Viscous Crude Oil
Crude oil's viscosity can vary from a low viscosity liquid to up to tar-like, nearly solid form. Classification according to the API degree: ... Medium crude oil: API gravity from 31.1 °API to 22.3 °API (870 to 920 kg/m3) Heavy crude oil: API gravity from 22.3 °API to 10 °API (920 to 1000 kg/m3).
