The How Why and How Much of Oil

This is a barrel of crude oil. It holds about 42 U.S. gallons or about 159 liters. Each day, the world consumes 88 million of them. 19 million of which are used right here in the U.S. of A. For 150 years now, we've been living in a petroleum world. Most experts agree... ...that over time, humans have consumed more than 1 trillion barrels of oil. How much recoverable oil is left in the ground is a subject of great debate among energy experts, but... ...rough estimates suggest that the number is between two and four trillion barrels. But, in order for those two to four trillion barrels of oil to be of any use to us, we first need to find it and second, get it out of the ground. Neither of those things are easy, and they're getting more difficult. Fossil fuels...whether you love them or you hate them, you use them. Like a whole ton of them, in fact. You're using them right now to keep your lights on and to watch me on your computer. So, you might as well understand how we find it, how we get it, and how much we have left. Otherwise, you might just be left in the dark. Before we deal with the "how" part of petroleum science, we should probably first ask how much because how much oil we think or fear is left is influencing how and where we're looking for it. This brings us to a little thing called "peak oil." Peak oil is the point at which we have reached the maximum rate of global oil production. This idea was first formulated in 1956 by Shell Oil employee M. King Hubbert, who correctly predicted that oil production in the U.S. would reach its peak around 1970. He theorized that it takes about 40 years from the peak oil discovery in a given country to reach peak rate of prodution. In the US, discovery peaked in the early 1930s, but on a global scale, oil discovery peaked in the 1960s. Which is why since early 2000s people have been freaking out about the idea that humanity may never produce as much oil as it does today obviously we're dealing with a finite resource here so there will come a day when it will run out but Hubbard theory of peak oil has proven incorrect on a worldwide scale mostly because he didn't foresee the enormous changes and how we discover and extract oil today we're finding oil and places we never thought existed and in areas thought to have dried up long ago and we're extracting it using methods and technologies that weren't around when your parents were your age to understand the science of the you gotta go back maybe like a couple hundred million years oil and natural gas are formed by the breakdown of organic materials under really high pressure and temperature in sedimentary rock most of the material came from the remains of zoo plankton and algae that lived in the oceans between ten and six hundred million years ago when they died their carbon-rich bodies sink to the bottom of the ocean as they decayed in deeper and deeper layers of oxygen starved sedimentary rock the heat and pressure eventually distilled the biomass into either oil or gas and what we're really after in these substances are their key ingredients called hydrocarbons like the name tells you these compounds like methane ethane propane and so on contain only hydrogen and carbon and when they're burned in the presence of oxygen they give off lots of heat over time the liquid version of this hydrocarbon mixture petroleum migrates up into porous layers of rock usually limestone sandstone this is where most oil and gas becomes trapped thanks to impermeable layers of rock like granite or marble above it when we talk about conventional met of extracting oil we of course mean drilling and for formation to be worth drilling it needs to have at least a couple of qualities one is enough permeability that is the ability for a fluid to pass through it to allow the oil to flow easily into a well it also has to have enough open spaces in the rock to hold fluid which is called its porosity now the reality is most of the big easy deposits with these traits that we know about the low-hanging fruit of the petroleum world have been discovered and exploited finding new ones requires better equipment and more money and yes more energy on whether it's improved a lot in recent years as the use of instruments called gray visitors to measure tiny changes in the Earth's gravitational field sedimentary rocks usually get denser and therefore have stronger gravity the farther down you go but folds her faults in the rocks can create big pockets of lower density that could be where oil is hanging out with visitors can find those pockets which helps exploration crews near their searches geologists also often use magnetometers to detect tiny changes in the Earth's magnetic field because it turns out the magnetic field to changes when oils around where oil and gas are deposited rocks are less magnetic than the surrounding Rock so through aerial surveys magnetometers can detect some of these weak spots to give oil prospectors some promising leads the most common method of finding oil however is through seismology by creating shock waves and measuring how fast they travel through layers of rock geologists can gauge their density it's like the same concept as an ultrasound scan at your doctor's officer and echo sounder used by ships online seismic waves are generated using explosives or specially designed vehicle known as a vibro size or thumper trucks the trucks use what's called a seismic vibrator that's gonna let that phrase sink in for a second to create a shock wave on the ground when using explosives geologist big bore holes up to 25 meters deep and detonate a small charge in both cases detector is called geo phones are used to measure the shockwaves oil hunters can use this technology under water as well in that case scientists use compressed air guns on a boat instead of giant vibrators to create the sound ways the sound waves penetrate the layers of rock below the seabed and a reflected back now all these methods are great at finding rock formations with enough permeability and porosity to hold oil but with demand always rising and peak oil fears we started going hard after the unconventional stuff experts call them tight oil and heavy oil heavy oil is oil that's as dense or denser than water usually oils a lot less dense than water which is why it floats on top of water tight oil meanwhile is found in formation where the rocks porosity and permeability are really really low there's oil in there but it's not flowing like the easier places we used to drill here in the US tight oil is the reason crude oil production grew by more than 1 million barrels a day in 2012 the largest increase in our country's history the two largest tidal formation is the eagle ford in South Texas and the Bakken in North Dakota and Montana contain up to 700 billion barrels seven hundred billion barrels of oil but only about one to two percent of that is recoverable the oil in these places is so tightly trapped in sandstone that conventional vertical wells proved worthless at extracting it but in the last 10 or 15 years engineers have figured out a few ways to get at it one way is horizontal drilling instead of just digging a well straight into a deposit like a straw this method starts vertically and then angles to approach from the side running the length of the reservoir in order to maximize the wells exposure to the trapped oil engineers have also discovered that if you create fissures in the rock by injecting a combination of water sand and chemicals at extremely high pressure oil will see through the cracks and can be extracted through the horizontal pipes this is Method number two and you know it is fracking heavy oil is an entirely different beast the oil sands of Canada in Venezuela have dramatically altered predictions about how much usable oil we have left in the world Alberta's oil sands may contain between 1.7 and 2.5 trillion barrels of oil of which maybe fifteen percent is recoverable that still amounts to about 75% of the petroleum reserves in north america also called tar sands or bituminous sands oil sands are a mixture of sand water clay and bitumen a thick mixture of hydrocarbons found in crude petroleum but human is so thick that it basically is a semi-solid with the consistency of molasses scientists aren't sure how these enormous deposits came to be some think that they're remnants of crude oil reservoirs that were destroyed microbiologically leaving the human behind others think that underground pressure for stood up from shale deposits were hydrocarbons soaked in the sediments and sand on the surface either way since between makes up between one and twenty percent of these oil sands conventional extraction methods just don't work it would be like trying to drink up the world's absolutely thickest milkshake through a crazy skinny straw so instead of oil companies just attack it at the surface a lot like how some minerals are mind some of the largest excavators and trucks you have everything in your life are used to scrape away topsoil and dig out the underlying tar sands the mixture is then steamed to extracting bitumen soil and pipe to refineries but only twenty percent of the tar sands can be mined like this the rest is too deep in the ground to get that stuff oil companies often use a process called steam assisted gravity drainage it involves drilling to horizontal wells one near the bottom of the reservoir and the other a few metres above it steam is injected into the upper well to loosen up the bitumen which then flows into the second well where it can be drawn up now you probably notice that whether we're talking about conventional or unconventional oil finding it is usually pretty freakin complicated and the harder it gets for us to find the oil the more were pushing the limits of what machines can do and what engineers can dream up so it's worth noting the extra effort and energy that's now required to extract the black gold from the ground at some point probably in your lifetime the cost of extracting oil will get so high that it will no longer be economically viable for either the producer or the consumer to use it at least in the ways that we currently use it which is pretty wasteful and so everyone knows that it's time to start exploring alternative energy sources that don't require squeezing oil out of sand thank you for watching this episode of scishow if you have any questions or comments for us you can find us on Facebook or Twitter or force down in the comments below and if you want to continue getting started with us here at scishow you go to youtube.com / - oh and subscribe yeah

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