Experimental controls on D/H and 13C/12C ratios of kerogen, bitumen and oil during hydrous pyrolysis

Arndt Schimmelmann , Jean-Paul Boudou (1) , Michael D. Lewan , Robert P. Wintsch

1 Bioemco - Biogéochimie et écologie des milieux continentaux

Large isotopic transfers between water-derived hydrogen and organic hydrogen occurred during hydrous pyrolysis experiments of immature source rocks, in spite of only small changes in organic 13C/12C. Experiments at 330'C over 72 h using chips or powder containing kerogen types I and III identify the rock/water ratio as a main factor affecting ASD for water and organic hydrogen. Our data suggest that larger rock permeability and smaller rock grain size increase the H-isotopic transfer between water-derived hydrogen and thermally maturing organic matter. Increasing hydrostatic pressure may have a similar effect, but the evidence remains inconclusive

Mots clés: Hydrous pyrolysis; Hydrogen isotopes; Carbon isotopes; Deuterium; Kerogen; Bitumen; Oil; Lignite; Isotope exchange; Maturation

Domaines: Géochimie

Arndt Schimmelmann, Jean-Paul Boudou, Michael D. Lewan, Robert P. Wintsch. Experimental controls on D/H and 13C/12C ratios of kerogen, bitumen and oil during hydrous pyrolysis. Organic Geochemistry, 2003, 32, pp.1009-1018. ⟨10.1016/S0146-6380(01)00059-6⟩. ⟨bioemco-00156849⟩