Discovery of the Helium Rare Gasin Saugor Division, Southern Ganga Basin,Bundelkhand Region, MP, India

摘要

The discovery of the helium rare gas in the wells in Saugor Division, southern Ganga Basin region has been done in Sagar District. The stable isotopic analyses were carried out for the gas samples collected from the 50 tube wells in Sagar and Damoh District of MP. The discovery of the rare gas helium in hydrocarbon rich zone in the tube wells in agricultural field at Garhakota, Rahatgarh, Bina, Banda and Sagar Tahsils, of District and Batiyagarh, Patharia, Jabera, tahsils in Damoh District of MP is aunique finding in rocks of the Vindhyan Super Group, in the history of Earth Science in India. The depth of tube wells varying from 300 to 750 ft. On the basis of geochemical analysis, it is remarkable to note that average values of helium contents varies from 0.34 to 0.732% along with the 72-99% of methane and ethane, and minor amount of oxygen, nitrogen, and CO_2 gases in the hydrocarbon rich zone are recorded during the geochemical and stable isotope analysis. It has been found in the stable isotopeS C~(13) value, the values for the methane is -43.6 to -54.9%o w.r.t. PDB. For the Ethane gas it is -24.9 to -26.4%0 w.r.t. PDB in the gas samples collected in the saturated sodium chloride solution in the glass bottles at various sites in Sagar and Damoh District. The occurrence of rare helium gas in the Hydrocarbon rich zone was reported for the first time in lanuary, 2007 from the tube wells of Sagar District, which were geochemically and isotopically stable, analysed in the labs of KDMIPE Dehradunand NGRI Hydrabad. The gaseous hydrocarbon analysis shows the presence of moderate to low concentration of methane (CI) 1 to 104 ppb, Ethane (C2) -1 to 14 ppb, Propane (C3) 1 to 10 ppb, i-Butane (i C4) 1 to 9 ppb, and n Butane (n C4) 1 to 8 ppb in the soil samples collected from different locations. The result of the adsorbed soil gas and stable isotopic analysis of Ethane gas in these samples have 5 C~(13_ value ranging from -24.9%o w.r.t. PDB and -26.9%o w.r.t. PDB, and these are indicative that the gas is of thermogenic origin, which must have been formed at very high temperature and pressure condition in the deeper horizon of the Great Vindhyan sedimentary basin of an early Proterozoic (>600 m.y.) period.