1 Carbon Capture and Storage Martin Blunt Department of Earth Science and Engineering Imperial College London

Carbon Capture and Storage Consortium UK, UKCCS

Geological storage of carbon dioxide Greater than 20 Gt in North Sea alone (Gibbins et al, 2006)

Why geological storage? Technology already established – many carbon dioxide injection projects in the world. Allows smooth transition away from a fossil fuel economy. Economic benefit of enhanced oil recovery. Has potential to have a large impact on carbon dioxide emissions quickly. Low emission option for developing countries – e.g. China and India who will invest in coal-burning power stations anyway.

Why geological storage? – China China is now the world’s largest CO 2 producer, 6.2 billion tonnes in 2006 – Netherlands Environmental Assessment Agency. 70% of China’s power is derived from coal; they use 39% of world production. Currently building 550 coal-fired power stations; electricity generation rose 150% This will happen whether we like it or not. We have to offer a technology that prevents the CO 2 generated reaching the atmosphere.

Current projects – planned or underway

Current oil field projects 66 CO 2 injection projects worldwide. Mainly in Texas. Uses natural sources of CO 2 from underground reservoirs. Extensive pipeline infrastructure – thousands of miles. North Sea plans in Miller (BP) and Draugen/Heidrun (Shell/Statoil)

Sleipner project 1 million tonnes CO 2 injected per year. CO 2 separated from produced gas. Avoids Norwegian CO 2 tax. Gravity segregation and flow under shale layers controls CO 2 movement.

Some numbers Current emissions are around 25 Gt CO 2 per year (6 Gt carbon). Say inject at 10 MPa and 40 o C – density is 700 kgm -3. This is around 10 8 m 3 /day or around 650 million barrels per day. Current oil production is around 80 million barrels per day. Huge volumes – so not likely to be the whole story. Costs: 1-2p/KWh for electricity for capture and storage; £25-60 per tonne CO 2 removed – Shackley and Gough, Could fill the UK emissions gap in 2020 easily; but lukewarm Government support (300 MW plant by ) has killed potential lead in this.

10 20% by % by 2050

Issues to address Major cost issue: how to separate carbon dioxide from the exhaust stream of a coal or gas-burning power station efficiently; current amine scrubbers are inefficient. Major public acceptance issue: how to ensure that the CO 2 remains underground. Chemical Engineering: membrane and solvent separation. Earth Science & Engineering: design of injection to trap CO 2. Mechanical Engineering: policy and UKCCS coordination.

12 Long-term fate How can you be sure that the CO 2 stays underground?  Dissolution – CO 2 dissolves in water – 1,000-year timescales  Chemical reaction – carbonate precipitation – 10 3 – 10 9 years  Trapping – rapid (decades): CO 2 as pore-scale droplets surrounded by water. Design this process. 1 mm 1 km

13 Design of CO 2 injection Inject CO 2 and water together – water comes from the aquifer – followed by water injection. This renders the CO 2 immobile. Fractional flow of carbon dioxide

14 Simulation results producer injectorproducer Permeability distribution for SPE 10 Plot of the amount of CO 2 injected, CO 2 trapped and CO 2 produced. Plot of the cumulative oil production for WAG (water alternate gas) injection and water injection.

15 Results and future work  In the Maureen field, CO 2 and water injection increased oil recovery by 5-10%.  This represents up to $2 billion of revenue from increased oil production while storing over 55 million tonnes of CO 2.  This is equivalent to the total CO 2 produced in a year by over 5 million people in the UK or the equivalent of all the CO 2 produced from all activities from the population of London in a year.  In the future, these strategies could be applied to other North Sea fields (e.g. BP’s abandoned Peterhead/Miller project) and the technology exported worldwide.  Continue to work on a design strategy to render CO 2 immobile.

Overview Carbon capture and storage is a key component to reduce atmospheric CO 2 emissions. UK has a strategic opportunity to take a lead in CCS. Unique combination of fossil-fuel burning power stations close to oil fields ripe for CO 2 flooding plus pipeline infrastructure. Need to predict where the fluid moves (charactersiation and simulation), design injection strategies, monitor where the fluid moves (4D seismic) and assess long- term fate (trapping).

Thanks Lynn Orr (GCEP, Stanford University) and Jon Gibbins (Imperial) for slides and useful insights. E I Obi (now at Total) and Ran Qi the PhD students who did the work. Shell for funding under the Grand Challenge in Clean Fossil Fuels