Why Russia needs the "South Stream"?

The Construction of the "South Stream" pipeline from Russia to South-Eastern and Central Europe has encountered the resistance of the European Commission, and Arseniy Yatsenyuk, the Prime Minister of the Ukraine has appealed to block the project which, in his opinion, is intended to deprive the Ukraine of Russian gas transit. Is it real?

The concept of an energy superpower more than satisfies the Russian leadership. But there are often obstacles, where Russia's ambitions collide with other countries. At a meeting with the leaders of the world's news agencies, held at the St. Petersburg Economic Forum, the RF President Vladimir Putin addressed the issue of the "Nord Stream" and "South Stream" gas pipelines. In particular, he expressed dissatisfaction with the actions of Brussels, which, in his words, "puts a spoke in the wheel" to the "South Stream" project and does not use the full capacity of the northern branch of the pipeline.