Oil and Gas Formation (more...)
In the Queen Charlotte Basin, all of the necessary ingredients exist
for oil and gas formation. Source rocks containing organic matter must
undergo sufficient burial and heating to transform the kerogen (the starting
material) into hydrocarbons (oil and/or gas).
Some common terminology:
| Organic Matter |
- the remains of dead plants, small marine organisms
and bacteria that are the starting ingredients that make up oil and
gas
|
| Kerogen |
- what organic matter turns into after burial under more sediments
and some chemical alteration
|
Geothermal Gradient |
- going deeper within the earth, temperatures get hotter and hotter |
| |
- around 30°C/km
|
|
- as kerogen gets buried, its temperature increases
|
So where does oil and gas actually come from?
| The Formation and Accumulation of Oil and Gas |
- given time (millions of years) and enough heat (usually
at least 100°C), kerogen begins to change into oil
- as temperatures continue to increase, the oil becomes gas
- oil and gas migrate out of the kerogen-containing source rocks
and into porous and permeable surrounding rocks (rocks with microscopic
pores and cracks) where the pressure is lower |
|
- oil and gas get trapped when they come up against a rock through
which they cannot migrate
|
Further Details
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