#1503 What is fracking?

What is fracking? Fracking is a method to get natural gas and oil out of shale rocks by fracturing them.

Humans have used oil and natural gas for thousands of years, but we only really began using it on a large scale from the middle of the 19^th century. It was the Industrial Revolution that spurred the quest for oil because it has more energy for the same amount of weight than the coal that was being used to power steam engines. You can get 8 kWh of heat from 1 kg of coal, and you can get 12 kWh of heat from 1 kg of oil. Interestingly, you can get 24,000,000 kWh of heat from 1 kg of uranium-235, but we are not talking about that. Scientists knew that there was more power in oil than coal, but two things made oil more viable. The first was in 1846, when Abraham Gesner worked out how to make kerosene from oil. This became a common method of lighting. The second thing was in 1859, when Edwin Drake worked out how to make a successful deep oil drilling well. Since then, we have improved our oil drilling methods, and we can get it from almost anywhere now.

As we reach the end of 2025, more power is coming from renewable sources, but the fossil fuel companies still want us to use their products. And, to be fair, we do use oil for an awful lot more things than just power. To help with our addiction, they are always on the lookout for new sources of fossil fuels. One of those is fracking. It is very complicated and expensive, but it does open up a new source of oil and natural gas.

Fracking involves getting oil and natural gas out of the bedrock by fracturing it. They can be found in many different types of bedrock, but the most common rock used in fracking is shale. Shale is a sedimentary rock, which means it was set down in layers. Clay, silt, mud, and organic matter sank to the bottom of ancient seas and slowly built up. As the pressure got higher, they were compressed until they formed shale rock. Some of the shale rock was pushed to the surface, but a lot of it is still deep down underground. Because it built up in layers, it trapped a lot of organic material that became fossil fuels, such as oil and gas. Shale is a lot less porous than other sedimentary rocks, such as sandstone and limestone, which means the oil and gas are trapped inside pores within it. Sandstone and limestone are drilled first, and then the oil companies turn to shale.

To get the oil and gas out of shale is a tricky process. The first step is to drill a borehole roughly two kilometers down, varying depending on the depth of the shale. Then a horizontal borehole is drilled from the base of the first borehole, stretching for roughly 3 kilometers. The borehole is then lined with a metal casing that keeps the hole from collapsing, and then a layer of concrete is pumped into the gap around the outside of the casing and the edge of the hole. When the drillers are ready to begin fracking, the casing and the concrete layer are perforated at the area to be fracked. Then, water, sand, lubricating fluids, and other chemicals are pumped down the borehole at extremely high pressure. The water shoots down the pipe and bursts out of it where the casing was perforated. The bedrock the borehole passes through has many natural cracks and veins in it because it was made in layers. The high-pressure water, sand, and chemicals find all of these cracks and rapidly expand them, cracking the rock even more. The cracks open for many meters in every direction. Once enough water has been pumped in, it is turned off, and the sand that was mixed with the water stays behind, preventing the cracks from closing again. The gas and oil escape from these cracks and travel back up the borehole. Roughly 10 million liters of water is used each time. That is the same as 4 Olympic swimming pools. Some operations use even more water. When they are ready to frack another section, the previously perforated part is resealed, and a new hole is made.

There are several problems with fracking. The first is that it is not very efficient. By this, I mean that individual wells dry up very quickly, and the oil companies have to build more wells. They have to constantly drill and build wells to maintain the supply. Also, fracking can cause earth tremors in nearby places. There is also the problem of the water use and all of the chemicals that are used. The water and chemicals are pulled back to the surface and treated, but there is always the risk of drainage into the ground at some point. Another problem is that one of the main gases that fracking releases is methane, and that is far worse for climate change by weight than carbon dioxide. And this is what I learned today.

Sources

https://www.bbc.com/news/articles/c9v73r1ljl0o