of how engineers and geologists at Tullow Oil look for oil reserves

An analysis of surface rocks using aerial and satellite imagery can help narrow the search for crude oil by identifying basins where sedimentary layers have compacted—a key process in oil formation. Surveys that look for variations in Earth's gravitational and magnetic fields consistent with specific rock distributions, or that use sound waves reflected off rock layers—not unlike sonar underwater—can also help map subsurface geology.

Oil markets are seeing higher costs and lower prices amid tech breakthroughs

Experts say oil demand has not yet reached its peak. Recent technological breakthroughs in the oil industry include advances in drilling and extraction, as well as subsurface technologies.

Unless prices of fossil fuels rise significantly, their production is expected to slow

US oil and natural gas production skyrocketed from 2000 to 2020, largely due to advances in fracking. However, weak global energy prices have prevented this boom from translating into increased profits for fossil fuel companies.

Trace the rise of oil: from early drilling to today’s global power

This animated map video vividly illustrates how petroleum shaped global politics and industry—from 18th-century uses and 19th-century drilling booms in North America to today’s OPEC strategies, shale revolution, and geopolitical oil influence.

Explore a timeline of US dependence on crude oil from 1850 to 2023

Oil dependence began with the rise of oil as a commodity, followed by an era of geopolitical competition for the resource after World War II. The domestic fracking boom, which started around 2006, was driven by a desire to reduce the nation's dependence on international adversaries for energy.

The history of Earth's breathable atmosphere, made possible by photosynthetic bacteria

Between 3.2 billion and 2.8 billion years ago, threadlike microorganisms called cyanobacteria began consuming available water vapor, carbon dioxide, and sunlight to produce oxygen. However, molecules released from Earth's interior by volcanoes consumed this oxygen via chemical reactions, preventing it from accumulating until volcanism had sufficiently decreased about 2.4 billion years ago.

Decommissioned oil rigs have been repurposed into artificial reefs that serve as nursery habitats for fish, corals, sponges, and other invertebrates in the decades since their installation.

Geode formation begins with trapped gas bubbles in igneous or sedimentary rock

Over thousands or millions of years, water seeps into the cavity created by the bubble and deposits minerals, which slowly build and crystallize into quartz, agate, amethyst or other crystals.

Diamonds have been made from substances such as peanut butter and carbon dioxide, though they can be created from any carbon-rich material under extreme pressure and temperature.

View a breakdown of worldwide oil production since 1900, mostly led by the US

When analyzing the production of crude oil, shale oil, oil sands, and condensates since the start of the 20th century, Saudi Arabia produced more crude oil only in 1977, from 1979 to 1981, and from 1991 to 2016. Nations such as Iraq and the United Arab Emirates produced much smaller quantities than both Saudi Arabia and the US.

Many plastic products are molded from melted pellets called nurdles, which are made from ethylene and propylene extracted from crude oil.

Understanding why the US can't use its own crude oil and depends on global markets

Before advancements in fracking technology made lighter shale oil readily available, US refineries had been built and optimized for decades to process heavier oil from other countries with high profitability. Despite being able to refine lighter oil, US oil companies can operate with better margins by exporting it to other nations whose refineries are optimized for it and importing heavier oil, for which the US has the infrastructure.

Genetic analysis indicates that every organism on Earth evolved from a single cell

LUCA—the last universal common ancestor—lived about 4.2 billion years ago and likely obtained energy through the conversion of carbon dioxide and hydrogen gas consumed from atmospheric gases at the ocean's surface or hydrothermal vents—openings on the seafloor where fluid warmed and enriched with minerals by Earth's interior is expelled.

Diatomite, a sedimentary rock used as a filtration material in beer, wine, swimming pool water, motor oil, and pharmaceuticals, is formed from the fossilized shells of diatoms, a type of algae.

See a timeline that shows how volatile oil prices have been for decades, from OPEC-led embargoes in the 1970s and shale surges in the 2000s to the US flipping to become a net oil exporter in 2020.

About 10% of the world's crude oil and 32% of its natural gas is reached via fracking

Most of the world's shale oil resources—which are recoverable via fracking—are found in Russia, the US, China, Argentina, and Libya. The majority of equivalent shale gas resources are found in China, Argentina, Algeria, the US, Canada, and Mexico.

A four-billion-year-old meteorite reignited the debate about life on Mars

Recovered from Antarctica in 1984, ALH84001 contained organic compounds, magnetite and iron sulfide grains of potential biological origin, and features that resembled fossilized bacteria. With technological advancements, scientists found abiotic origins for these features in the following decades.

Scientists can determine Earth's past environmental conditions by analyzing sediment cores—accumulated layers of mud and remains of charcoal, pollen, plants, algae, and other organic material.

Oil shocks, war, and the 1970s crisis that remade American energy and economics

The oil crises of the 1970s—fueled by Middle East conflict and OPEC's dominance—triggered inflation, price controls, and policy failure. But they also accelerated fracking, alternative energy, and the rise of free-market economics.

Hypotheses on the origins of Earth's water, from comets and asteroids to magma oceans

Before Earth's atmosphere formed, any liquid water would have boiled off, preventing the accumulation of water early on to create today's oceans. Planetary scientists continue to debate whether this water was delivered later from comet or asteroid collisions or via reactions between iron oxide in Earth's molten surface and hydrogen gas from the planetary nebula.

Paleontologists apply rules about rock layering, fossilization, and radioactivity to date geological samples

Concepts such as the understanding that older rock layers will form beneath newer ones allow scientists to compare the ages of samples from various layers. Although no geological site preserves evidence across all time, samples can be combined with fossils of known age, such as those dated by analyzing the decay of their radioactive isotopes, to reconstruct Earth's timeline.

Molecules derived from algae can be found in foods such as ice cream, salad dressings, brownie mix, and gravies, as well as in products such as toothpaste, multivitamins, and egg substitutes.

Civilizations of the past mistook dinosaur fossils for dead mythological creatures

Without knowledge of evolution or extinction, people believed such fossils were the bones of massive animals no one had ever seen alive, including dragons and giants. It was not until the science of paleontology and studies of extinction that these ideas were overturned definitively.

Some algae have helped remove microplastics from water after being bioengineered to clump together with these contaminants, forming an easily collectible microplastic-algae sludge.

Fracking has led to an increased global oil supply, contributing to lower oil prices

Fracking technology has significantly increased how much crude oil the US produces. As more countries adopt fracking technology, there could be an increased downward pressure on prices—although fracking has been widely criticized for its negative environmental impacts.