Uses of Petroleum

Petroleum products are used widely in our everyday lives. They are used to power automobiles produce containers and to keep us warm. Petroleum, or crude oil is liquid composed of various organic chemicals. It is found in large quantities below the surface of Earth and is used as a fuel and as a raw material in the chemical industry. The word petroleum comes from the two Latin words “petro” and “leum” “petro” meaning rock and “leum” meaning oil. The chemical composition of all petroleum is principally hydrocarbons which are a family of organic compounds, composed entirely of carbon and hydrogen. Petroleum is formed under Earth’s surface by the decomposition of organisms.

The remains of tiny organisms that live in the sea are trapped with the sands and silts that settle to the bottom in sea basins. These deposits become the source rocks for the generation of crude oil. The process began many millions of years ago with the development of abundant life, and it continues to this day. The sediments grow thicker and sink into the seafloor under their own weight. As additional deposits pile up, the pressure on the ones below increases several thousand times, and the temperature rises by several hundred degrees. The mud and sand harden into shale and sandstone and the remains of the dead organisms are transformed into crude oil and natural gas. Surface deposits of crude oil have been known to humans for thousands of years. In the areas where they occurred, they were long used for limited purposes, such as caulking boats, waterproofing cloth, and fueling torches. By the time the Renaissance began in the 14th century, some surface deposits were being distilled to obtain lubricants and medicinal products, but the real exploitation of crude oil did not begin until the 19th century. The Industrial Revolution had by then brought about a search for new fuels, and the social changes it effected had produced a need for good, cheap oil for lamps; people wished to be able to work and read after dark. Once petroleum forms, it flows upward in Earth’s crust because it has a lower density than the brines that saturate the interstices of the sands and carbonate rocks that constitute the crust of Earth. The crude oil and natural gas rise into the pores of the coarser sediments lying above. For several years people had known that wells drilled for water and salt were occasionally infiltrated by petroleum, so the concept of drilling for crude oil itself soon followed.