The Supply Chain

Geologists locate oil sources

You put Petrol and Diesel in your car

Exploration

Fuel is made from a substance called Crude Oil. The most widely held theory is that Crude oil is created by dead ancient creatures decaying into the earth’s sedimentary layers. The decomposed animals are then compressed in the earth’s layers over millions of years which eventually turns them into natural gas and Crude oil.

Overall for oil to develop crude oil needs:

• A large amount of decaying sea creatures and plants.
• A porous reservoir rock.
• A layer of impermeable rock to stop the oil escaping.
• Millions of years.

As oil is created deep in the earth’s crust it is difficult to find. Because of this, countries employ geologists to try and decipher where oil can be found. Geologists undergo huge exploration projects and use their knowledge of the structure of rocks, satellite images, gravity meters, seismology and other technologies to find oil sources.

Seismology is the most common form of oil exploration and uses shock waves which reflect back and indicate whether or not oil is present.

To show where oil has been found, geologists use GPS co-ordinates on land and marker buoys in water to mark oil locations. Once this has been done, drills or oil rig systems are set up to extract the oil from the earth.

Drilling Oil

Oil is commonly found out at sea but it can also be found on land. It occurs miles beneath the earth’s service and huge drilling devices are needed to remove the oil from the ground.

How is oil extracted from the earth?

To extract oil from the earth, a drilling system is needed. A rotary drill rig initially makes a hole thousands of metres deep. Steel piping is then placed into the ground and surrounded by a cement shield. Fractures are made at the crude oil level for oil to enter.

A pumping unit is then put in place of the rotary drill rig to keep the crude oil flowing. The pumping unit is turned on long enough to start the syphoning effect of the oil but turned off when the oil starts travelling under the pressure. The reason the pumping unit is turned off is to save energy and money when it is not needed.

How is oil extracted from a place that cannot be drilled?

Oil can be found anywhere, regardless of what is above it. Therefore, oil may occur directly below environmentally protected areas or important structures which prevent activity such as drilling taking place. To get around this issue, drills can now drill directionally if drilling straight down is not permitted. Therefore drilling does not have to happen directly above the crude oil location.

What are the problems of drilling for oil?

The main problem that may occur during drilling is explosions. During drilling there is always the risk of an explosion due to the immense heat involved in the drilling process and possible gasses which could be emitted during the process. Oil rigs do everything they can to avoid explosions occurring.

In 2010, there was an explosion on a BP oil rig in the Gulf of Mexico, the incident was called the Deepwater Horizon disaster. Not only did the explosion kill 11 rig workers, it also leaked oil into the ocean which had a disastrous impact on the surrounding environment and is considered one of the worst environmental disasters in US history.

Oil spills are a constant issue and happen on too many occasions. Therefore drilling, especially offshore drilling, can pose a big risk to both both human life and our environment.

How is crude oil turned into petrol or diesel?

Crude oil is turned into petrol and diesel using the process of refining which separates the products from the oil.

Refining

To change crude oil into usable products such as fuel, it needs to be refined. To refine crude oil you need to separate the hydrocarbons which break down into different chemicals. You can separate the hydrocarbons using a scientific reaction called “cracking”. To “crack” the oil a system called fractional distillation is used which boils the crude oil product. As the substances in crude oil have different boiling points, the system evaporates the crude oil and condenses the vapours at different temperatures and syphons them off at different points. Petrol and Diesel are 2 products which are syphoned off during the process.

After this process, additives and dyes are added to the petrol and diesel substance to make them legally usable fuels. The petrol and diesel is then sent to distribution centres before being transported by tankers to local service stations. This whole process of producing fuel is known as the supply chain.

Bi-products of crude oil

During the refining process, it is not just petrol and diesel which are separated from the crude oil substance. There are also a selection of other bi-products which are created. A bi-product is an additional product created during a chemical process. Bi-products which occur as a result of refining oil to make petrol and diesel are:

Liquid Petroleum Gas (LPG)

Use: As a heating fuel in vehicles and heating appliances.

Description: Clear Gas.

Naphtha

Use: Chemical production.

Description: Colourless liquid.

Kerosene

Use: Jet engine aircraft fuel.

Description: Clear liquid often dyed blue or kept in a blue container.

Lubricating oils.

Use: Lubrication for moving parts.

Description: Brownish coloured liquid.

Parrafin wax

Use: Candles, beauty products and crayons.

Description: A white waxy solid.

Asphalt

Use: Road Construction.

Description: Sticky and black liquid or semi-solid. Also known as bitumen.

Petroleum coke

Use: Fuel.

Description: Grey stones.

Fuel oil

Use: Fuel for ships and power stations.

Description: Dark liquid.

All bi-products of crude oil have a use and are sold on to make the products listed above. As you can see crude oil is hugely useful and as oil resources diminish and the price of oil increases, the human race will have to find alternatives for all of these products.