COMPARISON OF KINETIC-ANALYSIS OF SOURCE ROCKS AND KEROGEN CONCENTRATES

Shales and kerogen concentrates from the Green River, Rundel, Ohio, Dr aupne, and Phosphoria formations were examined by Pyromat II micropyro lysis and kinetic parameters were determined by the shift-in-T(max), d iscrete distribution, modified Friedman, and modified Coats-Redfern me thods. Overall, the shales and corresponding kerogens exhibited very s imilar kinetic parameters. Green River, Rundel, and Ohio shales and ke rogens exhibited principal discrete activation energies of 54-57 kcal/ mol, narrow distributions, and T(max) at 25-degrees-C/min heating rate around 480-degrees-C. Draupne and Phosphoria shales and kerogens exhi bited kinetic parameters typical of Type II source rocks-principal dis crete activation energies of 54-57 kcal/mol, broad distributions, and T(max) at 25-degrees-C/min around 459-degrees-C. The discrete distribu tion kinetic parameters were used to calculate oil generation at labor atory and geological heating rates. Each shale and corresponding kerog en exhibited generation curves and 50% generation temperatures that we re very similar. The principal difference was that the kerogens exhibi ted slightly more oil generation at low temperatures compared to the c orresponding shales. Some kerogens exhibited curves which were also sh ifted to slightly lower temperatures than those of the corresponding s hales. For these specific shales and kerogens, the results indicate th at kerogen isolation does little to affect the pyrolysis kinetic param eters. Although from a limited number of samples, these results sugges t kerogen isolation may not be necessary to derive valid kinetic param eters.