Right First Time

Aquatic carousel makes its mark offshore Indonesia.

Two established trends in today’s subsea market are installations in deeper water and operations involving long tiebacks. Projects such as these require specialist equipment to accommodate the increasing length and weight of the flexible products required. Aquatic has responded to this need by developing and deploying a powerful modular carousel system that enables large, deepwater installation projects to use vessels of opportunity.

Aquatic’s new 1500-te carousel, the AQCS-01-1500, has completed its first commercial job: installing almost 10 km of continuous 8½-in.-diameter umbilical product from a vessel of opportunity, offshore Indonesia. The work in the South Belut field in the West Natuna Sea basin, which is about 130 km north-east of Singapore, was part of the ConocoPhillips Bawal Tembang and South Belut development project. The umbilical will enable production from three offshore fields in water depths of approximately 90 m.

The timing of the installation work, which was under contract to the development project’s engineering, procurement, construction and installation contractor, Kreuz Subsea, coincided with the completion of the design and construction of the carousel system in the UK. Keen to assess the effectiveness of its new system in the field, the Aquatic engineering team finalised the fabrication work and transported the carousel to Singapore in 30 shipping containers.

“We were delighted to secure the first commercial job so soon after finalising the carousel’s development programme,” explains Nick Dale, regional manager for Aquatic Asia Pacific. “We designed the AQCS-01-1500 to install heavy equipment in deepwater settings and handle product loads up to 1500-te. We knew it would significantly extend our installation capabilities and were looking for the chance to showcase its capabilities at the earliest opportunity.”

Aligning the carousel’s availability in Singapore with the proposed work-scope schedule was a challenge. To ensure that the carousel was ready in time for the South Belut project, Aquatic arranged for a site acceptance test at its facilities in Singapore then broke the unit down into four modular sections in advance of the vessel’s arrival to optimise the load-out process.

The AQCS-01-1500 carousel has a 12-m-diameter reel and a variable-diameter hub, which means that it can handle a range of products and can be mobilised onto most suitable vessels of opportunity. In this case, Aquatic and its client judged the fit to perfection. “The vessel chosen for the operation was the Seamec Princess diving support vessel. Once assembled and in place, the carousel filled the available deck space with the minimum clearance all round,” Dale says. The umbilical arrived at the quayside on three reels and the connections were made up and tested as the product was drawn onto the reel. The operation at South Belut was a significant learning opportunity but a task well within the limits of the system’s capabilities. “The project enabled us to assess the system and make minor adjustments in the light of field experience. This included the addition of extra padeyes on the carousel structure and taking more spare parts on-site,” Dale says.

Making the most of modularity
Unlike other commercially available innovations, the Aquatic carousel is modular and breaks down into components that fit into standard shipping containers. Transporting 30 containers by sea and assembling the system on a vessel of opportunity is significantly less expensive than mobilising a specialist carousel vessel and is much more flexible.

The prospect of using this carousel, along with Aquatic’s large deck tensioners, either individually or in tandem, and ancillary equipment, satisfies the market demand to enable clients to produce a complete spread capable of installations in deeper water and operations involving long tiebacks. All this helps to reduce overall project costs and timescales.

“The system is straightforward and quick to assemble and, crucially for our customers, offers a cost-effective alternative to buying a new carousel and building a vessel around it,” Dale adds. “The development process for this new carousel has drawn on all our previous engineering and operational experience, and underlines our commitment to providing services that meet our customers’ needs.”

Kurush Contractor, chief executive officer, Kreuz Subsea, says, “Working with Aquatic towards the successful completion of the project was a mutually supportive and efficient experience. The performance of the new carousel has exceeded our expectations and operations were completed ahead of schedule. We are already considering how we can work with Aquatic and its 1500-te carousel on future operations.”

Looking to the future, Dale anticipates significant opportunities for the AQCS-01-1500. “The carousel is currently in storage in Singapore and we are following up on potential opportunities offshore Asia and Australia. The carousel could be used for deepwater installation projects anywhere in the world, though there may be limited demand in West Africa where the installation market is dominated by specialist carousel vessels and there is less focus on managing operational costs. Eventually, we hope to have two carousel systems in operation: one based in South East Asia and the other serving the Americas, particularly the Gulf of Mexico.

“The success of the project at South Belut confirms the validity of our vessel-of-opportunity approach. We see these emerging opportunities and the prospect of further commercial work as rewards for innovative thinking and business insight. Aquatic’s understanding of the subsea installation market and drive to build the system as a commercial offering was only possible through Acteon’s investment in the programme,” Dale concludes.

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