Characterization of petroleum source rocks and shales by pyrolysis-gas chromatography-mass spectrometry-multiple ion detection

Abstract

A number of organic rich shales and potential source rocks from Australia and Alaska have been examined by pyrolysis-gaschromatography-mass spectrometry-multiple ion detection. Attempts have been made to observe variations in the distributions of biomarkers released from the samples by pyrolysis. Particular emphasis has been placed on the release of pentacyclic triterpanes to evaluate whether or not a one-step pyrolysis method can be used to determine relative maturity of the samples. Immature shales are observed to produce C 27 and C 29 hopenes, not present at higher levels of maturity, as well as number of hopanes and moretanes. Variations in the distributions of alkylbenzenes, alkanes, alkenes, sesquiterpenoids and diterpenoids can also be monitored during the pyrolysis reaction and provide information on the nature of the source material in the samples.