About Oil and Gas Deposits

Published on 01.07.2015
Middle School
Life and earth sciences

15 min read

It takes millions of years for oil or gas to form. During this time, the molecules migrate slowly to the surface and are "trapped" in natural reservoirs. 

Explore

How Oil and Gas Deposits Are Formed

Deep in the Earth, oil and natural gas are formed from organic matter from dead plants and animals. These hydrocarbons take millions of years to form under very specific pressure and temperature conditions.

Learn more

How Oil and Gas Migrate

Starting out from the source rock where they are formed, hydrocarbon molecules, which are light, set off on an upward journey to the surface. They accumulate in porous rock and are blocked by impermeable rock, thereby creating oil and gas deposits.

Learn more

The Slow Formation of Oil and Natural Gas Deposits

It takes millions of years for decaying organic matter to be transformed into hydrocarbons within source rock. As sedimentation occurs, chemical reactions create the carbon and hydrogen molecules that make up liquid or gaseous hydrocarbons. The hydrocarbons then slowly travel upwards until they are trapped by impermeable rock and form a deposit in a reservoir.

Learn more