Gas activity analysis in the ground

Abstract

A method of introducing a propellant gas into the ground is described, wherein a trace gas that can be analysed above the ground or the earth's surface is added to said propellant gas. According to the invention hydrogen is used as the trace gas, whereby the proportion of the trace gas hydrogen in the propellant gas/trace gas mixture is a maximum of 10% by vol., preferably a maximum of 5% by vol.

1 . A method of introducing a propellant gas into the ground, wherein a trace gas that can be analysed above the ground or the earth's surface is added to said propellant gas, characterised in that hydrogen is used as the trace gas. 
     
     
         2 . The method according to  claim 1 , characterised in that at least one additional trace gas is added to the propellant gas in addition to the hydrogen. 
     
     
         3 . The method according to  claim 1 , characterised in that said propellant gas is selected from the group consisting of nitrogen, nitrogen-rich gas mixtures, carbon dioxide, carbon dioxide-rich gas mixtures and saturated hydrocarbons. 
     
     
         4 . The method according to  claim 3 , characterised in that said saturated hydrocarbons are selected from the group consisting of methane. 
     
     
         5 . The method according to  claim 1 , characterised in that the proportion of the trace gas hydrogen in the propellant gas/trace gas mixture is a maximum of 10% by vol. 
     
     
         6 . The method according to  claim 1 , characterised in that the proportion of the trace gas hydrogen in the propellant gas/trace gas mixture is a maximum of 5% by vol. 
     
     
         7 . The method according to  claim 2 , characterised in that helium is used as a further trace gas. 
     
     
         8 . The method according to  claim 1 , characterised in that the propellant gas/trace gas mixture is blended immediately before it is introduced into the ground. 
     
     
         9 . The method according to  claim 1 , characterised in that the propellant gas/trace gas mixture is injected into the ground at a depth of at least one metre below the earth's surface.