Oil is a natural substance consisting of a mixture of hydrocarbons. The color of the oil is usually black or dark brown, and it may have a greenish-orange color depending on the composition. In general, oil is a highly flammable oily and viscous substance. The relative density of the oil mixture is always less than one, meaning that its weight is less than the weight of water, which allows it to float on it without dissolving in it because it is an oily compound. This explains the buoyancy of oil slicks in the seas and oceans when an oil spill occurs from ships.
The odor that characterizes the oil is mostly due to the aromatic compounds that are part of the hydrocarbon mixture with alkanes and cycloalkanes and other materials such as paraffin, naphthalene, sulfur compounds, nitrogen compounds, terpenes and phenols.
Oil is found in most cases in underground sediments and some places where oil is found remains undiscovered.
How is oil formed
Oil is an accumulation of organic matter that has not completely dissolved, that is, from large masses of single-celled marine organisms, such as phytoplankton and zooplankton, buried at the bottom of oceans and seas millions of years ago. This theory was first postulated by the Russian scientist Lomonosov during the eighteenth century and confirmed by the Russian scientist Mendeleev in 1877.
Oil formation begins through the accumulation of organic matter in such large quantities that microorganisms are unable to decompose it. This can happen in shallow coastal areas rich in organisms and nutrients, but with little oxygen at the sea floor. Over millions of years, dead organisms accumulate on top of each other in layers, which leads to an increase in pressure and temperature, which leads to chemical and physical reactions that change the state of matter.
To be clear, the large organisms that have died do not contribute to the formation of oil fields, some complex organisms such as fish and algae can be part of this biotransformation process, but large organisms rarely participate in it.
Initially kerogen is made from organic matter buried by anaerobic bacteria, then slowly turns into liquid and gaseous compounds made up of carbon and hydrogen (hydrocarbons). This process occurs rapidly at a depth of 2-3 km underground, but when we say a rapid transformation, we mean a period of at least 5-10 million years in the best of circumstances, and in the absence of these conditions, the process may take 100 million years.
The time required to form oil as well as coal and methane gas makes this type of resource non-renewable to humans, especially given the speed at which it is consumed.
When was the oil discovered?
The common belief is that oil was discovered in recent history, but the fact is that oil has been known since ancient times as “shale oil”. The word “petroleum” became used in the middle of the sixteenth century, and it is derived from two Latin words, the word petra, which means rock, and the word oleum, which means oil.
In the beginning, oil was extracted from the areas where it appears without drilling. This oil was used to ignite lamps or as a substance to prevent water from seeping from the surfaces, and it was mentioned in the Iliad (poetic epic telling the story of the Trojan War) as a “permanent fire” used to set fire to the Hostile ships.
In addition, the oil has been used for medicinal purposes, as some of the places where it appears have become known as spas.
In the mid-nineteenth century, Western society was asking for cheap lighting. Edwin Drake was the first to conduct an underground oil exploration in August of 1859 near Titusville, Pennsylvania. Workers are said to be shocked by the idea of his strange project “digging the ground for oil” and thinking it was a foolishness. But it succeeded and an oil well was drilled in the world in Pennsylvania, USA.
Before the advent of oil, humans used to hunt whales to obtain the fat from them for the purpose of using it to light lamps, but after the discovery of oil, it became possible to dispense with whale fat, which contributed to reducing its hunting. In 1861, an article was published in the American magazine Vanity Fair with a picture showing sperm whales celebrating the discovery of oil wells in Pennsylvania, because the oil extracted from these wells contributed to the reduction of whaling.
A New York City attorney named George Bissell spoke about the active potential of the oil that was extracted in Pennsylvania for the formulation of drugs to treat headaches, dental pain, stomach ailments, rheumatism and skin diseases. Bissell was also convinced that “rock oil” could be used as a lighting oil instead of whale fat or charcoal. .
Certainly, no one expected the tremendous success and the great impact that oil might have on the development of society all over the world. The basic idea of oil exploration was to use it to illuminate city streets and possibly as a lubricant. But no one imagined that the exploitation of this substance would change the wealth, economy, society and the environment on the planet.