New York Times: Jin Peisheng, a drilling rig foreman, knows the challenges of trying to extract natural gas from a coal seam under the cornfields here in north-central China.
Cracks in the subterranean coal are flooded with water that needs to be pumped out before the gas will emerge. The coal seams are so cold that gels injected into the well, which are meant to help release the gas, sometimes become gummy and block the flow instead. And there is constant concern about hitting the labyrinths of active coal mines...