2nd International Congress on Recent Innovations in Engineering, Science and Technology - Istanbul - Turkey (2021-07-09)

SHALLOW SURFACE GEOCHEMICAL ASSESSMENT OF SUBSOIL METHANE DEPOSITS AND ITS IMPLICATIONS

Organic rich soils (peat) store significant amounts of global soil carbon in the form of methane (CH4) and carbon dioxide (CO2). Understanding both physical and biological processes of natural gas generation in peat is essential to find a better insight into the origin of shallow natural gas reservoirs in the South-West coast of Indian peatlands. This work discloses the composition and source of hydrocarbon escaping through the boreholes or weaker zones from shallow peat overlain by carbonaceous clay by using the methods of GC-MS and stable isotope analysis (δ13CCH4 and δDCH4). The natural gas compositions are characterized in this study by considering a three-component mixture of 92 mol% CH4, 0.5 mol% N2 and 7.4 mol% CO2 with varying temperature ranges and pressure of 101.3KPa. Our research hypothesis highlights the emanating natural gas being mainly derived through bacterial methanogenesis from organic matter rich peat by CO2 reduction pathway without mixing with thermogenic or landfill gases.
Keywords: Biogenic methane; Gas chromatography-mass spectrometry (GC-MS); Isotope; SW Indian peatlands
Shashank Sharma, Devi K, Rajesh Nair