Fossil fuels make up 80% of the world’s energy use. The main types of fossil fuels, coal, oil, and natural gas, have been used for hundreds of years. However, it is becoming clear how damaging these resources can be to the environment.
How are fossil fuels taken from the earth?
There are many ways to extract these non-renewable energy sources from the Earth. A company will locate coal, oil, or natural gas then drill into the Earth.
To extract fossil fuels, companies use chemicals, water, steam, sand, or a combination of all four. Fossil fuels are sometimes sent elsewhere for processing.
This article will break down all the various processes of extracting fossil fuels from the Earth.
It will also go over what fossil fuels are, types of fossil fuels, their history, and their uses today.
Table of Contents
What are Fossil Fuels?
Fossil fuel is made from decomposing plants and animals.
Once extracted from the Earth’s crust, fossil fuels are made into different forms of energy. They can be used as a heating element, to power machines, gas, and many other things.
This type of energy is a non-renewable energy source. Meaning there is a limited supply of fossil fuels. It takes millions of years for new fossil fuels to form, and waiting for that amount of time is impossible for humans.
Fossil fuels release carbon and other greenhouse gases into the atmosphere when burned.
Types of Fossil Fuels:
There are three main types of fossil fuels. They are:
- Coal: Usually found in sedimentary rock. Coal is made of many layers of plants and animals, 50% or more to be exact. Coal can be brown or black and range from hard to crumbly. This type of fossil fuel accounts for a third of the world’s energy. Depending on its carbon content, coal is classified into four categories: anthracite, bituminous, sub-bituminous, and lignite.
- Oil (petroleum): Oil is found initially in a solid state in between layers of sedimentary rock, and it is then heated to form the liquid substance that is more commonly known. Oil is used to make gas, diesel, and heating fuel. About 40% of the world’s oil supply comes from the United States, Saudi Arabia, and Russia.
- Natural gas: Natural gas is an odorless gas made mostly of methane and found in pockets of sedimentary rock, usually above an oil deposit. Fracking is a process used to remove natural gas from the Earth and has skyrocketed the production of this fossil fuel in the U.S.
History of Fossil Fuels
While ruling in the British Isles, the Roman empire found coal, and they used it to heat public baths. The Romans liked it so much they brought it back to Rome, and coal is still found in Roman ruins in Italy today.
However, coal was virtually forgotten about after the fall of the Roman empire, and it was not used again till the 1200s in London when a population boom made it hard to find firewood.
Then in the 1800s, we saw a rise in the use of fossil fuels such as coal and oil.
The Industrial Revolution started after the invention of the steam engine, and factories began to pop up everywhere. The first car and oil-based engine, the internal combustion engine, were made.
Since the Industrial Revolution, fossil fuel use has been rising.
Fossil Fuels Today
Fossil fuels still dominate the energy market today. Fossil fuels account for about 80% of the world’s energy.
It has also become clear how much damage fossil fuel use is doing to the environment. For example, 74% of the United States’s greenhouse gas emissions in 2019 were from burning fossil fuels.
Today oil is used in different fuel types, including the gas in our cars. It is also used to make pesticides, fertilizers, pharmaceuticals, and plastics. Coal and natural gas are used primarily for creating electricity.
The use of coal has been declining in part of the world, while oil and natural gas have risen.
How Are Fossil Fuels Taken from the Earth? By Type of Natural Resource
Each type of fossil fuel has its own way of being extracted from the Earth. Here is a breakdown of the three primary forms of fossil fuels.
There are two ways to mine coal; surface mining and underground mining.
This type of mining is used when the coal deposits are less than 200 feet under the ground. Miners use machines to dig through the topsoil to the coal deposits.
Once the coal gets extracted, the topsoil is put back to continue plant growth. Surface mining is the cheapest of the two ways to acquire coal from the Earth. As a result, it accounts for two-thirds of the United States’ coal production.
Underground mining (deep mining)
Underground mining is used when the coal is hundreds of feet below the surface. Miners will take an elevator down and ride a train to the coal deposits, and they then use a machine to extract the coal.
After the coal gets extracted using one of the two types of mining, it might be processed. Dirt, rocks, sulfur, ash, and other unwanted materials get removed in this process.
The process increases the heating value of the coal. However, processing coal is not a necessity.
There are many ways to extract oil from the Earth, and which process is used depends mainly on geology.
Surfacing mining is used when extracting oil sands (bitumen). This type of mining is utilized when the oil is less than 200 feet from the surface.
A giant mechanical shovel extracts the oil sand. Then, the oil sand is transported to “crushers,” where the sand gets mixed with hot water. The oil sand is then pumped through an “upgrader,” where the oil is separated from unwanted contents like sand, clay, and water.
Tilling ponds might be used in surface mining. After the oil sands are mixed with the hot water, the mixture is pumped into a pond.
Here the sand and clay will gradually sink, and the water will rise. The water is then reused in the following process. After the pond is not needed, it is reclaimed. The pond is dried out, covered with topsoil, and planted with local trees and plants.
In Situ Recovery
This type of extraction is used when the sand oil is much deeper in the Earth.
The bitumen is separated from the sand under the ground instead of being brought somewhere else to be separated. There are two ways to do this; steam-assisted gravity drainage (SAGD) and cyclic steam stimulation (CSS).
SAGD is the most used way of in situ recovery. In this process, there are two wells; the injection well and the production well. The injection well is drilled vertically and then turns 90 degrees and is drilled horizontally.
The show well is drilled deeper but parallel to the injection well. Steam is then pushed through the injection well, which heats the bitumen.
The liquified bitumen then starts to sink into the production well because of gravity. Once in the show well, the bitumen is then pumped up to the surface. There can be up to 20 tubes being used during this process. More tubes used mean less surface disruption.
CSS is very similar to SAGD. There is one tube drilled into the Earth. It is drilled vertically, then turned 90 degrees, and drilled horizontally.
The tube then gets steam pumped into it, which melts the bitumen. The liquified bitumen is then pumped to the surface in the same tube.
Offshore Oil Extraction
Offshore oil extraction is time-consuming and very expensive. It starts with an exploratory process. The first step is to look at the geological and geophysical data, showing potential oil reservoirs.
Then a company will do a seismic survey. This survey maps different geological structures under the seabed.
An exploratory drill will happen if one or more of these structures looks to contain oil. Before the exploratory drill happens, a company needs to get approval from regulatory bodies in that area. After all of that, if the company wants to continue, the development of the mining site starts.
Depending on the size of the project, this step can take up to 10 years to complete. After the area is developed, production can begin.
Oil can be upgraded and refined into synthetic crude oil no matter the process used. There are two ways to do this.
The company uses a combination of pressure and chemicals to break down the sand oil. The process typically adds hydrogen and removes carbon. This refined oil is then used to make gas, jet fuel, diesel, and heating oil.
There are three ways to extract natural gas from the Earth; vertical drilling, horizontal drilling, and hydraulic fracturing.
Vertical drilling was the first process created to extract natural gas from the Earth.
Today this form of drilling is used when the natural gas is directly below the Earth’s surface, and a well is drilled straight down into the rock that holds the natural gas.
Horizontal drilling started in Texas in the 1980s as a way to extract natural gas that was previously impossible to get to.
This type of drilling starts by drilling vertically into the ground. Then the flexible drilling pipe is steered horizontally to the natural gas reservoir.
Hydraulic Fracturing (Fracking)
Hydraulic fracturing (fracking) is a controversial way of extracting natural gas from the Earth.
The process uses water, chemicals, and sand. Those three materials are blasted into a rock formation under the Earth. The sand then props up the rock so that gas can escape. The gas that escapes is then collected for processing.
There are many downsides to fracking which is what makes the process controversial. One downside in the process is it requires large amounts of water, which can negatively impact aquatic habitats and the area’s water table.
The method also produces toxic and typically radioactive wastewater that could drain into other water sources. These sources could be used for drinking, hygiene, industrial or agricultural processes.
Fracking can also cause small earthquakes. For the most part, these earthquakes are too small to be felt on the surface. However, scientists believe they could cause structural damage to buildings and damage to underground pipe networks.