EXPERIMENTAL HEATING AND KINETIC-MODELS OF SOURCE ROCKS - COMPARISON OF DIFFERENT METHODS

Closed system isothermal micro pyrolysis has been carried out for nine Upper Jurassic source rocks from the Norwegian Shelf, supplemented by hydrous pyrolysis experiments and open-system Pyromat kinetic determi nations. In all investigated cases open-system kinetics is able to mod el the residual potential derived from S2 but not the respective low-t emperature, closed-system isothermal experiments. The relatively detai led micro pyrolysis generation patterns obtained, allow us to differen tiate between primary generation and secondary cracking of different c arbon number classes of hydrocarbons. Formation of non-hydrocarbons or hydrocarbon ''sinks'' in residues can be inferred from these patterns . Comparison of results from low- and high-temperature experiments sug gests that the ''potential'' of a source rock may vary according to he ating history. Discrepancies between high- and low-temperature experim ents may be explained in terms of competing reaction pathways. These m ay constitute a main source of uncertainty when extrapolating bulk kin etics models into geological conditions.