AqualisBraemar LOC provided marine warranty survey (MWS) services for the marine construction campaign relating to the offshore section of the Trans-Anatolian Natural Gas Pipeline (TANAP pipeline), running at approximately 18 km long crossing the Canakkale Strait (Dardanelles) in the Sea of Marmara.
The subsea element of the pipeline comprised 2x 36 inch pipelines and 4x fibre optic cables. It involved pipelay activities at a maximum water depth of approximately 70 m.
The TANAP pipeline was built to transport gas from Azerbaijan’s Shah Deniz II field in the Caspian Sea to Europe.
Scope of Work
AqualisBraemar LOC worked on the project between 2016 and 2018 providing MWS services to review and approve marine operations relating to the offshore pipelay activities.
The scope included:
- Suitability surveys of the proposed support and construction fleet, including line pipe cargo barges, pipelay barges, dredgers, trenching vessels, diving vessels, rock dumpers, tugs and barges
- Review and approval of project documentation including calculations and analysis, drawings, procedures, certificates, manuals and relevant reports
- Onsite attendance to witness and approve warranted marine operations
- Carried out suitability surveys of 41 vessels
- Received and reviewed over 200 project documents
- Attended at marine operations across multiple global locations: Norway, Greece, Italy, Sea of Marmara, Dardanelles Strait Turkey
The location for the subsea pipeline presented unique challenges. These included that the pipelines and cables run across the Canakkale Strait, which is a main shipping route linking the Aegean Sea (Mediterranean) with the Sea of Marmara to the Black Sea. 2010 data shows that there were 50,000 vessels, including 5,500 oil tankers, passing through the straits annually.
In addition to this, landfalls for the offshore section of the pipeline are located in areas of high marine traffic. This meant, there was a need to synchronise installation operations with marine traffic through navigational risk analysis work.
The strait is also sinuous, varying in width with strong complex currents. AqualisBraemar LOC supported with metocean analyses to support in the planning of procedures and methodologies for pipe and cable-lay operations.
For more information, contact us to discuss how we can support your offshore pipeline operations.