ACE topsides installation; Source: Mammoet

Mammoet done with jacking, load-out and float-over job for BP’s Caspian Sea platform – gallery

Dutch heavy lifting and transport provider Mammoet has performed jacking, load-out and float-over operations for a 19,600-tonne offshore platform topsides unit destined for BP’s project in the Caspian Sea, offshore Azerbaijan.

ACE topsides installation; Source: Mammoet

The construction of the 19,600-tonne topsides unit for the Azeri Central East (ACE) platform started in 2019 and was completed with safety achievements of over 21 million hours worked injury-free. The ACE topsides unit consists of oil and gas processing facilities, an integrated drilling rig, a gas compressor, and living quarters. The topsides unit was constructed by Azfen in the Bayil fabrication yard using local infrastructure and resources.

Back in December 2022, the jacket of the Azeri Central East platform – built at the Heydar Aliyev Baku Deepwater Jackets Factory (BDJF) – was ready for load-out to sail away to its permanent location in the ACG contract area in the Caspian Sea. Afterwards, the topsides unit was jacked up and lowered onto the load-out frame in preparation for skidding onto the transportation barge STB-1, which arrived at the Bibi-Heybat yard in May 2023. A few days later, the topsides unit was transferred onto the STB-1 barge, sea-fastened, and prepared for sailaway to the ACG field.

The Azeri Central East platform topsides unit sailed away on 7 August 2023 from the Bayil fabrication yard where it was built. Prior to its sailaway, the topsides unit was mostly commissioned and operationally tested onshore to minimise the activities required for offshore installation and start-up. The unit was installed on top of the ACE platform jacket, which has been at its offshore location since March, installed in a water depth of 137 metres.

According to Mammoet, its engineering and innovative equipment delivered “safe and efficient” load-out and offshore installation operations for the Azeri Central East production, drilling and quarters (PDQ) platform. The company’s scope of work included the weighing, jack-up, load-out, and float-over installation operations of the production, drilling, and quarters platform.

Leveraging its engineering capabilities, Mammoet ensured the transfer of the platform topsides from the quayside onto the transportation barge STB-1 and subsequently onto the jacket foundation offshore. At the quayside, the topsides unit was jacked up to a height of 17 metres and then gently lowered onto a custom load-out support frame, utilising the Dutch player’s largest jacking system, Mega Jack 5200.

The unit was then skidded onto the barge, where it was sea-fastened and prepared for its voyage to the Azeri-Chirag-Deepwater Gunashli (ACG) field. The skidding operation onto the barge’s deck was accomplished using four 900-tonne strand jacks, break-out jacks, a high-capacity ballast system, load monitoring quay jacks comprising of six 600-tonne jacks, and mooring winches.  

Upon its arrival at the designated field location, Mammoet executed the installation of the topside unit onto the jacket foundation through a float-over operation. The barge was positioned over the substructure and the topsides unit was then lowered onto the substructure while maintaining the barge’s position.

The Dutch firm explains that the barge’s internal ballasting and winching system was enhanced with its float-over winches and configurable high-flow rapid ballast system, enabling an additional flow capability of approximately 32,000m3/hr. As a result, this “centrally controlled and monitored ballast system ensured real-time oversight, guaranteeing operational continuity and a safe float-over process,” outlined Mammoet.
Moreover, the company says that it played “a key role” in the integration of the platform’s DES and MDSM modules, totalling 2,400 and 2,350 tonnes respectively, showcasing its multi-faceted capabilities. Looking ahead, the company reveals that drilling is expected to start in the coming months while the delivery of ACE’s first oil is anticipated in early 2024.
Dan Kempin, Business Development Manager for Mammoet, commented: “As we continue to redefine industry standards through our innovative solutions and steadfast commitment to safety, the successful load-out and float-over operations of this massive topsides unit stands as a testament to Mammoet’s dedication to excellence in engineered heavy lifting and transport.”

Subsea 7 also worked on this project and its scope of work, which was completed in four days, encompassed sailaway, transportation, and float-over activities. 

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BP’s $6 billion ACE project is the next phase of the 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 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.

The project 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. In addition, the project will include 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. At peak, over 8,500 people were involved in the ACE project construction works in Azerbaijan.

Mammoet also recently participated in the delivery of several topsides and jackets from three North Sea platforms to Port of Blyth. These were removed by Heerema Marine Contractors’ second-largest semi-submersible crane vessel (SSCV), Thialf.