1,687,300,000,000 is the massive number that is the total number of barrels of oil that are in the ground. This number is known as the proven reserves of oil.

The 12 nations that make up OPEC have the lion’s shares of this.

Algeria                  12,200,000,000
Angola                  12,700,000,000
Ecuador                 8,400,000,000
Iran                        157,000,000,000
Iraq                        150,000,000,000
Kuwait                  101,500,000,000
Libya                      48,500,000,000
Nigeria                  37,100,000,000
Qatar                     25,200,000,000
Saudi Arabia       265,900,000,000
UAE                       97,800,000,000
Venezuela          297,600,000,000

Total:                   1,213,900,000,000

So OPEC’s 1,213,900,000,000 out of the total of 1,687,300,000,000:
1,213,900,000,000 / 1,687,300,000,000 = 71%.

Thus OPEC “own” 71% of the world’s oil reserves. That is the real big oil.