HOW DOES OIL REACH US?

At places where crude oil is found, huge, hollow chisels drill several hundred meters deep in the Earth to reach the rocky layers containing oil. In some cases, the oil shoots out because of the pressure of the natural gas, which is found frequently with crude oil. Pumps are used to bring the oil to the surface if the pressure is not adequate. The oil is then transported to the big harbours with ships or through pipelines- hundreds of kilometers long. Sometimes it is also transported directly to refinery, which it is processed further.

How is oil discovered ?

By using acoustic or sound signals, the geologists identify the place where oil can occur on the Earth. They study these regions by looking in the rocky layers and taking samples at different depths. if  the studies point to a deposit of oil, a hole is drilled in the ground in the hope of finding oil. Scientists believe that crude oil arose from the smallest sea organisms, the planktons. After dying, the planktons sank to the seabed and were covered with sand and sludge over a long period of time. Because of the high pressure exerted by this layer, the dead mass got converted into digested sludge, which gradually got converted into crude oil. Since oil is lighter than rock, it rose up and was held in pores of the rock , like water in a sponge.

How is petrol obtained from crude oil?

Crude oil is a mixture of different substance and must first be 'refined in a refinery- it must be broken down to its components. For this, it is heated at about 300 dC in a distillation set - up. The individual substance evaporate at different temperatures. Petrol, used as  fuel in many cars, becomes gaseous at temperatures between 35 dC and 140 dC, whereas diesel oil becomes gaseous at about 300 d C. The different vapours are collected and cooled or liquefied in this way, the individual components of crude oil are separated from one another and stored as diesel oil, kerosene, or petrol.