Subsea 7 winds up its ‘largest float-over ever performed’

Luxembourg-domiciled Subsea 7 has completed its scope of work for the sailaway and offshore installation of a topsides unit for a BP-operated platform in Azerbaijan’s sector of the Caspian Sea.

This confirmation comes shortly after BP revealed it was closing in on the first oil from its Azeri Central East (ACE) project in Azerbaijan by completing the topsides sailaway and installation for the ACE platform. The platform is now ready for offshore hook-up and commissioning works in the Caspian Sea.

Subsea 7 underlines that its scope of work, which was completed in four days, encompassed sailaway, transportation, and float-over activities. According to the company, the ACE topsides platform, which weighs about 20,000 tonnes, is “the largest ever installed in the Caspian Sea and the largest float-over ever performed by Subsea 7.”

BP’s $6 billion ACE project is the next phase of the Azeri-Chirag-Deepwater Gunashli (ACG) field in the Caspian Sea off Azerbaijan. This project was sanctioned in April 2019 and construction started that same year with expectations to achieve the first production in 2023.

The ACE project has gas, oil, and water injection pipelines and all of them are now installed on the seabed. The pipelines range between 6 and 12 kilometres and tie into the existing ACG pipelines. The subsea oil pipeline isolation tool was launched and the works to isolate the pipeline topsides were also completed in the first half of 2023.

The ACE project, which is centred on a new 48-slot production, drilling, and quarters platform located mid-way between the existing Central Azeri and East Azeri platforms in a water depth of approximately 140 metres, entails new infield pipelines to transfer oil and gas from the ACE platform to the existing ACG Phase 2 oil and gas export pipelines for transportation to the onshore Sangachal terminal. 

The project also includes a water injection pipeline between the East Azeri and ACE platforms to supply injection water from the Central Azeri compression and water injection platform to the ACE facilities. The ACE platform and facilities are designed to process up to 100,000 barrels of oil per day while the project is expected to produce up to 300 million barrels over its lifetime.