Does anyone know the difference between light oil and heavy oil when your drilling?

When I was researching oil companies I came across the terms light oil and heavy oil.Does anyone know the difference between light oil and heavy oil when your drilling?
Every oil is a different mixture of hydrocarbons usually with the general molecular formulae CnH(2n-2), CnH2n, and CnH(2n+2). Under normal conditions the C1 to C5 components are gases, C6 to about C20 are liquids, and the higher ones are tars or waxes.





If most of the hydrocarbons are C6 to C8 liquids, with plenty of dissolved gases, it is a ';light oil';.





If most of the liquids are C9 and upwards, with not much dissolved gas, it is a heavier oil. The terms are relative.





The specific gravity of the oil relative to water varies fairly smoothly from about 0.68 up to 1.05 with the average C number of the components, but not linearly.Does anyone know the difference between light oil and heavy oil when your drilling?
Light oils are more valuable. Their light components correspond to motor fuel and aviation fuel, and the gas is always saleable - C1 and C2 gases as domestic gas, C3 and C4 as bottled gas. Heavy oils need more processing for use as diesel or heating oils. Report Abuse

Light crude oil is crude oil with a low wax content. The clear cut definition of 'light' and 'heavy' crude is hard to find, simply because the classification so made is based more on practical grounds than theoretical. Since crudes with high viscosities are more difficult to transport/pump, those with apparently lighter wax content are referred to as 'light crude' and the ones with substantially more wax are classified as 'heavy crude'.


http://en.wikipedia.org/wiki/Light_crude鈥?/a>


http://en.wikipedia.org/wiki/Heavy_crude鈥?/a>


Hope this helps
This is my educated guess: A product with a lower specific gravity would 'float' on one with a higher s.g. (i.e. oil floats on water). I believe oils have different specific gravities. Perhaps the difference is because of that.