Becoming Big Oil: How the 10 Largest Oil Companies Were Born

Becoming Big Oil: How the 10 Largest Oil Companies Were Born

The size and scope of Big Oil is truly mind-boggling.

For example, Chinese government-owned Sinopec, the world’s largest oil company by 2014 revenues, employs 358,571 people and brought in a whopping $455 billion in revenue last year.

Royal Dutch Shell is no slouch, either. The world’s third largest oil company generated $422 billion in revenue in 2014 and is the U.S. market leader in gas stations with 25,000.

Collectively, the numbers from the world’s 10 biggest oil companies are even more impressive. Worldwide, they generated $3.26 trillion in revenue in 2014, which is more than the entire GDP of the United Kingdom. The combined daily oil production of these same companies is 40 million barrels of oil, enough to fill 2,543 Olympic-sized swimming pools.

Big Oil has more behemoth companies than all other industries combined. Even with the recent decline in oil prices, half of Fortune’s 10 Largest Companies list is composed of oil conglomerates. The Swiss commodity giant Glencore, one of the “other” five companies on the list, also makes a significant portion of revenue from trading oil.

The question is: how did these companies get so big?

Today’s infographic, from drill rig supplier Rigsource, tries to answer this question. Looking at a century of mergers and acquisitions, it becomes clear that these companies were not always giants. They became their current size through various mergers and acquisitions that happened over the course of the last century, and it is these economies of scale that has allowed them to generate the kind of revenue they do today.