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Petroleum - Introduction, Properties, Uses, Facts, FAQs

Petroleum - Introduction, Properties, Uses, Facts, FAQs

Edited By Team Careers360 | Updated on Jul 02, 2025 04:44 PM IST

Petroleum is also known as “Black Gold” and the name itself indicates its importance to human’s daily life. Petroleum is utilised to form different products like plastics, gasoline, synthetic fabrics, etc. Due to
this reason petroleum is also referred to as the mother of all commodities.

What is Petroleum?

Petrol meaning (petrol name)

“Petra” is a Greek word and “Oleum” is a Latin word that means “rock oil” is used to derive the word petroleum. When it is drilled from the underground in the liquid form, it is called crude oil.

Crude oil meaning (what is the meaning of crude oil)

Crude oil is a naturally occurring petroleum oil that is composed of hydrocarbon derivatives and other organic materials. Crude oil, basically a type of fossil fuel, is refined to produce usable products including gasoline, diesel, and various other forms of petrochemicals. It is a non-renewable resource, i.e., it can't be replaced naturally at the rate we use it and therefore, a limited resource.

Example of Crude oils:

TYPESPROPERTIESEXAMPLE
Very light oilsvery volatile, evaporating within a few days. As a result, their toxicity levels also evaporate.Gasoline, Jet Fuel, Kerosene, Petroleum Ether, Petroleum Naphtha, and Petroleum Spirit.
Light oilsmoderately volatile and toxic.Grade 1 and Grade 2 Fuel Oils and Diesel Fuel Oils as well as Most Domestic Fuel Oils
Medium oilsMedium oils have low volatility. They have higher viscosity as compared to light oils. It leads to higher toxicity which negatively impacts the environment.Petroleum oil and paraffin oil
Heavy fuel oilsmost viscous and least volatile. Hence, most toxicHeavy fuel oils are grades 3,4,5 and 6. Fuel oils and heavy marine fuels are other examples.

Petrol images are shown below.

Raw Petrol Oil

Petrol image

The Basic Constituents of Petroleum:

Carbon 84-87%, Hydrogen 11-14%, Sulfur 0.06-2%, Nitrogen 0.1-2%, Oxygen 0.1-0.2%, Metals 0-0.14%.

Also read -

This Story also Contains
  1. What is Petroleum?
  2. Different Types of Petroleum Products
  3. How is Petroleum Formed?
  4. Definition of Petroleum Refinery
  5. Purification of Petroleum
  6. Importance of Petroleum
  7. What are Petrochemicals?

The chemical formula for petrol (petrol formula/petrol molecular formula )

Typical petroleum is a mixture of different chemicals such as paraffin, olefins, and naphthalene. Petrol has a basic chemical formula since it is a mixture of various chemicals and is also blended as per its requirement. So, its general petrol chemical formula is CnH2n+2.

Properties of Petroleum (characteristics of petroleum)

  • Petroleum oil appears as very fluid, volatile liquids and also viscous, semisolid materials. The colour of the oil is mainly black or greenish-black tinge in colour but sometimes you can observe that the colour is reddish, light yellow, greenish oil is black in colour, or black with a greenish tinge in colour. Sometimes it can be transparent, light yellow, greenish-yellow in colour.

  • Petroleum oil majorly contains cyclohexanes, alkanes, aromatic hydrocarbons, and other complex hydrocarbons like asphaltenes. The two main constituents of petroleum are carbon and hydrogen.

  • The properties of petroleum oil may vary extensively. Heavier fractions like asphaltene contain more metal concentrations than saturated and aromatic fractions. Apart from this sulphur and nitrogen are present in traces in light petroleum.

Background wave

Different Types of Petroleum Products

Different types of petroleum products are gasoline, liquified natural gas, liquified petroleum gas, kerosene, butane, fuel oil, diesel fuel, propane, paraffin wax, petroleum jelly, microcrystalline wax, etc.

How is Petroleum Formed?

Origin of oil

  • Petroleum is formed from the remains of dead plants (diatoms) such as algae and zooplankton and animals after being decayed by decomposers.

  • When plants and animals died millions of years ago they settled on the seabed. These dead plants and animals decomposed and mixed with sand.

  • Decomposition of the organic matter is done by bacterias which lead to a chemical reaction.

  • After decomposition, the matter having a large amount of carbon and hydrogen is left behind. Due to a deficiency of oxygen at the bottom of the sea, matter does not decompose completely. These partially decomposed organic substances remained on the seabed and eventually were covered with different layers of silt and sand.

  • The whole process took several million years and as a result of high temperature and pressure, the organic matter completely gets decomposed to form oil. The oil formed is known as crude oil.

Where is Crude oil Found?

crude oil—is a fossil fuel and found in large quantities beneath the Earth's surface; under multiple layers of slit of the seabed. It is of foul smell, yellowish black liquid. Crude oil is present in the underground areas known as reservoirs.

petroleum and natural gas deposits diagram

  • Petroleum refining process (describe the process of formation of petroleum).

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An oil refinery or petroleum refining is an industrial manufacturing process, where crude oil is extracted and converted into more valuable goods, such as petroleum naphtha, gasoline, jet fuel, asphalt foundation, heating oil, petroleum kerosene, and liquefied gas. Oil refineries are huge industrial systems containing pipelines that hold fluid streams. The entire process is shown in a simple flowchart below:

An industrial manufacturing process

Related Topics link,

Different constituents of petroleum like gas, diesel, kerosene, etc. have different properties, therefore it is important to separate them. The process of separating different constituents of petroleum is referred to as petroleum refinery.

Definition of Petroleum Refinery

The separation of different constituents of petroleum is done in oil refineries in three steps.

  • In the initial stage, the crude oil is separated into its different components by the distillation process. The heavier constituents settle at the bottom and the lighter constituents rise up as vapour, or float in the liquid.

  • In the second step, the constituents are converted into gas, gasoline, and diesel. This step is known as conversion.

  • The last step known as treating the impurities is treated to obtain different products.

Petroleum Extraction (separation of petroleum)

The most common way of separating oil into different components (called fractions) is to do it using the boiling temperature differences. In petroleum refining, the method of separation used is “fractional distillation”.

Fractional distillation of petroleum diagram

New methods, called conversion, use Chemical processing on certain fractions to produce others. For example, different chemical processing may split lengthier chains into shorter chains. This allows converting diesel fuel into gasoline, depending on the gasoline demand.

Also Read:

Purification of Petroleum

In industry, the refining process is usually called the “downstream” sector, while the “upstream” sector is called the raw crude oil output.

Petroleum refineries in India (crude oil refinery in India)

Gujrat (Jamnagar), Kerala (Kochi), Karnataka, Odisha, Haryana, Maharashtra (Bombay high), Punjab, Tamil Nadu, Assam (Digboi), West Bengal (Haldia).

Few Petrol Industries of India

Petroleum or mineral oil is India’s 2nd biggest source of energy after coal which supplies heat and lighting power, machinery lubricants, and raw materials in different manufacturing industries. Petroleum oil refineries for synthetic textiles, fertilisers, and various chemical industries act as a “nodal industry”. Most of India’s petroleum is found under the anticlines, or domes, where oil is trapped in the unfolding crest along with natural gas.

petroleum shares

Importance of Petroleum

Uses of Petroleum Oil

What are Petrochemicals?

Petrochemicals are the combination of different chemical compounds which are formed from hydrocarbons that are extracted from petroleum.

Also check-

NCERT Chemistry Notes:

Frequently Asked Questions (FAQs)

1. Define petrochemicals.

Petrochemicals are chemical compounds that are derived from natural gas and petroleum.

2. What is gasoline?

Gasoline is a transparent flammable liquid utilized as a fuel. It consists majorly of organic compounds which are obtained by the fractional distillation of petroleum oil.

3. Where does petroleum come from ?

Petroleum is found under the seabed which is formed when large quantities of dead organisms are buried under sedimentary rock and subjected to temperature and pressure for million years.

4. Where is crude oil found in India?

Gujrat (Jamnagar), Kerala (Kochi), Karnataka, Odisha, Haryana, Maharashtra (Bombay high), Punjab, Tamil Nadu, Assam (Digboi), West Bengal (Haldia).

5. Who discovered petrol?

In 1847, the Scottish chemist James Young discovered petroleum.

6. What is the chemical formula of petrol?

The general petrol chemical formula is CnH2n+2.

7. Write down the meaning of oil refinery.

Crude oil processing for use for different purposes.

8. What is the significance of the hydrogen-to-carbon ratio in petroleum?
The hydrogen-to-carbon (H/C) ratio is an important characteristic of petroleum:
9. What is the significance of fractional distillation in petroleum refining?
Fractional distillation is a crucial process in petroleum refining:
10. How do different types of crude oil impact refinery operations?
Different types of crude oil can significantly affect refinery operations:
11. What is the role of isomerization in petroleum refining?
Isomerization is an important process in petroleum refining:
12. How does the molecular structure of asphaltenes affect petroleum processing?
Asphaltenes, large complex molecules in crude oil, significantly impact petroleum processing:
13. What is the difference between light and heavy crude oil?
The terms "light" and "heavy" refer to the oil's density and flow characteristics:
14. What are the main differences between sweet and sour crude oil?
Sweet and sour crude oils differ primarily in their sulfur content:
15. What are the main differences between conventional and unconventional oil resources?
Conventional and unconventional oil resources differ in several ways:
16. How does the API gravity scale relate to petroleum quality?
The API (American Petroleum Institute) gravity scale is a measure of how heavy or light a petroleum liquid is compared to water:
17. How does thermal cracking differ from catalytic cracking in oil refining?
Thermal and catalytic cracking are both used to break down larger hydrocarbons, but they differ in several ways:
18. What is petroleum and how is it formed?
Petroleum, also known as crude oil, is a naturally occurring fossil fuel formed over millions of years from the remains of ancient marine organisms. When these organisms died, they sank to the bottom of oceans and were buried under layers of sediment. Over time, heat and pressure transformed this organic matter into a complex mixture of hydrocarbons that we call petroleum.
19. Why is petroleum called a "fossil fuel"?
Petroleum is called a fossil fuel because it is derived from the fossilized remains of prehistoric plants and animals. The term "fossil" refers to the preserved remains or traces of ancient life forms, while "fuel" indicates its use as an energy source. This name emphasizes both its origin and its primary application in modern society.
20. How does petroleum formation relate to plate tectonics?
Petroleum formation is closely linked to plate tectonics:
21. What is the role of biomarkers in petroleum geochemistry?
Biomarkers, also known as molecular fossils, play a crucial role in petroleum geochemistry:
22. What are the main challenges in offshore oil extraction?
Offshore oil extraction faces several unique challenges:
23. How does petroleum impact the global economy?
Petroleum plays a crucial role in the global economy:
24. What are the environmental concerns associated with petroleum use?
The use of petroleum raises several environmental concerns:
25. What is the octane rating of gasoline and why is it important?
The octane rating of gasoline measures its ability to resist "knocking" or premature ignition in an engine. Higher octane ratings indicate greater resistance to knocking. This is important because:
26. What is peak oil theory?
Peak oil theory suggests that global oil production will reach a maximum rate, after which it will gradually decline. This concept, introduced by geologist M. King Hubbert, is based on the finite nature of oil reserves and the observation that individual oil fields' production tends to follow a bell-shaped curve. While controversial, this theory highlights the need for sustainable energy alternatives.
27. What is fracking and why is it controversial?
Fracking, or hydraulic fracturing, is a technique used to extract oil and gas from deep underground rock formations. It involves injecting a high-pressure mixture of water, sand, and chemicals into a wellbore to create cracks in the rock, allowing oil and gas to flow more freely. It's controversial due to environmental concerns, including potential groundwater contamination, increased seismic activity, and methane emissions.
28. How is crude oil refined into usable products?
Crude oil refining involves several steps:
29. What is the role of catalysts in petroleum refining?
Catalysts play a crucial role in petroleum refining:
30. How does the sulfur content of crude oil affect its processing and use?
The sulfur content of crude oil is an important factor:
31. How does the composition of petroleum vary?
The composition of petroleum can vary significantly depending on its source and location. Factors such as the age of the deposit, depth, temperature, and pressure during formation affect its composition. This variation is why crude oil from different regions can have different properties and require different refining processes.
32. How is petroleum extracted from the Earth?
Petroleum is extracted through a process called drilling. This involves:
33. What are the main uses of petroleum products?
Petroleum products have numerous applications, including:
34. How does the chemical structure of hydrocarbons in petroleum affect their properties?
The chemical structure of hydrocarbons in petroleum greatly influences their properties:
35. How do petrochemicals differ from other petroleum products?
Petrochemicals are chemical products derived from petroleum, distinct from fuels and lubricants:
36. What is the significance of the carbon number in petroleum chemistry?
The carbon number is crucial in petroleum chemistry:
37. How do enhanced oil recovery (EOR) techniques work?
Enhanced oil recovery techniques are used to increase the amount of crude oil extracted from a reservoir:
38. What are the main components of petroleum?
Petroleum is primarily composed of hydrocarbons, which are molecules containing only hydrogen and carbon atoms. The main components include:
39. How does petroleum exploration use seismic technology?
Seismic technology is a key tool in petroleum exploration:
40. How do petroleum reservoirs trap and store oil?
Petroleum reservoirs trap and store oil through specific geological structures:
41. How does the viscosity of crude oil affect its extraction and transportation?
The viscosity of crude oil has significant impacts on its extraction and transportation:
42. What are the environmental impacts of oil sands extraction?
Oil sands extraction has several environmental impacts:

Also Read

Benzene Reactions - Sulfonation, Nitration and Halogenation

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Hydroboration and Oxidation

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Articles

Questions related to

Have a question related to ?
which is better for future petroleum engineering or computer science engineering

Hello Nanditha krishana,

Both the fields are valuable, but Computer Science Engineering (CSE) offers better career opportunities and career advancement in today's digital era. Since AI, data science, cybersecurity, and software development are fast-growing, Computer science skills are in highest demand globally across industries. Conversely, Petroleum Engineering is more specialized and connected to the oil and gas industry, which can be lucrative but is also subject to volatile global energy needs and environmental trends toward cleaner energy.
Therefore, if you seek flexibility, creativity, and a booming industry, CSE is the better option for the future. Nevertheless, the optimal path always relies on your own interest and career aspirations.

Read Complete Answer
gopi 24 April,2025
I want to complete degree in Petroleum

How to Complete a Petroleum Engineering Degree?

1. Degree Options:

B.Tech/B.E. (4 years) | Diploma (3 years) | M.Tech (2 years)

2. Eligibility :

B.Tech: 10+2 with PCM

Diploma: 10th with Science & Math

M.Tech: B.Tech in Petroleum or related field

3. Entrance Exams :

JEE Advanced/Main (For IITs, NITs)

State CETs & Private University Exams

4. Top Colleges :

IIT (ISM) Dhanbad, RGIPT Amethi, PDEU Gujarat, UPES Dehradun

5. Career Opportunities :

Oil & Gas Companies – ONGC, IOCL, BPCL, Shell, Reliance

Read Complete Answer
harsh singh 06 April,2025
What is the placement status of b tech in petroleum

Hello,

Regarding your query, the placement status of B.Tech in Petroleum Engineering is generally good, where many students secure jobs in oil  and gas sector, with an average salary packages ranging from 6 to 10 LPA.

Read Complete Answer
Sadaf Ghanchi 04 April,2025
how to apply for petroleum engineering abroad?

Hi Renimol,

Applying for petroleum engineering abroad involves several steps, from selecting the right university to completing the application and securing your admission. Here's a detailed guide:

1. Research Programs and Universities
Look for universities known for their petroleum engineering programs. Countries like the United States, Canada, the United Kingdom, Norway, Australia, and UAE are popular destinations.
Use platforms like QS World University Rankings or US News Rankings to identify universities with strong engineering faculties.
2. Understand Admission Requirements
Each university has specific requirements, but commonly you’ll need:

Academic Qualifications: A strong background in mathematics, physics, and chemistry is essential. For master’s programs, a bachelor’s degree in engineering or a related field is required.
Standardized Tests:
For undergraduate: SAT or ACT scores.
For postgraduate: GRE (if required by the institution).
Language Proficiency:
English-taught programs require scores in TOEFL or IELTS.
Other certificates accepted may include PTE or Duolingo English Test in other universities.
3. Application Documents Preparation
Academic transcript and degree certificates.
Statement of Purpose which clearly indicates your interest in pursuing petroleum engineering.
Letters of recommendation from teachers or professionals with knowledge about your area of interest.
A CV/Resume detailing your relevant work experience, internship, or projects.
Financial documents when applying for scholarships or student loans.
4. Applying Through the Right Channels
Undergraduate Programs: Use application portals like Common App (USA) or UCAS (UK). Other countries, such as Canada and Australia, have separate applications for each university.
Postgraduate Programs: Apply directly through the university's website or centralized portals like Studielink (Netherlands) or DAAD (Germany).
5. Scholarships and Funding
Scholarships to look for:
Fulbright Scholarships (USA).
Commonwealth Scholarships (UK).
DAAD Scholarships (Germany).
University-specific grants or bursaries.
Some countries also offer government scholarships for international students.
6. Student Visa
Once admitted, apply for the student visa of the target country.
Prepare for Visa Interviews (if required), proof of financial support, Admission letters, and health insurance.
7. Preparation for Life Abroad
Secure accommodation and flights.
Understand the expectations of the culture and academic practices of your destination.
Best Petroleum Engineering Universities
Stanford University (USA)
Imperial College London (UK)
University of Alberta (Canada)
University of Texas at Austin (USA)
Norwegian University of Science and Technology (NTNU) (Norway)

Read Complete Answer
Mehndi Roy 12 December,2024
I scored 58 percentile in Jee mains 2024..can I get admission on Dibrugarh University in Petroleum Engeenering

Dear

According to the information Dibrugarh University's B.Tech  in Petroleum Engineering requires a minimum of 45% in 10+2 exams with Physics, Chemistry, and Mathematics and a valid JEE Mains score. Since your JEE Mains percentile is 58 , you meet the minimum criteria for eligibility.

For more information you can read the official notification here .

Thanks.

Read Complete Answer
Lalit Kumar 07 November,2024
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