List of hydrocarbons with formula

1.1.

Hydrocarbon symbol

The Origin of oil and gas – Organic matter

Petroleum was formed from organic matter. The organic mater was deposited in a marine environment and remained buried under anoxic conditions for 100-400 millions years.

Over the years, layers of silt, sand and other sediments settled over the buried organic matter. The increase of pressure and temperature slowly transformed the organic matter into hydrocarbons (kerogen, oil, gas). Also, over those millions of years various plate tectonics (continents drift over the underlying mantle) and other geological phenomena resulted in the rearrangement of oceans and continents; thus, we encounter oil in both onshore and offshore locations.

The deposition of organic matter took place as:

• Marine organisms (zooplankton and algae) that settled to seabed at depths where oxygen concentration is very low to decompose the organisms.
• Organic mater from nutrient-rich regions such as ancient river deltas.

  Those large amounts of organic material were covered by subsequent sediments faster that decomposition could take place.

Notes

how is hydrocarbon created