How is petroleum made

As the microscopic phytoplankton died, they sank to the bottom and accumulated in large quantities in the oxygen-free sediments. Over time, they were buried deeper and subjected to a long process of chemical conversion by bacterial decomposition and maturing under a thickening pile of sediment.

This caused the formation of liquid and gaseous hydrocarbons in the source rock. One of the products of anaerobic decomposition of organic matter is kerogen, which at high temperature and pressure slowly generates oil and gas.

After more than a hundred million years of erosion and sedimentation, the source rock may be buried under several kilometres of clay and sand deposits. As oil and gas form, they seep out of the source rock.

Because hydrocarbons are lighter than water, the oil and gas migrate upwards in porous water-bearing rock. Oil and gas migration takes thousands of years, and may extend over tens of kilometres until it is stopped by impermeable layers of rock, or the oil or gas leaks out into the sea.

Reservoir rocks are porous and always saturated with water, oil and gas in various combinations. The main reservoirs of the Gullfaks, Oseberg and Statfjord fields are in the large Brent delta that formed in the Jurassic.

There are also large reservoirs in sand that was deposited on alluvial plains during the Triassic Period the Snorre field , in shallow seas in the Late Jurassic the Troll field and as subsea fans during the Paleogene Period the Balder field.

In the southern part of the North Sea, thick layers of chalk composed of microscopic calcareous skeletons of plants and animals form an important reservoir rock, as in the Ekofisk Field. Oil platforms left underwater can pose dangers to ships and divers. Fishing boats have had their nets caught in the platforms, and there are concerns about safety regulations of the abandoned structures. Environmentalists argue that oil companies should be held accountable to the commitment they originally agreed upon, which was to restore the seabed to its original condition.

By leaving the platforms in the ocean, oil companies are excused from fulfilling this agreement, and there is concern this could set a precedent for other companies that want to dispose of their metal or machinery in the oceans. Petroleum and the Environment: Bitumen and the Boreal Forest Crude oil does not always have to be extracted through deep drilling. If it does not encounter rocky obstacles underground, it can seep all the way to the surface and bubble above ground.

Unfortunately, because bitumen contains high amounts of sulfur and heavy metals, extracting and refining it is both costly and harmful to the environment. Bitumen is about the consistency of cold molasses, and powerful hot steam has to be pumped into the well in order to melt the bitumen to extract it.

Large quantities of water are then used to separate the bitumen from sand and clay. This process depletes nearby water supplies. Releasing the treated water back into the environment can further contaminate the remaining water supply.

Processing bitumen from tar sands is also a complex, expensive procedure. It takes two tons of oil sands to produce one barrel of oil. A small percentage is used for roofing and other products. The Athabasca Oil Sands are the fourth-largest reserves of oil in the world. Unfortunately, the bitumen reserves are located beneath part of the boreal forest, also called the taiga. This makes extraction both difficult and environmentally dangerous.

The taiga circles the Northern Hemisphere just below the frozen tundra, spanning more than 5 million square kilometers 2 million square miles , mostly in Canada, Russia, and Scandinavia. It accounts for almost one-third of all of the forested land on the planet. Every spring, the boreal forest releases immense amounts of oxygen into the atmosphere and keeps our air clean. It is home to a mosaic of plant and animal life, all of which depend on the mature trees, mosses, and lichen of the boreal biome.

Surface mines are estimated to only take up 0. Refining Petroleum Refining petroleum is the process of converting crude oil or bitumen into more useful products, such as fuel or asphalt. Crude oil comes out of the ground with impurities, from sulfur to sand. These components have to be separated.

This is done by heating the crude oil in a distillation tower that has trays and temperatures set at different levels. Propane, kerosene, and other components condense on different tiers of the tower, and can be individually collected.

They are transported by pipeline, ocean vessels, and trucks to different locations, to either be used directly or further processed. Petroleum Industry Oil was not always extracted, refined, and used by millions of people as it is today. However, it has always been an important part of many cultures. The earliest known oil wells were drilled in China as early as CE. The wells were drilled almost meters feet deep using strong bamboo bits. The oil was extracted and transported through bamboo pipelines.

It was burned as a heating fuel and industrial component. Chinese engineers burned petroleum to evaporate brine and produce salt. On the west coast of North America, indigenous people used bitumen as an adhesive to make canoes and baskets water-tight, and as a binder for creating ceremonial decorations and tools.

By the 7th century, Japanese engineers discovered that petroleum could be burned for light. Oil was later distilled into kerosene by a Persian alchemist in the 9th century.

During the s, petroleum slowly replaced whale oil in kerosene lamps, producing a radical decline in whale-hunting. The modern oil industry was established in the s. The first well was drilled in Poland in , and the technology spread to other countries and was improved.

The Industrial Revolution created a vast new opportunity for the use of petroleum. Machinery powered by steam engines quickly became too slow, small-scale, and expensive. Petroleum-based fuel was in demand.

The invention of the mass-produced automobile in the early 20th century further increased demand for petroleum. Petroleum production has rapidly increased. In , the U. By , that number was million barrels per year.

Today, the U. According to OPEC, more than 70 million barrels are produced worldwide every day. That is almost 49, barrels per minute.

Although that seems like an impossibly high amount, the uses for petroleum have expanded to almost every area of life. Petroleum makes our lives easy in many ways. In many countries, including the U. The United States consumes more oil than any other country.

This is more than all of the oil consumed in Latin America 8. Petroleum is an ingredient in thousands of everyday items. The gasoline that we depend on for transportation to school, work, or vacation comes from crude oil. A barrel of petroleum produces about 72 liters 19 gallons of gasoline, and is used by people all over the world to power cars, boats, jets, and scooters. Diesel-powered generators are used in many remote homes, schools, and hospitals. Petroleum is found in recreational items as diverse as surfboards, footballs and basketballs, bicycle tires, golf bags, tents, cameras, and fishing lures.

Petroleum is also contained in more essential items such as artificial limbs, water pipes, and vitamin capsules. In our homes, we are surrounded by and depend on products that contain petroleum. House paint, trash bags, roofing, shoes, telephones, hair curlers, and even crayons contain refined petroleum.

Carbon Cycle There are major disadvantages to extracting fossil fuels, and extracting petroleum is a controversial industry. Carbon constantly cycles between the water, land, and atmosphere. Carbon is absorbed by plants and is part of every living organism as it moves through the food web.

Carbon is naturally released through volcanoes, soil erosion, and evaporation. Not all of the carbon on Earth is involved in the carbon cycle above ground. Vast quantities of it are sequestered, or stored, underground, in the form of fossil fuels and in the soil. However, that budget is falling out of balance.

Since the Industrial Revolution, fossil fuels have been aggressively extracted and burned for energy or fuel. This releases the carbon that has been sequestered underground, and upsets the carbon budget. This affects the quality of our air, water, and overall climate. The taiga, for example, sequesters vast amounts of carbon in its trees and below the forest floor. Drilling for natural resources not only releases the carbon stored in the fossil fuels, but also the carbon stored in the forest itself.

Combusting gasoline, which is made from petroleum, is particularly harmful to the environment. Every 3. Gasoline and diesel also directly pollute the atmosphere. They emit toxic compounds and particulates, including formaldehyde and benzene. People and Petroleum Oil is a major component of modern civilization. In developing countries, access to affordable energy can empower citizens and lead to higher quality of life.

Petroleum provides transportation fuel, is a part of many chemicals and medicines, and is used to make crucial items such as heart valves, contact lenses, and bandages. Peak oil is the point when the oil industry is extracting the maximum possible amount of petroleum. After peak oil, petroleum production will only decrease. After peak oil, there will be a decline in production and a rise in costs for the remaining supply. Measuring peak oil uses the reserves-to-production ratio RPR.

This ratio compares the amount of proven oil reserves to the current extraction rate. The reserves-to-production ratio is expressed in years. The RPR is different for every oil rig and every oil-producing area. Oil-producing regions that are also major consumers of oil have a lower RPR than oil producers with low levels of consumption. The oil-rich, developing nation of Iran, which has a much lower consumption rate, has an RPR of more than 80 years.

It is impossible to know the precise year for peak oil. Some geologists argue it has already passed, while others maintain that extraction technology will delay peak oil for decades.

Many geologists estimate that peak oil might be reached within 20 years. Petroleum Alternatives Individuals, industries, and organizations are increasingly concerned with peak oil and environmental consequences of petroleum extraction. Alternatives to oil are being developed in some areas, and governments and organizations are encouraging citizens to change their habits so we do not rely so heavily on oil.

Bioasphalts, for example, are asphalts made from renewable sources such as molasses, sugar, corn, potato starch, or even byproducts of oil processes. Although they provide a non-toxic alternative to bitumen, bioasphalts require huge crop yields, which puts a strain on the agricultural industry.

Algae is also a potentially enormous source of energy. Algae grows extremely quickly and takes up a fraction of the space used by other biofuel feedstocks. About 38, square kilometers 15, square miles of algae—less than half the size of the U. Algae absorbs pollution, releases oxygen, and does not require freshwater. The country of Sweden has made it a priority to drastically reduce its dependence on oil and other fossil fuel energy by Experts in agriculture, science, industry, forestry, and energy have come together to develop sources of sustainable energy , including geothermal heat pumps, wind farms, wave and solar energy, and domestic biofuel for hybrid vehicles.

The pits have preserved fossils of saber-toothed cats, mastodons, turtles, dire wolves, horses, and other plants and animals that were trapped in the sticky substance 40, years ago.

Bitumen continues to bubble up through the ground today. A petroleum play is a group of oil fields in a single geographic region, created by the same geologic forces or during the same time period. A petroleum play may be defined by a time period Paleozoic play , rock type shale play , or a combination of both. Saudi Arabia 2. Venezuela 3. Canada 4. Iran 5. Iraq Source: U. Energy Information Administration. Leading Petroleum Producers 1. Russia 3. United States 4.

China Source: U. Leading Petroleum Consumers 1. United States 2. China 3. Japan 4. India 5. Use of energy. Energy and the environment.

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