Light Crude oil is liquid
petroleum that has low density and that flows
freely at room temperature. It has low
viscosity, low specific gravity and high API
gravity due to the presence of a high proportion
of light hydrocarbon fractions. It generally has
a low wax content as well. On the other hand,
heavy crude oil or extra heavy crude oil is any
type of crude oil which does not flow easily. It
is referred to as “heavy” because its density or
specific gravity is higher than that of light
crude oil. Heavy crude oil has been defined as
any liquid petroleum with an API gravity less
than 20°. Extra heavy oil is defined with API
gravity below 10.0 °API (API gravity, is a
measure of how heavy or light a petroleum liquid
is compared to water. If its API gravity is
greater than 10, it is lighter and floats on
water; if less than 10, it is heavier and
sinks).
Light crude oil receives a higher price than
heavy crude oil on commodity markets because it
produces a higher percentage of gasoline and
diesel fuel when converted into products by an
oil refinery. Heavy crude oil has more negative
impact on the environment than its light
counterpart since its refinement requires the
use of more advanced techniques an the use of
contaminants.