Advantages:
1.Highly compact portable source of energy used for most forms of mechanical transportation.
2.Excellent source of organic molecules for building plastics,medicines, rubber, fiber, etc.
3.Can withstand high heats without breakdown making it useful as lubricants like motor oil and grease
4.Residuals make excellent surface for asphalt roads and waterproof roofing materials
5.Certain components make excellent solvents for paint, industrial use etc.
6.Other components (propane, butane) make excellent compact source of portable cooking fuel and heating in areas that do not have infrastructure for natural gas delivery.
7.Natural gas is used to make fertilizers used in agriculture and household detergents
8.Compared to most other fuel sources it is still one of the most economical -in other words the costs to produce it are relatively cheap compared to other energy sources.
9.Production of oil has much less impact and a smaller footprint on the earth surface than production of coal from strip mining
10.If not for the discovery of oil, all whales would likely be extinct, because they were the primary source of lamp oil for lighting before oil, and are still recovering from hunting in the 1800's.
11. The oil industry has been a source of much advanced technology and many new products that have changed our lives for the better.
12. During WW2 oil produced in Texas was the major source of fuel supply for the Allied Forces and without that advantage over both the Germans and Japanese, the world might look very different today. At that time the US was the major supplier of oil in the world.
13. Natural gas wells are the world's supply of helium gas.
14. Oil refining produces the world's supply of elemental sulphur as a byproduct, used for many industrial applications.
Disadvantages:
1.Oil is a carbon based fuel and the primary way it is used is to burn it, releasing more than its weight in CO2 because of the added oxygen. CO2 is a greenhouse gas and is expected by most scientists to be a cause of global warming.
2.We are running out. Estimates vary from 50 to 150 years before we run out of oil. This is impossible to predict, but most major oil companies have been failing to discover new reserves equal to the amount of oil they are producing for the last few years.
3.Much of the remaining oil in the world is in politically unstable areas including Africa, Middle East, Russia, and parts of Southeast Asia.
4. Wars get fought over oil, and wars are won with oil (WW2) so it can be a very negative influence on relations between nations.
5. Oil must be transported in ever increasing quantities. Pipelines are one common method but where no pipeline exists oil can become 'stranded', in other words there is no way to get it to market. The natural gas in northern Alaska is a good example of this since there is no gas pipeline the oil companies must pump natural gas back into the wells.
6.The other transport problem with oil is from the inherent dangers of supertankers. Oil spills do serious environmental damage that takes decades to recover from. While oil spills do occur naturally, and have over time, the effects are often catastrophic for the area affected. Oil does break down naturally from biological and chemical decay, but it takes time.
7. Our consumption of oil is increasing at the same time our production is falling. The world is currently consuming 83 million barrels of oil per day. We aren't producing that much.
8. Many oil producing areas are subject to severe weather and this can interupt production. Last year's hurricanes are an example. Production will not be restored until well into this year.
9. Oil does contain some cancer causing compounds, benzene is one of those.
10. Volatile components of oil and natural gas can contribute to smog.
11. Some additives put into gasoline to improve its smog fighting qualities have leaked out of underground tanks at gas stations and polluted ground water with hazardous chemicals. This type of pollution is very hard to remove.
12. Drilling for oil is getting more difficult and expensive because we are now drilling as deep or deeper than 20,000 feet to find new reserves.
13. Because of the price cyclicity in the oil industry the industry is discovering that it may soon have a serious shortage of trained workers. The average age in the industry is about 50 years old. New entrants are not coming into the field for several reasons. The oil industry is going to be challenged to keep producing at the current rate with fewer employees available.
14. Some oil is now being strip mined in the form of tar sands. This will be very hard to restore these areas.
15. Sulphur in oil ends up in refined fuels and contributes to air pollution.