Development of a connection solution with a focus on a control system (umbilical) for controlling wells from ships for use with direct injection of CO₂ from ships

Background
Nemo Maritime AS, together with its industrial partners; Framo, Worley-Rosenberg, Brevik Engineering and NORCE, has developed a concept for ship transport of liquid CO₂ with direct injection into storage reservoirs. The project was carried out in the period 2021–2024 with support from the Research Council of Norway as an Industry Project Business (IPN). The results include ship design with cargo tanks for CO₂, transfer pumps and design of the process unit fully integrated for injection into the reservoir. NORCE performed a thorough study of the reservoir effects of batch (interval) injection to qualify the concept. This project ran over 3 years from 2022-2024 and included extensive reservoir work carried out by NORCE to study the effects of interval-based CO₂ injection. Based on experience with piped injection from the Sleipner field and the Snøhvit field, it has been assumed that continuous injection works best. However, this has not been studied previously, and it was a knowledge gap that NFR believed was important to fill with new knowledge.

To complete a direct injection solution, it was necessary to develop solutions for connection between ships and injection wells through an unloading solution. This was carried out in CLIMIT Demo project 623318 which carried out concept studies for unloading systems for direct connection to wells.
What remained to have a complete injection solution was to develop a well control solution to be able to control the injection wells from the ship through a cable that can be connected to and from the ship, together with the unloading hose.

In addition, we have seen that high injection rates are beneficial for reducing the costs of ship injection. There was therefore a need to increase the pump capacity of the pumps that will be located in the storage tanks, which Framo AS has developed.

Together with OneSubsea-SLB AS and Framo AS, a consortium was established that applied for project support from CLIMIT Demo, which was granted in June 2026.

Goal
The project aim was to develop solutions for control cables and control systems for direct control of injection wells from a transport ship for CO₂. The project builds on the solutions from the previous study of developing unloading solutions for direct injection of CO₂ from a transport ship to injection wells on the seabed. The solutions must have a simple and robust connection solution so that the ships can come and go without time-consuming connection operations. In addition, the systems must be reliable with good procedures so that the system can be approved by the authorities.

In addition to developing control cables, a concept design was also carried out to double the injection rate compared to previous designs and improve energy-efficiency of the pumps. Solutions for parallel connection of pumps to be able to inject into several wells simultaneously will also be investigated. This is particularly relevant when unloading to storage tanks which will make the ships very flexible to serve different transport needs.

The goal has been to obtain a complete technical solution to be able to perform direct injection with control of the injection wells directly from the ship, thereby avoiding establishing separate control systems on land or being dependent on manned platforms.

Activities
Development of well control has consisted of the following activities:

1. Develop conceptual design to transfer CO₂ and signals for well control between a ship and the seabed, when
a. the ship is passively anchored via a buoy or anchored,
b. The ship uses dynamic positioning.
2. Develop functional solutions for connecting and disconnecting control cable and discharge hose.
3. Assess effects of CO₂ on material qualities in the solutions
4. Develop safety systems and procedures for emergency disconnection

Concept development for doubling pump capacity from 250t/h to 500+ t/h has consisted of the following activities:

1. Conceptual design of a pump with a capacity of 500 tons per hour
2. Possibilities for parallel injection in multiple wells with interconnection of pumps
3. Optimization of pumps with regard to power consumption and flexibility.

Results
The project results reflect the goals that were set for the project:

1) Concept solutions for control cable, a solution has been developed for well control and cable solution that can be left in the sea when the ship is in transit, picked up and connected to the ship when it arrives at the location. The results show that the solutions are technically feasible, and demonstrate that it is entirely possible to perform well control directly from the ship. No technical obstacles have been identified to implementing these solutions. Most components are based on existing technology, but some components require adaptation to use with CO₂.

2) Framo has developed a larger pump and evaluated various configurations to enable higher-speed offloading. This offers greater flexibility in terms of servicing various storage sites currently under planning, in combination with direct offshore injection. In this way, we can reduce storage risk and, consequently, the need for contingency margins and liability coverage should reservoir issues arise at one of the storage sites. Analyzing pump efficiency is crucial when selecting the design and configuration for the pumps.

Further Work
Based on the results from this phase, the project should proceed to the next phase, emphasizing further engineering and system integration. The primary focus should be on maturing the connection system (J-plate system), finalizing material selection, and designing for robust, repeatable offshore operations. A key task will be analyzing the entire control chain, extending from the vessel’s control room to the subsea well. Further studies regarding the onboard process plant for CO₂ conditioning will also be required.

The work completed in Phase 2 provides a solid foundation for moving forward. The concept utilizes proven technology, presents no technical obstacles, and can be developed into a fully qualified and reliable system for the CO₂ pilot project. Future work will focus on detailed engineering, component qualification, system integration testing, and advancing the system’s maturity to a level suitable for field deployment.

The loading pumps have been tested with liquefied gases such as ammonia and LNG. Based on operational experience, the original design has been modified to enhance operational reliability. A test facility has been constructed to test the pumps with liquid CO₂; however, execution has proven challenging due to HSE requirements and difficulties in sourcing sufficient quantities of CO₂. Efforts are underway to resolve this and ensure the pumps are validated prior to fabrication.

Publications
Scientific or popular science publications.
The Nemo ship concept, including offloading solutions are included in the Carbon Transport Solutions (CETP) project report to be published late 2026, and will be presented at the Baltic Forum 2026.

Technology Readiness Level (TRL)
Increase in technological maturity (TRL) from project start.
During this study phase, OneSubsea-SLB has developed a scalable concept for transmitting control signals between the vessel and the well. The solution relies on proven components for signal and hydraulic transmission; however, the integrated system solution has so far only been evaluated through design work and technical studies. The concept is therefore rated at TRL 5, with the next step being the construction of a prototype and verification testing to achieve TRL 6.
Framo’s pumps are at TRL 9 for LNG applications and TRL 6 for CO₂, as testing in liquid CO₂ remains to be completed.

Intellectual property rights (IP)
Establishment or clarification of intellectual property rights (IP), including patents, licensing or other formal rights structure.
Nemo have been awarded patents for their ship solution in Norway, Europe, USA and Australia.

Links
To web-pages.
Nemo: www.nemomaritme.com
Framo: www.framo.com
OneSubsea: www.onesubsea.slb.com