Related by context. Frequent words. (Click for all words.) 49 Coalbed methane 48 coalbed methane wells 47 Marcellus shale formation 47 naturally occurring mineral 47 nonproducing 46 sedimentary rock 46 contaminating groundwater 46 potent greenhouse gas 45 Horizontal drilling 45 shale formations 45 fracking fluid 45 Mesaverde 44 fracturing fluids 44 shale 44 saline aquifers 44 Greenland glacier 43 kerogen 43 frac sand 43 minable 43 redeposited 42 talus 42 shale deposits 42 coal seams 42 Brokered certificates 42 Chattanooga Shale 42 shales 42 earth crust 42 Paradox Basin 42 feet TVD 42 oxidise 42 insitu 42 Aquifers 41 Tar sands 41 rock formations 41 methane hydrates 41 Bakken shale formation 41 Engelder 41 decaying vegetation 41 fracked 41 Bakken formation 41 Marcellus Shale formation 41 geologic formations 41 porosities 41 deplete oxygen 41 glacial till 41 steam vents 40 mercury emitted 40 hydrocarbon molecules 40 hazardous liquids 40 Utica shale 40 undrained 40 sequester carbon dioxide 40 deposits 40 igneous rock 40 fumaroles 40 platinum palladium rhodium 40 uric acid crystals 40 Woodford shale 40 Mcfd 40 Hydrogen sulfide 40 hydrothermal fluids 39 dissolved solids 39 Raton Basin 39 Appalachian basin 39 sandstone formations 39 diatomite 39 rich Bakken shale 39 economically recoverable 39 FDIC insures 39 sandstone reservoirs 39 Pitzarella 39 Barnett Shale formation 39 extraction 39 loess 39 liquify 39 leasehold acreage 39 Athabasca oilsands 39 hydraulically fractured 39 cretaceous 39 dolomite 39 fracs 39 trona 39 liquified 39 geological formations 39 Coal seam 39 unconventional reservoirs 39 methane 39 carbonate rocks 38 Arctic permafrost 38 unstimulated 38 streambanks 38 placer deposits 38 clastic 38 drillers 38 Niobrara Shale 38 minerals 38 extractable 38 ° API 38 thicknesses ranging 38 methane CH4 38 magma chamber