Petroleum, Rock Oil, Crude Oil, Seneca Oil, Texas Gold, Black Gold or any other name you may know it by is the world’s most important energy source; consider that it accounted for the highest contribution (33%)to the global energy mix in 2015 compared to coal (30%) , Natural Gas (24%), Nuclear (4%), wind and renewables (2%). The average global consumption of Crude Oil was 95.53 million barrels per day in Q4 2015.
What is Crude Oil?
Crude Oil is a naturally occurring liquid or semi-solid mixture of hydrocarbons (hydrogen and carbons) found beneath the earth surface. It is the source of common petroleum products and fuels line Petrol, Diesel and Aviation fuel.
Formation of Crude Oil
Oil is formed from the breakdown of large molecule Fat, Oil and waxes which are first transformed to Kerogen. The Fat, Oil and Wax are derived from the decomposition of dead Plants and Marine Organisms which settled at the bottom of the Sea in layers of Clay, Silt and Sand. The drying up of the Sea, impacts of extreme temperature, pressure, time and geological shifting result in the subsequent formation of fluid and dynamic oil pool in a porous reservoir rock. An oil formation occurs when the reservoir rock becomes trapped and encased in a non-porous rock formation such as a salt dome called the Cap rock. The deployment of oil well drilling technologies ensure that oil in the reservoir rock can be liberated and brought to the surface for production.
2015 data from OPEC indicates that there is about 1.5 trillion barrels of global proven reserves of crude oil which can (will) last another 53 years at current rate of production if additional reserves are not added. Venezuela, Saudi Arabia and Canada in that order are the largest holders of crude reserves among the committee of nations.
Properties of Crude Oil
Hydrocarbons being the main contents of Crude Oil can be broadly classified into Alicyclic (paraffinic), Aliphatic (Naphthenic) and Polycyclic Aromatic hydrocarbons (you may want to brush up on New School Chemistry by Ababio). In addition to hydrocarbons, crude oil also often contains some compounds of Oxygen and Nitrogen, Sulphur, Metals (Nickel, Vanadium, and Iron) and inorganic salts.
Commercially, the most important parameters are the Sulphur content and the API gravity. The API gravity is a measure of density of the crude compared to the density of water at 60oF. It is an indicator of the likely yield of the commercially desirable light fractions (Naphtha, Petrol, Kerosene and Diesel) expected from a crude oil grade during distillation. API gravity of crude is measured between ranges of 45o – 7o API. Preference is for API gravity between 31 – 45 o (Light), API gravity between 23 – 31 o are called Medium while those with API gravity lower than 20 o are referred to as Heavy crudes.
Sulphur and Sulphur compounds are not desirable in crude oil because they are foul smelling and poisonous; with a tendency to damage refinery equipment due to their corrosive nature. Crude Oil grades are generally classified as Sweet or Sour depending on the sulphur content; 0 – 0.5%wt sulphur content for sweet while Sour crude have greater than 0.5%wt sulphur content.
Other parameters of interest in Crude Oil are the nitrogen content and BS&W (base sediment and water content). The properties of crude oil determines how much traders and refiners are willing to pay for a barrel full of oil. Today, that’s just a little above $50.
We hope you enjoyed this insight into crude oil.