The world's largest construction vessel, Pioneering Spirit, left Rotterdam port in the Netherlands on Friday and is now cruising to Black Sea in order to finish the deep-water construction of the second offshore line of TurkStream.
"Upon its return to the Black Sea, Pioneering Spirit will resume pipelaying of the second offshore string for TurkStream and will bring the second line to Kiyikoy in Turkey," Russian natural gas company Gazprom said on Friday in a statement.
"The vessel had completed the first line of TurkStream and laid the first 224 kilometers of the second line up until the the border of Russian and Turkish Exclusive Economic Zones," according to Gazprom.
The second line of TurkStream natural gas pipeline will have a capacity 15.75 billion cubic meters (bcm) per year and will carry Russian gas to European markets.
The route for the second line is not clear yet. Gazprom announced earlier that Greece and Bulgaria are both possible route options for the pipeline after it leaves Turkish border.
The construction of the first offshore line, which will carry Russian gas to Turkish market with a capacity of 15.75 bcm, was completed on April 30 this year.
Turkey's Energy and Natural Resources Minister Berat Albayrak, said earlier, that the project was planned to finalize before the end of 2019 by the close coordination and collaboration of the both parties.
"We came to an agreement that Turkey and Russia will complete the second line of TurkStream by the end of 2019," he said.
Russian natural gas company, Gazprom plans to deliver first batch of natural gas by December 2019 to Turkish shore Kiyikoy from Russian shore Anapa via TurkStream pipeline.
Following the completion of the first line of the project, Pioneering Spirit left the Turkish coast and headed for Rotterdam where the vessel was prepared for its next heavy-lift project - the installation of a 22,000-tonne drilling platform topsides for Norwegian Equinor's Johan Sverdrup development on the Norwegian continental shelf.
The Pioneering Spirit commenced offshore operations in August 2016 with the removal of a mobile production platform from Norwegian waters.
TurkStream is the vessel's maiden pipelaying project. It commenced deep-water pipelaying operations late June 2017 and up until April 30 was working exclusively for the TurkStream project.
By Baris Saglam in Moscow