Russia is likely to maintain some gas transit through Ukraine even if
 Turkish Stream and Nord Stream 2 pipelines are built, energy expert 
	Peter Poptchev told New Europe.
"Russia would not mind transiting ‘some’ gas through Ukraine – after 
it would have realised – if at all – Turkish Stream and Nord Stream 2,” 
said Poptchev, who served as ambassador-at-large for energy security at 
the Bulgarian Ministry of Foreign Affairs when the Balkan country 
negotiated the now-cancelled South Stream pipeline with Gazprom.
Russian President 
	Vladimir Putin and Gazprom are 
pushing instead its Turkish Stream pipeline, envisioning the 
construction of two underwater legs of the gas pipeline in the Black 
Sea. The annual capacity of each leg is estimated to reach 15.75 billion
 cubic metres of natural gas. Pipe-laying work for the Turkish Stream is
 expected to begin in 2017 and end in late 2019. Turkish Stream is 
expected to deliver gas from Russia to Turkey and continue to a hub on 
the Turkish-Greek border, from where the gas could be transferred across
 Greece to Italy.
Poptchev said that the first reason Russia would keep transiting gas 
through Ukraine is to keep, and if possible, increase, Gazprom’s market 
share in Europe.
The second reason is to utilise the Trans-Balkan Pipeline (TBP) in 
order to limit or prevent shipment of Southern Corridor gas or liquefied
 natural gas (LNG), or East Mediterranean gas north through Greece and 
Bulgaria through TBP.
The third reason is for Moscow to keep influence on Kiev, just in 
case, he said. "For once, Mr. Putin is honest about shipments based on 
market demand, just because he believes that slowly but surely he had 
succeeded to build the bases for both Turkish Stream and Nord Stream 2,”
 Poptchev said.
https://www.neweurope.eu/article/even-turkish-stream-nord-stream-2-russia-will-keep-ukraine-gas-loop/