Organo-petrographic and pore facets of Permian shale beds of Jharia Basin with implications to shale gas reservoir

Autor: Sujeet Kumar, Atul Kumar Varma, Durgesh Kumar, Vinod Atmaram Mendhe, Alka Damodhar Kamble, Harpal Singh, Mollika Bannerjee, Ranjit G. Khangar, Subhashree Mishra
Rok vydání: 2017
Předmět:
Zdroj: Journal of Earth Science. 28:897-916
ISSN: 1867-111X
1674-487X
DOI: 10.1007/s12583-017-0779-8
Popis: The shale deposits of Damodar Valley have received great attention since preliminary studies indicate their potential for shale gas. However, fundamental information allied to shale gas reservoir characteristics are still rare in India, as exploration is in the primary stage. In this study, Barakar shale beds of eastern part of Jharia Basin are evaluated for gas reservoir characteristics. It is evident that Barakar shales are carbonaceous, silty, contains sub-angular flecks of quartz and mica, irregular hair-line fractures and showing lithological variations along the bedding planes, signifying terrestrial-fluviatile deposits under reducing environment. The values of TOC varies from 1.21 wt.% to 17.32 wt.%, indicating good source rock potentiality. The vitrinite, liptinite, inertinite and mineral matter ranging from 0.28 vol.% to 12.98 vol.%, 0.17 vol.% to 3.23 vol.%, 0.23 vol.% to 9.05 vol.%, and 74.74 vol.% to 99.10 vol.%, respectively. The ternary facies plot of maceral composition substantiated that Barakar shales are vitrinite rich and placed in the thermal-dry gas prone region. The low values of the surface area determined following different methods point towards low methane storage capacity, this is because of diagenesis and alterations of potash feldspar responsible for pore blocking effect. The pore size distribution signifying the micro to mesoporous nature, while Type II sorption curve with the H2 type of hysteresis pattern, specifies the heterogeneity in pore structure mainly combined-slit and bottle neck pores.
Databáze: OpenAIRE
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