A comparative assessment of transporting and unloading CO2 by ship

Summary

This programme found that a single design of ship and near-well installations could be used to inject CO2 into a variety of fields in the North Sea. This would make it possible to develop a uniform approach to storage in deep saline formations (which hold most of the storage capacity in the North Sea), oil fields (including the option to do enhanced oil recovery) and depleted gas fields. As storage reservoirs filled, systems could be transferred to the next location, to be reused, decreasing costs, enabling cooperation among different nations and so accelerating CCS development in Europe.

This study provides insight into the requirements for offshore offloading from ship to injection well for a range of potential storage sites in the North Sea. The results of the analysis are presented in terms of pumping and heating requirements to bring CO2 in a form suitable for ship transport to a condition acceptable for well injection. It covers capital and operational costs, but not offshore mooring and offloading options or possible temporary storage requirements.

Background

This project formed part of CATO, the Dutch national R&D programme for carbon capture, transport and storage involving a consortium of nearly 40 partners and comprising CATO-1, CATO-2 and now CATO-3. The last is funded by industrial partners and various government sources, including TKI, CLIMIT and EU ERA-NET. The CATO-2 programme, of which this project was a part, aimed to facilitate and enable the integrated development of CCS demonstration sites in the Netherlands.

Project objective

The goal of this programme was to evaluate the feasibility of taking a generic approach to developing a ship-based CO2 transport and storage system in the North Sea, using a range of typical North Sea reservoirs (offshore saline formation or hydrocarbon fields).

Project results

The cost of ship-based transport of CO2 is estimated to lie in the range of 13–33 €/t. The cost of ship-based transport in the North Sea is in the range of 13-27 €/tCO2 for a distance of 400km, increasing to 20–33€/tCO2 for a distance of 1200km.

Direct injection from a CO2 carrier into a range of typical injection wells is feasible. The equipment for compressing and heating the CO2 prior to injection can be installed on the ship and the power requirements are feasible. 

Temporary near-well storage is the lowest-cost solution offering shorter ship-offloading times and more efficient shipping fleet use. This reduces overall costs relative to direct injection from the ship into the well.

The results suggested that limited modifications to platforms would be required to inject the CO2, but this would need to be assessed for each injection location.