Buffett's purchase of PetroChina was an early recognition of the these firms' investment potential. Since then, Buffett has exited his position; but a fall in energy prices and political risk has given these companies an attractive valuation. PetroChina's extensive refinery operations, along with state-set pricing, has lowered their margins, but the Russian companies are doing better business than ever. Gazprom and Lukoil are trading at about a third off recent highs.
Of course, there are a few concerns. First, commodity prices are lower. But these firms are a bargain even with lower oil and natural gas prices. Second, there is political risk in investing in Russia. Though this risk is considerable for a company such as Mechel (full disclosure: I am long MTL), it's hard to imagine companies as well connected as Gazprom or Lukoil taking another hit. The war with Georgia, to the extent it matters at all, increases Russian energy grip over Europe. Last, state-owned firms may be unlikely to invest in new production. But current valuations compensates for low growth, and the Russians seem to know what they're doing.