Turns out it's all light hydrocarbons.

They can also combine molecules of the lightest hydrocarbons into heavier molecules.

During this process, oil sand is moved through a rotating drum, cracking the bitumen with heat and producing lighter hydrocarbons.

Also, it is a source of light aromatic hydrocarbons for the chemical synthesis industry.

Additional cracking can create the lighter hydrocarbons used in gasoline.

Most tetrachloroethene is produced by high temperature chlorinolysis of light hydrocarbons.

Lower levels of light hydrocarbons to cut down on gasoline evaporation.

The company began mixing this very light hydrocarbon with heavy oil, enabling it to flow more easily.

It happened to include a considerable amount of elemental sulfur, pitch, and light hydrocarbons.

You can show how 'light' hydrocarbons are gases at room conditions, but 'heavy' ones are liquids (or even solids).