Formation of Crude Oil

Petroleum is formed under the earth’s surface by the decomposition of marine organisms, the remains of tiny organisms that lived in the sea, and to a lesser extent, those of land organisms that are carried down to the sea in rivers, and of plants that grow on the ocean bottom.

Over time, they are enmeshed/covered with fine sands and silts that settle to the bottom in the quiet sea basins.

Over millions of years, the remains are buried deeper and deeper. Deep beneath the Earth, heat and pressure are extremely high. The enormous heat and pressure turn them into crude oil.

Such deposits, which are rich in organic materials, became the sources of rock for the generation of crude oil. Once the petroleum forms, it flows upwards in the earth’s crust because it has a lower densityDensity is the measurement of how tightly a material is packed together i.e. how closely the particles are packed in the material. The tighter the material is packed the more its... More than that of water.