The former Soviet state, with the Caspian Sea region's largest recoverable crude oil reserves, is fairly stable politically and lets foreign firms bid on major energy contracts.
But it is one of several countries (including the United States) that have boosted the royalties private oil companies must pay, thereby increasing the cost of doing business.
And, though not as serious as with its Middle Eastern counterparts, there are some concerns its growing economy will leave less and less energy left over for export.