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
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