The present invention relates to a gelatin soft capsule having the properties of removal of oral smell and cleaning of oral cavity, which contains the ingredient for masking an oral smell as an active ingredient. The well’s originating gas separates in a skid of separation of oil and after gas is rectified, gas is injected again into the well; the gas injection is made to a pressure enough to lift the oil-gas mixture inside the well. For example, reference sensors may be temporarily applied to monitor gas temperature and pressure, as well as the motion of a flow-responsive element in the gas meter.