GRID · FIELD GUIDE
Oil & Gas Fields — Where the World's Hydrocarbons Come From
Before there is a refinery, a pipeline or a gas-fired power station, there is a field where oil or gas comes out of the ground. So what exactly is an oil or gas field, why are a handful of them so much bigger than all the rest, and why does the raw data make it look like most of the world's oil is in Texas?
Everything downstream on this canvas — every refinery, every pipeline, every gas-fired power plant — begins at a field: an underground accumulation of oil or gas, tapped by wells, where the world's hydrocarbons actually come out of the ground. This layer maps the world's notable oil and gas fields as oil-derrick marks, coloured by what they produce.
A field is not a well. A well is a single hole; a field is the whole deposit, often spread across tens or hundreds of square kilometres and drilled by many wells. So one mark here can stand for something vast — Ghawar in Saudi Arabia, the largest oil field ever found, is a single derrick on the map but stretches some 280 kilometres on the ground.
The colour is what comes up. Oil fields (amber) produce mainly crude; gas fields (cyan) produce mainly natural gas and form their own geography — Norway's Troll and Sleipner, Qatar's North Field, the Russian Arctic; and the largest fields often yield both (lilac), which is why so many North Sea giants carry the blended mark.
One thing to know about the map you're looking at. Wikidata holds over six thousand fields with coordinates, but roughly four-fifths are small US fields imported in bulk, each with a single Wikipedia entry. Left in, they'd bury the world's oil under a cloud of Texan dots and make it look as though the US holds most of the planet's petroleum — which is false; the Gulf holds far more in far fewer fields. So this map shows the notable fields (those covered by at least two Wikipedia languages), which restores the real distribution: the giants that anchor the world view are the genuinely famous ones, spread across the North Sea, the Middle East, Russia, the Caspian and the Americas. It's the same notability filter the dams layer uses to escape a similar skew.
And because reserves are so concentrated — a handful of supergiants hold a huge share of the world's recoverable oil and gas — there's no honest way to size the marks (Wikidata carries no reserve figure, and the gap between Ghawar and a small field is too vast for any invented scale). So every derrick is the same size, the famous fields are simply shown first, and the colour does the work. From here the chain runs on: to refineries, to pipelines and LNG, and to the power plants that burn it.
Frequently asked questions
What is an oil or gas field — is that the same as an oil well?
No, and the difference matters for reading this map. A well is a single hole drilled down to the hydrocarbons; a field is the whole underground accumulation of oil or gas that the wells tap, often spread over tens or even hundreds of square kilometres and drilled by many wells at once. So a field is the geological unit — the deposit — while wells are the straws stuck into it. This map plots fields, not wells, which is why a single mark can represent something enormous: Ghawar in Saudi Arabia, the largest oil field ever found, is a mark here, but on the ground it stretches roughly 280 kilometres and has been drilled by thousands of wells over seventy years. Each derrick mark is one named field; tap it for its name, type and country.
What's the difference between an oil field, a gas field, and one that holds both?
It's about what comes out of the ground. An oil field — the amber marks — produces mainly crude oil (though almost all oil fields release some gas alongside it, called associated gas). A gas field — the cyan marks — produces mainly natural gas, and these form a distinct geography of their own: Norway's North Sea gas (Troll, Sleipner, Ormen Lange), Qatar's vast North Field, the Russian Arctic. And many of the largest fields genuinely yield both in big quantities — the lilac marks — which is why so many of the North Sea giants (Troll, Statfjord, Gullfaks, Oseberg) carry the blended colour. On this map the type comes straight from each field's Wikidata classification: a field listed under both the oil and gas categories, or under the explicit oil-and-gas category, is shown as 'both'.
Why does the map show only 'notable' fields, and not all of them?
Because the raw data would lie to you about where the world's oil is. Wikidata holds well over six thousand fields with coordinates, but roughly four-fifths of them are small United States fields that were imported in bulk, each with just a single Wikipedia entry. Left in, those thousands of tiny Texan and Californian dots would bury the rest of the world — it would look as though most of the planet's oil sits under the US, which is badly wrong: the Gulf states hold far larger reserves in far fewer fields. So we cut the set to fields covered by at least two Wikipedia languages, a simple notability filter, which drops the bulk-import noise and leaves a few hundred genuinely notable fields spread the way the world's oil and gas actually are — the US back around 15%, then Russia, the North Sea, the Middle East and the Caspian. It's the same approach the dams layer uses to escape a similar mapping skew.
Which are the biggest fields, and why do a few dominate so much?
Oil and gas reserves are extraordinarily concentrated: a small number of 'supergiant' fields hold a huge share of the world's recoverable hydrocarbons. The single largest is Ghawar in Saudi Arabia, which has produced more oil than any field in history. Then come names like Burgan in Kuwait, Rumaila in Iraq, the Cantarell complex in Mexico, Daqing in China, Samotlor in Russia, Prudhoe Bay in Alaska, and the great North Sea fields. For gas, Qatar and Iran share the largest field on Earth (the North Field / South Pars). This concentration is a quirk of geology — it takes a rare combination of source rock, reservoir rock and a trap to hold the hydrocarbons, and where all three line up at scale, you get a giant. It's also why this map can't honestly size the marks: Wikidata doesn't carry reserve or production figures, and the gap between Ghawar and a small field is so vast that any made-up size scale would mislead — so every derrick is drawn the same, and the famous giants are simply the ones shown first at world view.
Where do fields fit in the rest of the energy map?
Right at the start. A field is the 'upstream' end of the oil and gas industry — extraction — and everything else on this canvas flows from it. Crude oil from a field travels by pipeline to a refinery, which turns it into petrol, diesel and jet fuel. Natural gas travels by pipeline too, or is chilled to a liquid at an LNG terminal to cross an ocean. And a lot of both ends up at power plants, where it's burned to make electricity. So you can read the energy chain straight off the map: fields (where it comes from) feed refineries and LNG terminals (where it's processed and shipped), pipelines (how it moves), and power plants (one of the main things it's burned for). The carbon-intensity layer then shows the consequence — how much CO2 comes out the far end when that gas and coal are burned for power.
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