Where are oil and gas found?
Oil and gas are found in geological basins that have been filled over tens of millions of years by fragmented material.
This material has hardened into sediments, or layers of rocks such as sandstones, shales and coals.
Organic material (mostly plankton and algae) in these rock layers breaks down to hydrocarbons (oil and gas) that are trapped in the rocks.
Australia produces most of its oil and gas from sedimentary basins in northern South Australia, inland Queensland, Bass Strait, offshore Western Australia and the Timor Sea. But there is also some production in onshore Western Australia, NSW and the Northern Territory.