All about petroleum

You probably studied oil in school, but do you remember all the details? On the Modal blog, we’ll show you everything about this essential natural resource.

In This Post, You Will See:

  • What is Oil
  • Origin of Oil
  • Composition
  • Extraction
  • Oil Derivatives
  • Oil in Brazil
  • Environmental Problems

What is Oil
Oil is a natural fuel derived from the decomposition of organic matter over thousands of years, classifying it as a fossil fuel. Found in deep ocean sediments, seas, lakes, and on land, it is a non-renewable energy source mainly used for producing gasoline and diesel.

Origin of Oil
The origin of oil is debated, but the most accepted theory is that it results from the deposition of organic matter (animals and plants) buried at the seashore millions of years ago. Under water pressure, phytoplankton gradually transforms into oil through a process requiring specific temperature and pressure conditions, resulting in a mixture of carbon and hydrogen molecules.

Oil is primarily composed of hydrocarbons, such as butane (C4H10) and methane (CH4). Its chemical composition also includes small amounts of nitrogen, oxygen, salts, and metallic residues. Typical proportions are:

82% carbon;
12% hydrogen;
4% nitrogen;
1% oxygen;
1% salts and metallic residues.

The extraction process of oil involves three basic stages:

Exploration: Locating mineral deposits in a sedimentary basin based on subsurface analyses.
Drilling: Once a deposit is discovered, drilling occurs to assess the economic feasibility of mining.
Extraction: Using special equipment for extraction. Offshore platforms and ships use pumps for seabed extraction. On land, specific equipment is used to pump or blast the found oil.

Oil Derivatives
Oil derivatives are obtained through refining, involving chemical processes like cracking, reforming, alkylation, and hydrotreating. According to ANP, the main derivatives are:

Petroleum gas: Used for heating and in industry.
Liquefied petroleum gas: Used for cooking.
Naphtha: Raw material for the petrochemical industry and also converted into gasoline.
Gasoline: Used as fuel.
Kerosene: Used as jet turbine fuel.
Diesel oil: Mainly used in road, water transport, and thermoelectric plants.
Fuel oil: Heat source in industry.
Residues: Used as material to manufacture other products (coke, asphalt, waxes).

Oil in Brazil
Almost 15 years after the discovery of oil on Brazilian soil, Petrobras was created in 1953 during the government of President Getúlio Vargas. In 2006, the pre-salt layer, a vast area with large oil reserves off the Brazilian coast, was discovered. Exploration began in 2008, and currently, pre-salt accounts for 60% of Brazil’s oil production.

Environmental Problems
Oil, being a non-renewable and polluting fuel, presents several environmental problems. Its extraction, consumption, and improper disposal of its derivatives have a significant environmental impact. Oil spills during extraction, especially in aquatic environments, cause biodiversity loss and water quality degradation, negatively affecting populations dependent on fishing and other activities.