Definition - What does Oil Viscosity mean?
Oil Viscosity refers to the thickness of oil. It is one of the most important properties of oil. In scientific terms, Oil Viscosity can be defined as the amount of resistance exerted by oil until it gradually deforms due to shear stress. During the analysis of oil in labs, its viscosity is often the very first parameter which is measured. Oil Viscosity is inversely proportional to the API gravity, e.g., viscous crude is heavy thick crude with an API gravity of less than 10 degrees and flows at a very low speed in a pipeline or a wellbore.
Petropedia explains Oil Viscosity
The viscosity of oil occurs when the molecules of the oil collide with neighboring molecules moving at different velocities. Viscosity plays a very important role in deciding the price of crude oil as well as petroleum products. Oil Viscosity is inversely proportional to API gravity which means that if the API gravity of crude oil is high, it will have a lower viscosity and if the API gravity of crude oil is low, its viscosity is high. Highly viscous oil is heavy, sticky and demands more costly processes in its transportation and refining, whereas low viscous oil is light and moves swiftly from reservoir to the surface and then into pipelines.
The following are the factors which affect Oil Viscosity:
- The composition of oil.
- Impurities and dissolved gas.
- Atmospheric conditions such as temperature and pressure at which oil is produced or transported.