Heavy crude is a type of crude oil that is thicker, denser, and more viscous than conventional light crude oil. It has a higher molecular weight and contains a larger proportion of heavier hydrocarbons, making it more difficult and costly to extract, transport, and refine. Heavy crude typically has a higher density and lower API gravity (American Petroleum Institute gravity), which is a measure of how light or heavy a petroleum liquid is compared to water. A lower API gravity means the oil is denser and heavier.
Heavy crude isn’t defined by a single molecule or a specific "molecule number," it’s a complex mixture of hydrocarbons with varying molecular weights, typically characterized by high viscosity and density compared to light crude oil. Heavy crude generally contains hydrocarbons with carbon chains ranging from C20 to C50 or more, often including large amounts of asphaltenes, resins, and other heavy compounds. The exact composition depends on the source of the oil.
Heavy crude is a significant energy resource, as it is abundant, especially in places where light crude reserves are declining. However, due to its challenges, production is often more expensive and has a larger environmental impact.
