Sediment layer Created over millions of years
Sediment layers are created when particles such as sand or dead organisms are sedimented on land or in the sea to form a single layer. Sediment layers play a special role in the search for crude oil and natural gas: the sludge sedimented on the ground, from which the hydrocarbons are later formed, is slowly covered by sediment. The hydrocarbons gather ad flow in the pores of the surrounding rock until they encounter an impermeable sediment layer. That is how a crude oil or natural gas reservoir is created.