Experimental and analytical studies on permeability reduction of coal seam by CO2 injection

Ferian Anggara, Kyuro Sasaki, Yuichi Sugai

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Permeability of coal seam have a strong effect on CO2 Enhanced Coal Bed Methane Recovery(CO2-ECBMR) project. In particular, qualification of permeability reduction due to coal matrix swelling is a key parameter to control CO2 injection and the project sustainability. Swelling experiments using visualization method were conducted. Crushed samples from Indonesia Low Rank Coal (LRC) were used and the experiments were carried out up to 10 MPa at 48° C temperature, resulting CO2 in the supercritical conditions that more appropriate for CO2 injection in the field. Coal swelling which was represent by upward surface movement of column was assumed as total expanded volume for each particle. With this assumption, crushed samples were modeled like block coal samples. For three coal samples, the maximum expanded volume due to the swelling by CO2 adsorption has been evaluated as 0.03 at 10 MPa pressure. Since the swelling results were very comparable to others, this method has more advantage in term of sample preparation and experiment work compare to block coal. Based on the present swelling data, two analytical models proposed by Palmer and Mansoori (P-M) and Shi and Durucan (S-D) have been applied to Yubari field test. Permeability reduction (k/k0) ratio by CO2 swelling in the test has been estimated as 0.021 to 0.056 for the coal seam condition of 10 and 15 MPa of initial formation and injection pressures, respectively. Sasaki et al.15 proposed analytical radial flow model to evaluate CO2 swelling ratio (β). The swelling ratio on permeability has been evaluated as β = 0.020 to 0.044 and original coal permeability k0 ≈ 3 md by matching with monitoring data measured in the field. Both values of k/k0 and β have shown extremely good agreements. Furthermore, initial permeability of the coal seam was also proved by fall-off data. Thus, it is concluded that the CO2 injection rate can be expected by the models showing relationship between porosity, permeability and swelling of coal.

Original languageEnglish
Title of host publicationInternational Petroleum Technology Conference 2011, IPTC 2011
PublisherInternational Petroleum Technology Conference (IPTC)
ISBN (Print)9781613991480
Publication statusPublished - Jan 1 2011
EventInternational Petroleum Technology Conference 2011, IPTC 2011 - Bangkok, Thailand
Duration: Nov 15 2011Nov 17 2011

Publication series

NameInternational Petroleum Technology Conference 2011, IPTC 2011


OtherInternational Petroleum Technology Conference 2011, IPTC 2011

All Science Journal Classification (ASJC) codes

  • Geochemistry and Petrology
  • Geophysics
  • Geotechnical Engineering and Engineering Geology
  • Fuel Technology


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