1. n. [Geology]

Naturally occurring, inflammable organic matter formed from kerogen in the process of petroleum generation that is soluble in carbon bisulfide. Bitumen includes hydrocarbons such as asphalt and mineral wax. Typically solid or nearly so, brown or black, bitumen has a distinctive petroliferous odor. Laboratory dissolution with organic solvents allows determination of the amount of bitumen in samples, an assessment of source rock richness.

See: asphalt,  generation,  geochemistry,  hydrocarbon,  kerogen,  petroleum,  petroleum system,  source rock,  tar sand

2. n. [Heavy Oil]

A designation for a hydrocarbon fluid with a gravity of 10° API or lower, based upon the classification of the US Department of Energy.

Synonyms: ultraheavy oil

3. n. [Shale Gas]

The fraction of naturally occurring, inflammable organic matter that is extractable from rock using organic solvents. Many petroleum precursors are composed of bitumen, but most are formed from kerogen in the process of petroleum generation. Bitumen includes hydrocarbons such as asphalt and mineral wax. Typically solid or nearly so, brown or black, bitumen has a distinctive petroliferous odor. Laboratory dissolution with organic solvents allows determination of the amount of bitumen in samples, an assessment of source rock richness. Burial and heating of kerogen yield bitumen, then liquid hydrocarbons, and then hydrocarbon gas. Understanding organic content is especially important in shale reservoirs because the shale is both the source rock and the reservoir rock in the petroleum system.