Question

How is oil made in our earth?

Answer 1

Hint: Oil is formed deep inside the earth’s crust below the oceans due to the immense pressure of the overlying layers and the high temperature from the mantle. Generally, this formation takes place in the lower mantle and the oil is found at the upper mantle.

Complete answer:
The formation of oil under the Earth’s surface is a long process which is a slow process as well. The dead and organic matter is trapped down under the Earth's surface which is then subdued under the layers of the earth over time due to the formation of sedimentary rocks. When this depth reaches about 4 to 6 kilometers under the Earth, the pressure becomes appropriate for the formation of oil and natural gas. However, this alone does not form oil under the Earth’s surface.

The temperature range of 90 degrees celsius to 150 degrees celsius is essential for the formation of oil. Mostly the oil is formed around the shale oil type rocks and then it escapes from the openings available or through the holes drilled in the Earth by the humans from time to time. The transition takes place from organic material into kerogen and then into oil and natural gas.

Note: Oil and Natural gas is not found in the land areas due to lesser concentration of shale but coal is abundant on land. Petroleum is mostly found in the oceans but there are huge reserves of petroleum on the land as well which are known as onshore oil fields.