Definition - What does Viscous Oil mean?
Viscous Oil is heavy or extra heavy crude oil with high viscosity. Oil Viscosity helps to measure a fluid's resistance to flow. If the oil contains higher viscosity (thickness), it does not flow easily under normal conditions. Viscosity in oil relates to its informal approach of thickness. Oil is termed as viscous, if its viscosity is higher than water and mobile if its viscosity is less than water. Any fluid with very high viscosity may appear as a solid.
Petropedia explains Viscous Oil
High viscosity and high specific-gravity oil is known as Viscous Oil. The American Petroleum Institute (API) explains oil as viscous if its gravity is less than 22.3° API. Along with high specific-gravity and high viscosity, the Viscous Oil also has high asphaltene, nitrogen, sulfur, low hydrogen to carbon ratios, high acid numbers and heavy metal content as well. The viscosity of the oil can be measured with Kinematic viscosity unit. Kinematic Viscosity calculates the resistance of a fluid to flow. The internal resistance of a fluid to flow can be calculated as Absolute or Dynamic viscosity.