Carbon Capture and Storage – A Roadmap for Scotland
in the Scottish Parliament to ensure the development of a regulatory framework for the storage of carbon offshore. The Scottish Government continues to work with the UK government, DECC, SEPA and others to develop a policy regulatory framework for the development of CCS projects.
Scottish Ministers have responsibility for licensing from 0-12 nautical miles in Scottish territorial waters (the point of injection is the important point to consider) while UK ministers have responsibility for the area from 12-200 nautical miles. However a memorandum of understanding between UK and Scottish Ministers is currently being agreed so that in the latter area, Scottish Ministers will be consulted in the process of issuing a storage licence and vice versa. The actual licensing of CO2 for storage in the Scottish territorial sea will be undertaken by Marine Scotland. Onshore storage is also permitted under the EU Directive, but the Scottish Government does not foresee any such development here in the short to medium term, where the focus will be on the offshore area.
In the short-term, depleted oil and gas fields in the North Sea are the most likely and ready storage sites for carbon.
The level of knowledge and information about these oil and gas fields is understandably higher than for saline aquifers. There may also be some opportunity for the use of carbon dioxide for Enhanced Oil Recovery (EOR), which can increase oil production levels, although, as the Scottish study stated, there are a number of technical and cost issues which need to be considered before EOR can be developed in the North Sea.
However the research study indicated that in the longer term, saline aquifers are likely to provide the greatest storage potential in the North Sea. The Scottish Government is already committed in the short term to contributing to the funding of the successor project, the Scottish CCTS Development Study, which will focus on commencing the more detailed assessment of selected saline aquifers in order to refine their CO2 storage capacity and efficiency and also the safety case and environmental assessment for the CO2 store.
Such studies are important and in the medium to long term an essential precursor to much more detailed and expensive aquifer assessment from newly acquired data including drilling. The costs of aquifer assessment are high and the final sum is likely to be similar to that for appraisal of hydrocarbon fields. As yet the prospects for further exploration, without some sort of regulation certainty or financial incentive are somewhat uncertain. There is an intrinsic linkage between developing projects at the capture end of the chain with the development of proven storage capacity.