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Transcript for The Future of Energy Gases, segment 06 of 13
Coalbed methane, a useful resource, was once seen only as a deadly threat to miners. At just the right mix with air at the slightest spark or flame, the gas explodes. Canaries once warned miners of dangerous gas concentrations.
More recently giant fans have been used to ventilate mines, greatly reducing the chance of explosions. Now coalbed methane is being captured for use as a fuel. In Alabama where coal is being mined underground, holes are drilled to the top of a coal seam long before a new mine section is open. Water is pumped from the coal to lower pressure and release methane. The gas moves to the surface where it's compressed and delivered to a pipeline. Capturing methane also lowers the hazard for mining that follows and reduces the quantity released into the atmosphere.
Methane is also produced from coals that are not mined underground. In northern New Mexico the La Plata Mine fuels the San Juan Power Plant, but fifteen miles east of the mine and several thousand feet below the surface, this coalbed delivers natural gas to wells that first tapped its potential in nineteen seventy-eight, becoming the first coalbed methane produced in the United States. Some seventeen hundred wells have now produced about forty billion cubic feet of natural gas from this coal.
Coalbed methane is a relatively new resource, and the amount ultimately available in the United States is uncertain. Our best estimates now indicate about ninety trillion cubic feet or a four to five years' supply added to our natural gas reserves.