CO2 Aquifer Storage Site Evaluation and Monitoring (CASSEM)

Carbon dioxide (CO2) is considered to be a greenhouse gas. The concentration of CO2 in the earth atmosphere is an important control on earth surface temperature, and hence climate. CO2 dissolution in the oceans is also being recognised as an important factor in making surface seawater unusually acid / this severely affects ecosystems and species from algae to fish and whales. Increased CO2 in the atmosphere is recognised as being partly caused by burning of fossil fuels, such as coal and gas, in power stations. Carbon Capture and Storage is a suite of technologies which enables CO2 to be captured at power stations, liquefied by increasing the pressure, transported by a pipe, and injected deep underground in to pore space of deeply buried sedimentary rocks such as sandstones. This can effectively remove CO2 from the power cycle of fossil fuel use, and store the CO2 for tens of thousands of years, which enables the earth atmosphere to return to normal. Because of the very large CO2 volumes involved, it is not possible to build surface stores. Because of the acid effects of CO2, it is not possible to inject CO2 into seawater. By contrast, the Intergovernmental Panel on Climate Change (IPCC) have calculated that more than 25% of world CO2 emissions could be stored by geological CCS. This could be a vital technology for the world’s future. There is a great deal of interest worldwide in CCS and, because of the offshore oil industry, the North Sea is one of the world’s prime areas for CCS to be rapidly developed. However, there are only three full-scale projects at present in the world. For UK power generating companies to become commercially interested the chain of technologies must be both demonstrated to work reliably, and must be capable of cost-effective development. This project is trying to identify aquifer sites deep underground which are close to power plant in the U.K., where CO2 can be safely stored, but sites are quicker and cheaper to develop than offshore in the North Sea. This can enable power generating companies to develop CCS over a period of years, on a medium scale, and learn to conduct the industrial operation. If this project is successful, it could lead to take up of CCS in the U.K. 10 or 15 years earlier than waiting for an infrastructure of large North Sea pipelines to be developed for CO2. When those pipes become available, UK power companies will be completely ready to connect power plant to store CO2 in large redundant hydrocarbon fields offshore. This could save many tens of million tons CO2 per year being emitted into the atmosphere from the U.K., and place the U.K. in the forefront of carbon reduction nations. The universities and companies involved in this 2.3M consortium are all experienced in investigating the deep subsurface for oil and gas production. Edinburgh, Heriot-Watt and BGS already have 1.6M from the Scottish Executive to establish the UK’s largest research grouping to investigate CO2 storage. This expertise will be transferred to exploring for CO2 disposal sites. Using the information held by the British Geological Survey, maps will be made of the subsurface deep beneath England, and deep beneath the Forth estuary. Heriot-Watt university will assess the potential chemical reactions of CO2 with rock, and how much CO2 can be injected. Electricity generators, led by Scottish Power, will make engineering designs for modified power stations to supply CO2. Schlumberger and Marathon Oil, will assess the subsurface technology required for safe and reliable injection and monitoring. The University of Edinburgh will make computer simulations to determine if CO2 will leak deep below ground, and will assess how specific site is storage sites will perform to safely retain CO2. Amec will evaluate transport of CO2 by pipe. Tyndall will investigate the public attitudes at the candidate storage sites.