A hydrocarbon deposit can also be referred to as a fossil fuel reservoir, oil reserve or natural gas field. These synonyms describe various types of underground or underwater formations where hydrocarbons, such as oil and gas, are trapped in rock pores or fractures. Other synonyms for hydrocarbon deposits include crude oil deposit, petroleum reservoir and gas condensate field. Each of these synonyms may have a slightly different connotation depending on the composition, location and accessibility of the deposit. However, they all share the common characteristic of being a valuable energy source that is extracted through drilling and production processes.