About Oil and Gas Deposits

Updated on 12.19.2025

15 min read

Middle School High School

Physics - chemistry Life and earth sciences

Hydrocarbons, such as oil and natural gas, are the result of a complex geological process that spans millions of years. This educational resource, aligned with high school science curricula, explores three key stages: the formation of hydrocarbons from organic matter, their migration through rock, and their trapping in geological structures that enable the extraction of deposits.

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 ...

Explore more

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

Analysis of aerial images to study the geology surrounding a hydrocarbon deposit.

From Traps to Commercial Deposits

Commercial oil and gas deposits occupy closed spaces created by deformations in geological layers. These spaces, known as traps, must be large enough to make developing the deposit economically viable.

Learn more