Application of Miniature Gas Mass Spectrometer in On-line Analysis of Gases in Onsite Chinese Continental Scientific Drilling Mud

H2, He, O2, N2, Ar, CH4 and CO2 in the Chinese Continental Scientific Drilling (CCSD) mud samples were on line analyzed by OmniStar gas mass spectrometer. The sampling equipment was properly designed and applied to the collection of the gases from the drilling hole to avoid the air pollution and remove the moisture in the drilling gases. The reliable analysis method was established with precision of less than 2%RSD (n=30) and high accuracy. And a great deal of credible data has been acquired for the scientific research in CCSD.