Geochemical investigation of hydrocarbon generation potential of coal from Raniganj Basin, India

Abstract

Methane content in a coal seam is a necessary parameter for evaluating coal bed gas, and it poses an environmental risk to underground coal mining activities. Keeping in pace with comprehensive studies of coal bed gas, 12 coal samples were selected from the Sitarampur block of Raniganj Coalfield for analysis. The Petrographic examination illustrated that significant values of reactive macerals present in samples demonstrate that organic matter is dominated by the prominent source of aromatic hydrocarbons with a minor proportion of aliphatic hydrocarbon, which falls in the region of (Type III) kerogen, confirms the suitability for the potential of hydrocarbon generation. “A” factor (aliphatic/aromatic bands) and “C” factor (carbonyl/carboxyl bands) value concluded that the sample has the lowest aromaticity and the highest hydrocarbon-generating potential, which was also validated by the Van Krevelen diagram. The Van Krevelen diagram plots between the H/C and O/C ratio indicate that coal samples lie in the type III kerogen, and bituminous coal (gas prone zone) is present in the block, which is confirmed by the cross-plot between desorbed and total gas (cc/g). The in situ gas content values are high enough to produce methane from coal beds. The overall study concludes that the Sitarampur block from Raniganj Coalfield is suitable for hydrocarbon generation and extraction.

Modeling and Forecasting of Coal Bed Methane Reservoir from Raniganj Coalfield, India

“…Methane concentration in virgin coal bed methane (VCBM) is generally very high (>90%), which makes it eventually an additional source for natural gas supplies [15][16][17][18][19][20][21][22][23]. Methane gas, released during the mining activity and therefore released into the atmosphere by the ventilation system, is known as ventilation air methane [24].…”

“…The coal basins present in India are divided into four categories according to their area, geological age, coal quality, gas resource and depth of coal occurrence, as shown in Figure 1 [40]. Raniganj coalfield is one of the largest coalfields, and the coal seams present in this area are thick and carry high-rank bituminous coal with the considerable resource of coal bed methane [15][16][17][18][19][20][21][22]. One virgin coal block from Sitarampur located in the Burdwan district of West Bengal was being explored by Mineral Development and Trading Corporation Limited, Kolkata.…”