Onshore CO 2 storage – description

The geological structures below are considered to be realistic options for onshore CO2 storage. See also section 1.3 for some informal comments on the maturity of the various potential storage sites.

Vedsted structure (storage capacity as published by GEUS: 162 Mt)

The structure is mature for further development, newer dense 2D seismic (2008) and an older exploration well on the structure itself, and another well off-structure is available.

Potential CO2 sources are located in the Aalborg area, requiring a 30 km pipeline comprising: Aalborg Portland (2.2 Mt/y), the city waste incineration plant and Nordjyllandsværket power plant for a total of maybe 3 Mt/y.

Other CO2 sources could be captured in other urban areas such as the Aarhus area requiring an approx. 100 km pipeline or could be imported by ship to a nearby port.

Gassum structure (630 Mt), Voldum structure (288 Mt) and Paarup structure (91 Mt)

The three structures could be developed as storage options for central eastern Jutland. These structures were a part of an extensive mapping exercise published by Japsen and Langtofte (1991). The Gassum and Voldum structures were evaluated by oil exploration wells. Transport from CO2 capture sites (power plants, CHP plants, waste-to-energy plants) to the storage site (1 Mt/y) in pipelines up to 1 Mt /y. Other CO2 sources could be imported by ship to a nearby port.

Havnsø structure (926 Mt)

A very large and promising structure mapped from old 2D seismic of low quality. The structure has not been drilled, and the geological interpretation is based on analogy from Stenlille natural gas storage structure.

Figure 0-17: Geological maps of the Havnsø and Røsnæs structures [18]

Potential CO2 sources are located in the Kalundborg area (0.5 Mt/Y) requiring a 20 km pipeline from port to the injection site. Other CO2 sources could be other urban areas such as the Copenhagen area, i.e. capture of CO2

from e.g. Amager Resource Centre, Amager power plant, HC Ørsted power plant, Avedøre power plant, Roskilde waste incineration plant and others along the route for a total of 3 to 5 Mt/y or maybe up to 7-8 Mt/y. This would either require a pipeline across Zealand or import by ship to gathering hub in the nearby Kalundborg port.

Generic onshore case

The generic case assumes some local CO2 capture in a port area, which can also be used for import of CO2 by ship. The port facilities will include an intermediate storage from where the CO2 is transferred to the injection plant through a 40 km pipeline.

1.1.1 1 Mt/year onshore CO² storage

CO2 is expected to be supplied to the port by shuttle tanker and stored in a 20,000 tonnes intermediate storage close to the port. The storage will consist of a number of well-insulated pressurised tanks where the CO2 is stored under the same conditions as in shuttle tankers (between -50˚C @ 6 barg and -30˚C @ 14 barg). A recov-ery unit will capture and liquify the CO2, which evaporates from the tank storage.

The CO2 is pumped from the storage tanks and heated with sea water and then transferred in a pipeline to the injection site where a high-pressure pump will increase the pressure to the required injection pressure to allow injection into the reservoir.

It is expected that the 1 Mt/y CO2 can be injected from one well pad with five wells, two for injection, one spare and two for observation.

Figure 0-18: 1 Mt/year Onshore storage facility 1.1.2 3 Mt/year onshore CO² storage

CO2 is expected to be supplied to the port by shuttle tankers and stored in a 30,000 tonnes intermediate stor-age. The CO2 is heated and pumped to the injection plant.

It is expected that the 3 Mt/y CO2 can be injected from three well pads with four wells each, six for injection, 2 spares and 4 for observation.

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Figure 0-19: 3 Mt/year Onshore storage facility 1.1.3 5 Mt/year onshore CO² storage

CO2 is expected to be supplied to the port by shuttle tankers and stored in a 50,000 tonnes intermediate stor-age. The CO2 is heated and pumped to the injection plant.

It is expected that the 5 Mt/y CO2 can be injected from five well pads with four wells each, 10 injection, 4 spare and 6 for observation.

Figure 0-20: 5 Mt/year Onshore storage facility

1.1.4 Typical timeline for an onshore CO² storage

Year Activity

1-2 Additional seismic surveys Appraisal well

Conceptual studies for facilities

3 Environmental impact assessment, public hearings and approvals FEED studies

Baseline studies

Final Investment Decision Land acquisitions

4-5 Establish CO2 terminal Construction of pipeline

Establish injection plant and well pads

Drilling of first injection and observation wells 6-7 Commence Injection CO2

Evaluation of reservoir behaviour

Investment decision for additional injection wells 8-9 Establish additional well pads

Drilling of additional injection and observation wells 10-35 Injection at nominal capacity

Continuous observation and seismic surveys , say every 5 years 36 Decommissioning of surface facilities, plug and abandonment of wells Up to next

20 years Continuous observation and seismic surveys Transfer of responsibility

Release of financial security Table 0-2: Typical timeline for onshore CO2 storage

It may be possible to accelerate the timeline shown above depending on the priority. Based on experience from other projects in terms of the permitting process, involvement of stakeholders and internal company approval to pass Final Investment Decision, the timeline presented here may seem shorter than what is realistic. But in view of the urgency of solving the climate problem and the need for reduction of CO2 content in the atmos-phere, the timeline presented here is an estimation based on the assumption that the required political support will be available to realise it.

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