Assessment of CO2 storage performance of the Enhanced Coalbed Methane pilot site in Kaniow

Assessment of CO2 storage performance of the Enhanced Coalbed Methane pilot site in Kaniow

van Bergen, F.
Winthaegen, P.
Pagnier, H.
Krzystolik, P.
Jura, B.
Skiba, J.
van Wageningen, N.
TNO Bouw en Ondergrond

2009

A pilot site for CO2 storage in coal seams was set-up in Poland, as has been reported on previous GHGT conferences. This site consisted of one injection and one production well. About 760 ton of CO2 has been injected into the reservoir from August 2004 to June 2005. Breakthrough of the injected CO2 was established, which resulted in the production of about 10% of the injected CO2 by the production well in this period. A follow-up EC project, MOVECBM, aimed at determining the storage performance of the reservoir, i.e. whether the injected CO2 was adsorbed onto the coal or whether it was still present as free gas in the pore space. The injection well was used for this purpose, because the production well had to be abandoned for permitting reasons. Several operational periods can be defined between the last injection in June 2005 and the abandonment of the well in October 2007. In the first period the well was shut-in to observe the pressure fall-off, followed by a decrease of pressure at the wellhead by releasing gas in a controlled way in the first months of 2006. The amount and composition of the gas were measured. As a result of the pressure reduction, the well flooded with water. A production pump was placed on the former injection well, enabling active production from the coal from March to September 2007. Results of these operations showed that whereas the gas production rates were as expected based on the experience with the production well, the water production was remarkably low. Further, the gas composition showed a predominance of CO2 over CH4 during the gas release that changed gradually into a predominance of CH4 over CO2 during the production phase. Although stabilization was not reached within the production period, the composition approached a 60% methane, 40% CO2 ratio. This indicates that the exchange of these gases is more complex than often envisaged. After removal of the pump the well was filled with water, which ceased the gas release. This indicates that the pressure in the reservoir was back to its original, hydrostatic, state. As the total volume of CO2 produced was only a fraction of the amount that was injected, it can be concluded that the CO2 was taken up by the coal and is currently adsorbed. This gives confidence in the long-term stability of the injected CO2. In conclusion, the field demonstration in Poland has been a successful experiment. Lessons learned in this demonstration indicate that the volumes that can be injected in low permeability coal seams (<2 mD) by a vertical well is likely to be less than 100 ton per day. The expected CBM production at these rates will be 1.5 to 2 times higher than by regular CBM operations because of the interaction with the CO2. It is recommended to perform ECBM operations as a secondary production phase after an initial CBM production phase. © 2009 Elsevier Ltd. All rights reserved.

Geological Survey Netherlands
Geosciences
General Energy / Geological Survey Netherlands
Carbon dioxide
Injection
Production
Swelling
Coal bed methane
Coal seams
Free gas
Gas compositions
Gas productions
Gas release
Injection
Injection wells
Lessons learned
Long term stability
Low permeability coal seam
Operational periods
Pore space
Pressure reduction
Production phase
Production wells
Secondary production
Storage performance
Vertical wells
Water production
Carbon dioxide
Coal
Coal deposits
Coal industry
Coal storage
Gases
Injection (oil wells)
Leakage (fluid)
Metal recovery
Methane
Oil wells
Pumps
Water injection
Well stimulation

http://resolver.tudelft.nl/uuid:de3ed739-1c16-47ef-b06a-03313805c783

https://doi.org/10.1016/j.egypro.2009.02.130

241387

1876-6102

Energy Procedia, 1 (1), 3407-3414

article