To decode the science of crude oil formation we first need to go back in time. Waaaay back! We have to set our geologic clocks back tens and even hundreds of millions of years to a time when ancient seas covered much of North America. Small lifeforms, mostly algae, and tiny creatures known as zooplankton lived in these ancient seas. They produced their life energy by using CO2, water, and sunlight. Like all living things, these plants and animals eventually died. Their remains fell to the bottom and mixed with and were buried by sediment. Their remains and seafloor sediment piled up for millions of years.
Eventually, the pressure from the piled sediment and heat caused changes in the plant and animal, or organic, materials into a wax-like material called kerogen. Another by-product of this pressure is a tar-like substance known as bitumen, which we will learn more about later.
Catagenesis happens next. Big word. Essentially, catagenesis is the cracking of kerogen into smaller, hydrocarbon molecules that make up crude oil. Hydrocarbons are carbon atoms that have their “outer shell” filled only with hydrogen atoms. The minerals contained in the plant and animal remains mentioned earlier have an important role in catagenesis. They function as catalysts, materials that speed up or change the outcome of a reaction without being used up in the reaction itself. The catalyst helps catagenesis continue and, if the levels of pressure and temperature are just right, it forms crude oil – ta-da!
When you’re ready to drill even deeper into the science of crude, click on the “Learn More” tab below to discover more about the mysteries of crude oil formation and exploration. Filling up your gas tank will never be the same again.
Plus, take a moment and check out the jazzed petroleum industry careers video on the right. Then, click the link of our educational partner here to dig even deeper into the science of refining and transporting crude oil.