• What is coal bed methane?

Methane is the primary energy source of natural gas. Coal bed methane (CBM) is the methane gas found in coal seams. According to the International Energy Agency (IEA), by 2030, coal-based power generation is projected to more than triple. Despite competition from natural gas, coal is likely to provide 33 per cent of global electricity generation. Over 58 per cent of the world’s recoverable coal reserves are located in the United States (27 per cent), China (13 per cent), India (10 per cent) and Australia (8.7 per cent). And all these countries are now looking at exploring for CBM. Currently, natural gas from coal beds accounts for approximately 8 per cent of total natural gas production in the US. The resource potential of CBM in India has been conservatively estimated at 850 billion cubic metres. Methane is seen as an alternative gas for meeting local gas needs. As India’s gas demand rises, CBM and coalmine methane (CMM) will be able to compete favourably with imported coal, gas, or LNG on a fuel cost basis for power generation. From an environmental standpoint, use of CBM also makes sense. India’s heavy reliance on coal, much of it low quality, is a major cause of the country’s air pollution and relatively high carbon intensity level.

• How is amount of methane gas in a region estimated?

One method of estimating recoverable methane gas from a coal seam is estimating methane reserves by boring to the top of the coal seam, then extracting a core from the coal. The amount of methane recovered from the coal core is used to estimate gas content per unit volume of coal. If a number of cores are drilled and methane gas release is observed, one can estimate the amount of gas available in a region. The other method is through a series of calculations based on information already known about the coal in the region and the feasibility of CBM development.

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