CBM: Coal Bed Methane

Imagine a sponge soaked in water, except the sponge here is a seam of coal deep underground, and the liquid trapped inside its pores is actually natural gas rather than water. Coal Bed Methane is exactly that, gas held within coal seams rather than in the more conventional rock reservoirs oil and gas companies usually drill into.

CBM extraction typically involves drilling into the coal seam and pumping out water to reduce pressure, which then allows the trapped methane to be released and captured, a meaningfully different process from conventional gas drilling. India has offered CBM blocks alongside some OALP and special bidding rounds, since several of the country's major coal belts also carry significant CBM potential that has historically gone untapped.

CBM remains a relatively small contributor to India's total gas supply today, but it is one of the unconventional resources, alongside shale gas, that policymakers keep returning to as a way of reducing the country's heavy dependence on imported gas.