Transcript Creation of Oil & Natural Gas

Where do we find oil?
In sedimentary rocks originally located between
7500 and 15,000 feet underground, for a long
period of time.
We start with organic material (dead plants
and animals) that accumulates and then is
buried under later layers of silt or mud,
underwater.
The layers of organic matter and silt/mud
need to be buried underwater and then
underground for millions of years.
This rock must then be buried underground
between 7,500 and 15,000 feet for a
combination of heat and pressure to
transform the organic matter to oil
molecules.
Below 15,000, underground heat breaks the
organic matter (and any oil) into natural gas.
Above 7,500 and the rock hasn’t been squeezed
and heated enough to break down the
organic material into oil.
Normally in nature, organic material is
recycled: dead plants, etc. become soil that
new plants use.
Even if the organic material accumulates and is
buried, it may not be buried deep enough to
convert it to oil.
Even if organic material does get buried and
converted into oil, it can then become more
deeply buried and turned into natural gas.
On top of this, the oil rich sedimentary rock can
be pushed upwards, and through a variety
of ways, the oil can leak out of the rock.
The rock also has to have a certain amount of
porosity, (microscopic holes and cracks) so
the oil can flow.
Lastly, the oil-bearing rock has to have a nonporous cap so the oil doesn’t leak out.
So even if geologists do find the right type of
rock, it often doesn’t contain any oil, or
extremely small amounts.