"Strategic National Asset"
Short term, this could end up being a boost for Russia's entire economy. The question is, now that the oil industry in Russia is controlled by the Kremlin, will the Kremlin hold back exports to boost Russia's internal economy, and push up oil prices across the world to increase profits for the oil companies?
How much will the artificially created increased demand within Russia reduce the available oil for export to the rest of the world?
It will rather stabilize the domestic consumption and export levels. There is no reason for consumption going up when prices stay frozen.