Many people buy petroleum each day and spend hours of driving but don’t often think about where it actually came from. In addition, we don’t often think about how it is made from crude oil and produced from the refinery before they are brought into service stations.
It actually takes thousands to millions of years for the molecule of oils to form. The remains of creatures which existed millions and millions of years ago change chemically and they compress into sedimentary rocks.
Over time, the pressure coming from the ocean or sea as well as the transferring of sand and silt turns those layer of sediments to further compress. Also, the chemical changes that take place also increase, turning the remains of creates into hydrogen and carbon compound. Keep in mind that this process takes so many years and it is reliant on heat, time and pressure.
Then, hydrogen and carbon atoms start to change in composition and provided all the proper ingredients such as changes in the movement of the earth, the change in the type of rock and the rock movements itself.
Surveyors are using a series of tests that would determine where the oil may be deposited in the sedimentary rock areas. This is very essential in any rock formed over time composed of sediment. Then these surveyors are using specific tests such as the reservoir rock, source rock, cap rock and the right sequence of geologic events. And after than, they will identify how long the organic materials have been trapped into the rocks and allow the formation of hydrocarbons.
If the survey has already started, the surveyors as well as producers of petrol will look for the potentiality that the right hydrocarbons are in place before the digging can start. In drill sites that are off-shore, when the drilling starts, the pumps are used in the extraction of oil and gas, then pump them into the reservoir. As soon as the oil and gas hit the pumps, they will bubble and will be separated.
The reservoir containing the oil will be moved by pipeline back into the mainland refinery.