Kerogen degradation

Petsch S. T., Smernik R. J., Eglinton T. I., and Oades J. M. (2001) A solid state C-NMR study of kerogen degradation during black shale weathering. Geochim. Cosmochim. Acta 65, 1867-1882. 

One main application of basin modelling has been the assessment of timing and extent of petroleum generation in sedimentary basins using chemical kinetics of kerogen degradation determined experimentally on immature source rock samples (Vandenbroucke et al. 1999). However, in view of the kinetic variability observed in source rocks (Jarvie 1991 Sundaraman 1995) it is questionable whether such predictions are valid. 

In very few cases, for research purposes, certain chemical methods such as oxidation, hydrogenation, or application of some other reagents which could attack the sensitive sites of a kerogen subunit have been applied. However, research workers in this field are inclined to attack the kerogenic material by thermal degradation because retorting is the only common practice. 

Yamamoto, S., Yoshioka, H., and Ishiwatari, R. (2007). Pyrolysis- and chemical degradation-GC/MS analyses of environmental kerogen and humic substances and their applications to geochemistry. Bunseki Kagaku 56(2), 71-91. 

Electromagnetic radiation in the microwave frequency spectrum is absorbed most strongly by molecules with permanent dipole moments (4). The relaxation phenomenon of this absorbed power manifests itself in a heatlike reaction. The University of Colorado Oil Shale Project has studied the degradation of the liquid-fuel precursor (kerogen) by micro-wave interaction. Kerogen is a moderately strong absorber of this radia-... 

Decomposition of kerogen Decomposition of carbonate minerals Reaction of carbon with C02 Reaction of carbon with 02 Thermal degradation of oil Release of fixed water... 

The thermal properties of Devonian shale are quite different from those of Green River oil shale. The associated pyrite in kerogen concentrate may contribute greatly to the effect on thermal degradation of Devonian gas-bearing shale. For the first time DSC was applied to determining thermal properties of Devonian shale as well as Green River oil shale. 

Reservoirs of natural gas generally contain only small amounts of H2S, but in some cases contain 2-30% by volume H2S(g) (Hitchon et al., 2001 Worden and Smalley, 2001). Sources of this H2S include (i) degradation of sulfur-rich kerogen, (ii) breakdown of sulfur-rich crude oil, (iii) BSR, and (iv) TSR (Worden and Smalley, 2001 Machel, 2001). Bacterial sulfate reduction is generally limited to temperatures below — 80 °C,... 

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