 It has reserves containing 137.5 billion bbl of crude oil, the second largest in the world, producing around four million bbl/day.Additionally, Iran has an estimated 988.4 trillion cubic feet of natural gas, around 16 percent of total world reserves, which makes it to play a key role in the global energy security equation.Russia's economy ranks as the twelfth largest by nominal GDP and sixth largest by purchasing power parity in 2015.