The inert gas is not reactive with the methane or with the subsequently injected hydrogen and functions to reduce the methane partial pressure at {TAIL ~ a given coal bed total pressure} to promote {HEAD ~ methane desorption} 
The inert gas is not reactive with the methane or with the subsequently injected hydrogen and functions to reduce the methane partial pressure at { TAIL ~ a given coal bed total pressure } to promote { HEAD ~ methane desorption }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD