What Is Oil?

We explain what oil is, its origin and how this hydrocarbon is formed. In addition, its properties and various uses.

1. What is Oil?

Oil is called a bituminous substance, dark in color and viscous texture , composed of a mixture of organic hydrocarbons insoluble in water , also known as  black  or  raw gold . Its physical properties (color, density) may, however, be diverse, depending on the concentration of hydrocarbons present, which includes the following:

• Paraffins (saturated hydrocarbons).
• Oleifins (ethylene hydrocarbons).
• Acetylenic hydrocarbons.
• Cyclic or cyclic hydrocarbons.
• Benzene or aromatic hydrocarbons.
• Oxygenated compounds (by oxidation and polymerization).
• Sulfur compounds.
• Cyclic nitrogen compounds.
• Dissolved content of nitrogen, sulfur, oxygen, cholesterol, porphyrins and traces of nickel, vanadium, nickel, cobalt and molybdenum.

Given its complex chemical composition, oil is a non-renewable natural resource of enormous economic value, as a raw material for various organic materials (obtained in the petrochemical industry) and various solvents, additives and, above all, fossil fuels.

Therefore, it is massively extracted from its place of formation: the subsoil. By means of extraction facilities known as wells, their deposits (usually close to those of natural gas) are located in the lower layers of the subsoil, and the liquid is extracted using various techniques, according to the nature of the soil and the geographical arrangement, which it can be on firm land or on the seabed or rivers, lakes, etc.

The commercialization of oil  is the main economic activity of many countries such as Venezuela , Saudi Arabia, Russia, Iraq or Iran, most of which organize their oil production around the guidelines of the Organization of Petroleum Exporting Countries (OPEC) Founded in 1960 and currently based in Vienna, Austria.

2. Petroleum origin

Petroleum is considered a hydrocarbon of fossil origin , that is, due to the accumulation of large amounts of organic matter millions of years ago, such as zooplankton and algae from dried out lake regions over the centuries, whose anoxic bottoms (without oxygen) were buried under layers of sediment.

Under these conditions, the pressure and heat would have caused chemical and physical transformation processes (natural cracking) that would produce as a product various substances: bitumen, natural gases and other hydrocarbons such as oil.

There is also another theory about its origin, which is attributed to abiogenetic sources  (not from organic matter). This theory is not completely ruled out, but it has the support of the minority of the students of the subject, since it cannot explain many of the contents present in the oil without previous presence of living beings .

3. How is oil formed?

The exact chemical processes that result in oil are still unknown, but it is known that its formation is linked to geological traps (oil traps), which are subsoil structures conducive to the accumulation of oil, keeping it trapped and unable to escape to the pores of an underground permeable rock (storage rock), or other similar structures. Thus arise the oil fields.

4. Oil properties

Oil is, as stated, one liquid , viscous, dense color tending to black or yellow (according to its concentration of hydrocarbons), with an unpleasant odor (product of sulphates and nitrogen) and enormous power caloric ( 11000 Kcalories per Kilogram). These properties will vary according to the type of oil we are talking about: paraffin based (fluids), asphalt base (viscous) and mixed base (both).

5. Uses of oil

Petroleum is a powerful source of industrial materials, from which solvents , fuels, fuels, alcohols and plastics are obtained . To do this, the crude oil must be subjected to various refining and distillation processes  (fractional distillation), in order to separate and extract its ingredients.

Progressively heated from 20 ° C to 400 ° C, the oil separates in the following phases:

• Natural gas  (20  ° C) . Combustible hydrocarbon gases such as ethane, propane, and butane (liquefied petroleum gases), which are used to feed stoves, lighters, etc.
• Naphtha or  ligroin  (150 ° C) . A substance called benzine or petroleum ether, a mixture of highly flammable and volatile compounds that is used as a non-polar solvent, or as a base for other organic compounds.
• Gasoline (200 ° C) . The quintessential fuel for internal combustion engines, such as those of motor vehicles or certain power generation plants , varies in range according to their octane rating (purity) and is one of the most coveted petroleum products.
• Kerosene (300 ° C) . Also called kerosene, it is a fuel of low purity and low yield, but much cheaper than gasoline, used as a solvent, as a base for pesticides, and for lamps or rural kitchens.
• Diesel (370 ° C) . Known as diesel, it is a fuel composed of paraffins, ideal for heaters and outboard engines (diesel engines), which are cheaper but have much lower performance.
• Fueloil (400 ° C) . It is the fuel derived from the heaviest oil that can be derived at atmospheric pressure, used to feed boilers, furnaces and as a material to be distilled again, to obtain asphalts, lubricating oils and other substances.