Petroleum Chemistry
Petroleum comes from many different substances, such as oil and natural gas, from which various products are derived, such as: gasoline, kerosene propane, fuel oil, lubricating oil, wax, and asphalt. These substances are mainly compounds of only two elements: carbon (C) and hydrogen (H). They are called, therefore: hydrocarbons.
The specific study of petroleum is referred to as petroleum geochemistry. Understanding petroleum geochemistry is critical in the exploration and development of petroleum.
Links
Organic Chemistry and Hydrocarbons by Purdue University: a great web-based primer on organic chemistry, with specific pages that reference hydrocarbons