id	keyword
iogr-1274	� �
iogr-1274	gas
iogr-1274	pressure
iogr-1274	coal
iogr-1274	production
iogr-1274	block
iogr-1274	methane
iogr-1274	reservoir
iogr-1274	development
iogr-1274	coalbed
iogr-1274	content
iogr-1274	wells