Definition: What is a deposit?
A deposit is an area in the earth’s crust where solid or gaseous resources are found in a high natural concentration.
If extraction of the deposit is worthwhile, it is referred to as a workable deposit.
If extraction of the deposit is worthwhile in the future, it is referred to as a usable deposit.
Deposits contain resources such as natural gas, crude oil, coal, ore, salt, stone and other minerals.
Deposits are evaluated on the basis of development, extraction and marketing costs.
Formation of crude oil and natural gas deposits
Crude oil and natural gas are transformed hydrocarbons that accumulate in so-called carrier rock. A crude oil deposit (or natural gas deposit) is formed when crude oil (or natural gas) on the way to the earth’s surface is encapsulated by impermeable layers of rock so it can accumulate accordingly.
Conventional and unconventional deposits
Depending on the possible extraction methods, natural gas and crude oil deposits are classified as conventional or unconventional. While extracting crude oil and natural gas from conventional deposits with permeable layers of rock is relatively straightforward, hydraulic fracturing (fracking) is used on unconventional deposits.
In case of unconventional deposits, crude oil or natural gas has to be flushed out of the rock layers by means of fracking.
Natural gas and crude oil deposits in Germany
There are numerous crude oil and natural gas deposits, especially in northern Germany.
About 20 % of our natural gas demand is covered by extraction from domestic natural gas deposits.