Oil & Gas Engineering: Overview

Oil rig in the ocean at sunset

Oil & gas engineering

Around 82% of the worlds energy comes from fossil fuels such as oil and gas.  Although inroads into renewable energy sources is ongoing, at the current rate, it could be another 200 years before we can give up fossil fuels completely [1].  Therefore, until we can switch to other forms of power generation there will always be a need for quality oil & gas engineers!

In order to produce electricity, or make the plethora of consumer products we get from oil and gas, you need to find it, extract it safely, process it, and transport it to a power generating facility or processing plant.  All part of this process are dangerous, and care needs to be taken not to ignite the fuel before intended.  Oil is a liquid, so fairly "easy" to detect and contain, but natural gas requires pressure vessels and has no smell - so it can be hard to contain and difficult to detect leaks in the extraction process.  Methanethiol is added to natural gas before it reaches houses and gives gas it's well known "rotten egg" smell to help home owners detect a gas leak [2].

The three streams

In the oil and gas industry there are three streams, upstream, midstream, and downstream.  Each stream has it's own engineering problems to solve and safety issues to contend with, so knowing which stream interests you will help determine the kind of oil & gas engineer you want to be.


An illustration of surveying underwater looking for gas and oil

Upstream is used to describe the exploration and production of crude oil and natural gas.  This includes activities such as geological surveys, drilling, and extraction [3].  Natural gas is often found above oil deposits as it's lighter than oil [4] and forms as part of the same natural processes that produce oil deposits.


Midstream is where crude oil and natural gas is transported or stored ready for processing into a usable form [3].  Oil and gas deposits can be found under the sea or land, and often in remote areas, so transportation usually involves the building of an infrastructure in the form of long pipelines and storage tanks as well as large tankers to ferry the crude oil from off shore oil rigs.  Maintenance of which is key to ensure a reliable supply and prevent an environmental disaster.


Downstream is the main "processing" stream where crude oil and natural gas are processed into usable products from fuel to heat homes and power cars and aeroplanes or to power turbines to generate electricity through to plastics, fertilisers and dyes [3].  This side of the process is more in the realms of chemical engineering in terms of the extraction and separation of chemicals from crude oil and gases in order to make materials such as plastics, polymers, and fertilisers.


Crude oil and natural gases need to be refined and processed to make the products we use. There are many processes used to refine oil and gas from separation, condensation, and distillation to name but a few [5].  Refining is where oil & gas engineering meets chemical engineering and it's amazing how many different products we use in everyday life are created from the raw 


Working with oil & gas is a risky business, and there have been a number of high profile accidents which have caused loss of life, and severe pollution as well as billions in clean up costs [6].  The industry makes copious use of standards and procedures in order to maintain the infrastructure and equipment in order to keep workers safe, and prevent pollution.

Inspection and testing of the infrastructure to ensure its structural integrity is key.  This is especially true in offshore platforms where structures and machines not only need to be capable of bringing oil and gas to the surface, they must also do this is the harsh environment of the sea.  It's not just the water, but the weather and also potential collisions from other water craft that need to be considered.

Into the future

The pressures on oil and gas companies - from moving toward a "clean" energy economy to the Paris Agreement - means they are having to plan for the future [7].  They are looking to see how they can make a positive contribution to climate change, and look at ways to reduce their carbon footprints.  This will involve investment in clean technologies, efficiency improvements, and updating of infrastructure.

In addition, geopolitical risks have increased over the last few years.  Consumer energy prices have increased as countries refuse to sell their resources due into conflicts such as the Ukraine war.  Government policies in the UK and across Europe have changed to try and reduce their reliance on foreign oil and gas supplies [8] [9].

Regardless of the economic, environmental, and geopolitical nature of the oil and gas industry - talented engineers will always be needed to ensure the supply meets demand.  Creating more efficient machines, introducing digital strategies, reducing the carbon footprint, and creating innovative processing plants - all are ways you can contribute to this vital industry.


[1] R. Rapier. "Global energy trends: insights from the 2023 statistical review of world energy." Forbes. Accessed: Aug. 29, 2023. [Online] Available: https://www.forbes.com/sites/rrapier/2023/08/06/global-energy-trends-insights-from-the-2023-statistical-review-of-world-energy/?sh=18bbe5435021
[2] Energy Education. "Mercaptan". University of Calgary. Accessed: Aug. 29, 2023. [Online]. Available: https://energyeducation.ca/encyclopedia/Mercaptan#:~:text=Mercaptan%2C%20also%20known%20as%20methanethiol,
[3] EnergyHQ. "UPSTREAM? MIDSTREAM? DOWNSTREAM? WHAT’S THE DIFFERENCE?". EnergyHQ.com. Accessed Aug. 29, 2023. [Online]. Available: https://energyhq.com/2017/04/upstream-midstream-downstream-whats-the-difference/
[4] Energy.gov. "Fossile energy study guide: natural gas". Energy.gov. Accessed: Aug. 30, 2023. [Online]. Available: https://www.energy.gov/sites/prod/files/2014/02/f8/HS_NatGas_Studyguide_draft2.pdf
[5] P. Baheti. "How is plastic made? A simple step-by-step explanation." British Plastics Federation. Accessed: Aug. 30, 2023. [Online]. Available: https://www.bpf.co.uk/plastipedia/how-is-plastic-made.aspx
[6] J.P. Rafferty. "9 of the biggest oil spills in history." BritannicaAccessed: Aug. 30, 2023. [Online].  Available: https://www.britannica.com/list/
[7] International Energy Agency. "The Oil and Gas Industry in Energy Transitions." International Energy Agency. Accessed: Sep. 7, 2023. [Online]. Available: https://www.iea.org/reports/the-oil-and-gas-industry-in-energy-transitions
[8] Department for Business, Energy & Industrial Strategy. "UK to phase out Russian oil imports". GOV.UK. Accessed: Sep. 7, 2032. [Online]. Available: https://www.gov.uk/government/news/uk-to-phase-out-russian-oil-imports
[9] European Commission. "In focus: Reducing the EU’s dependence on imported fossil fuels." Europa. Accessed: Sep. 7, 2023. [Online]. Available: https://commission.europa.eu/news/focus-reducing-eus-dependence-imported-fossil-fuels-2022-04-20_en


Picture credits

Pump-jack mining crude oil with the sunset by Zbynek Burival is used under Unsplash licence.

Rex virtual drilling by Chooywa is used under CC BY-SA 4.0 licence

Oil Tanker Stride in Colon Panama 2016 by Paul Harrison is used under CC BY-SA 4.0 licence.

Small plastic tubes by Sigmund is used under Unsplash licence / image cropped.

Professional Institutions

Professional Institutions are specialist organisations which offer guidance, support and training for their members. The main ones for Oil & Gas engineers are listed below.


Liane Frydland

Liane Frydland
Academic Liaison Librarian for
Chemical Engineering,
Civil & Environmental,
Mechanical &Aerospace Engineering

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