OPEC & Oil and Gas Cooperation:
Oil cooperation has already been established internationally. The foremost authority on oil is OPEC, or the Organisation for the Petroleum Exporting Countries, which includes Saudi-Arabia, Nigeria, etc. OPEC is a legal cartel which collaborates amongst its members to attempt to fix prices and the supply of oil. Generally, countries will only cooperate with each other to form cartels, in order to gain the maximum profit by achieving the highest price. Monopolies, such as Russia's Gazprom, supply a significant proportion of energy to a particular region (in this case, Central and Eastern Europe), making substituting away from the monopoly's energy not a particularly viable option.
OPEC has occassionally responded to world pleas, especially from the US Government, on increasing supply to lower the world price of oil in the aftermath of economic shocks, such as when OPEC increased the oil supply by a small amount in response to the economic destruction of Hurricane Katrina.
Cooperation to Help Ease The World Price:
The only feasible way to ease the burgeoning world price of oil is to increase competition in the market. Because firms are either in cartels or are monopolies, all competition is stifled. Cartels would have to be dismantled, with the OPEC member states unlikely to do so, and have the 'invisble hand' determine the most efficient price level and supply.
I know this seems counter-intuitive, but what you actually want is less energy cooperation and more competition.