Since 1973, Russian geological team of Vost NII Institue has been identified methane content in Nalaikh old coal mine determined 5-10 m3/tn. Dec of 1990, In 5th coal seam of west part of mine has been determined higher methane content 15 m3/tn. In mining history of Nalaikh old coal mine has been happened 3 signigicant methane explosions.
In the 1950s (Dashjamts) II, IY, Y and YIII coal seams of Nalaikh old coal mine, weighing up to 30-60 kg mass were tested for semi-coking. According to this test, the primary coal resin yield - 5.7%, semi coke- 62,3%, the initial gas output is 90.9 liters per kilogram of coal. Gas mixtures of gas combustible products - 44.0%, carbon oxides -39.0%, nitrogen- 15%, various resin lighter oils - up to 60.0%.