Abstract
Pyrolysis/evaporation-gas chromatography was carried out on 11 samples from the Handi borehole, Mahakam delta, Indonesia, the samples being unextracted. The amounts of the product (pristane) and of the precursors (measured as pristenes) were determined simultaneously. The resulting Pristane Formation Index (PFI), (pristane)/((pristane) + (pristenes)), shows very high correlations with maturity parameters such as vitrinite reflectance, Carbon Preference Index and burial depth. A regression plot is presented of PFI on % vitrinite reflectance; the average experimental error of PFI is 5%. The values of PFI range 0.09-0.95, and = or >85% of the amount of pristane in the deepest sample may have originated from one type of precursor. The high correlations of PFI with other maturity parameters suggest that pristenes and pristane represent the precursor and product respectively of one reaction. The kinetic parameters E and A of the Arrhenius equation k = A exp (-E/RT) are calculated.