Crude oil is a naturally occurring liquid mixture of hyfrogen and carbon atoms, referred to as hydrocarbons. These hydrocarbons are found in underground reservoirs within sedimentary rocks formed over millions of years, and are often mixed with natural gas, carbon dioxide, saltwater, sulphur and/or sand, which are seperated from the liquid once extracted.
Gravity/Quality
Light Oil: Flows easily through wells and pipelines and can be refined into a large quantity of transportation fuels (gasoline, diesel, jet fuel).
Heavy Oil: Very carbon rich and requires additional pumping in order to flow through wells and pipelines and required complex refining.
Bitumen: A semi-solid hydrocarbon mixture with the largest deposits located in the Canadian oil sands. Extra heavy oil.
Synthetic crude: produced by upgrading heavy oil into a synthetic light oil misture through the addition of hydrogen or the removal of carbon.
Sulfur Content
Sweet: low sulfur content
Sour: heavy sulfur content
Benchmarks
WTI West TexasIntermediate – Most widely used benchmark is a light/sweet crude oil.
WTS West TexasSour – Common benchmark for sour crude.
Brent – Most widely used international benchmark is a light/sweet crude produced in Europe.
Tapis – Common benchmark used in the Asia Pacific region is a light/sweet crude inAsia.