Facets of coalbed methane reservoir in East Bokaro Basin, India

The East Bokaro Basin of the Damodar valley is a potentially prospective CBM (coalbed methane) play having significant cumulative coal seam thickness, in-situ gas content, vitrinite percentage, and adequate thermal maturity. Successful recovery needs detailed understanding organic pore structures/networks, storage properties flow mechanism. present work attempts to systematically investigate for organo-petrographic controls on content generation, variations in sorption capacity saturation, mechanisms, cleat intensity, aperture distribution spacing. values gas, methane concentration (C1) vary from 3.52 30.93 cc/g (dry ash-free basis), 15.40–32.40 66–93 vol%, respectively. atomic ratios H/C O/C indicate that thermally matured seams contain type III-IV kerogen positioned dry window. decrease hydrogen-containing liptinite with increasing depth reveals function gradient cracking liptinitic compounds successive evolution hydrocarbons development carbon-rich matrix. ratio also influenced by reflectance deeper coal. More than 63 % desorbed was determined desorption measurement low time (?, mainly <10 days). This demonstrates good diffusion characteristics studied It shows tendency pores reaches cleat-fractures negligible influence secondary mineral infillings. high-pressure studies various samples substantial open-pore characteristics, supporting adsorption, release. relationship C3/C1 C2/C1 primarily originated thermogenic transformation matter. Such an assessment supported stable isotope (?13C1) value ranges between ?22.70 ‰ ?57.30 ‰. However, some lighter (<–50 ‰) mixed origin gases, which may be due influx fresh-water associated aquifers carrying bacteria received local drainage. Geochemically altered dissolved partially filled pores, shown SEM photographs, negligibly sorption, diffusion, mechanism coalbeds. network model signifying are microstructurally different comprises lateral difference cleat/fracture.