The TurkStream pipeline system that will transport Russian gas across the Black Sea to Turkey has achieved a key milestone with the completion of its offshore section.

Russian state-owned oil and gas company Gazprom is building the TurkStream project with two 930km-long parallel offshore pipelines with a combined capacity of 31.5 billion cubic metres of gas a year.

While the first pipeline will deliver gas to Turkey, the second will cater to European countries.

Gazprom subsidiary South Stream Transport handled the construction of the offshore section, while the contract for both pipelines was awarded to Allseas Group.

Allseas deployed the Pioneering Spirit pipelaying vessel to complete the construction.

“The offshore section of the gas pipeline was completed as early as today instead of in December as planned earlier.”

A ceremony was held to mark the completion of the offshore section.

Turkey President Recep Tayyip Erdogan and his Russian counterpart Vladimir Putin attended the event and gave the command to weld the final joint of the second line of the gas pipeline.

Gazprom Management Committee chairman Alexey Miller said: “Construction of TurkStream, a new gas pipeline connecting Russia and Turkey via the Black Sea, is entering its final stage.

“The work is well ahead of schedule: the offshore section of the gas pipeline was completed as early as today instead of in December as planned earlier.”

Miller added that the pipeline will ensure energy security in Turkey and the countries of southern and southeastern Europe.

Gazprom expected to bring the gas pipeline into operation by the end of next year. The project work will now include the onshore section.

The offshore pipelines will start near Anapa, on the Russian coast, and end on the Turkish coast, around 100km west of Istanbul.

Turkey’s state-owned pipeline operator Botas will build the pipeline’s onshore section, which will carry the gas from the coast to the Luleburgaz distribution centre.