Stress emission of helium and argon in coal seams

In the Yutianbao Mine, the Nantong Coal Field, Chongqing, a lot of gas samples were measured and analyzed. It has been found in these samples that helium is sensitive to stress concentration, while argon is sensitive to stress release. Compared with the flowing out of gas itself, the combination of helium and argon can be more suitably used as an indicator to predict gas outburst. In a mining area of this mine, both δ He > 30 and δAr < δ0.97="" can="" be="" used="" critically="" to="" define="" the="" dangerous="" area.="" also,="" the="" contour="" maps="" of="" δ="" he,="" δ="" ar="" and="" ch4="" can="" provide="" a="" guidance="" for="" engineering="" monitoring.="">