GEOCHEMICAL SIGNIFICANCE OF HYDROCARBONS DESORBED FROM ASPHALTENES

Saturate hydrocarbon fractions desorbed (cleaned) from asphaltenes ext racted and separated from two core samples (a tar sand and a reservoir sandstone sample) were analyzed by gas chromatography-mass spectromet ry (GC-MS). The results indicated that n-alkanes adsorbed in asphalten es were kept quite well during and after severe biodegradation over 36 0 Ma. Hydrocarbon desorption could be an alternative method of, or eve n better than the pyrolysis of asphaltenes to reconstruct the hydrocar bon fingerprints of primary oils and extend the understanding of the o rigins of hydrocarbon reservoirs.