The GCC's hydrocarbon reserves are estimated to be worth around $65trn at current export prices, based on new analysis from QNB Capital.
This is almost a third of the $200trn value of world oil and gas reserves, analysts said in a report.
The value of reserves is equivalent to 47 times the GCC's estimated GDP in 2011, or 93 percent of global GDP, it added.
It is also 125 times the estimated $521bn that the region's governments received in oil and gas revenue during 2011.
The rest of the MENA region has the next largest share of global hydrocarbon reserves (23 percent), particularly in Iraq and Iran, followed by Europe and Eurasia (16 percent), mainly Russia and Kazakhstan, QNB Capital added.
In volume terms, the GCC's 495bn barrels of oil account for 36 percent of global oil reserves and its 42trn cubic metres of gas are 22 percent of global gas reserves, the report said.
It added that Saudi Arabia represents almost half the GCC total, followed by the UAE, Kuwait and Qatar which each have around a sixth of the total.
Qatar's share is worth about $9.5trn while Oman has only 1.2 percent of the regional total and Bahrain less than half that amount.
Even after decades of extraction to date, QNB Capital said it estimates that, at current production rates, the current official oil reserves would last for about 70 years and gas for 118 years, on a region-wide basis.