Correlating palynofacies and hydrocarbon generation potential of the Kazhdumi Formation in Tange-Maghar


The kazhdumi Formation of the Bangestan Group is a well-know and important source rock in most oil-fields in the Zagros Basin. For the present study 52 rock samples from an outcrop in Tange-Maghar were collected and treated palynologically. Three palynofacies were differentiated and the results were compared with those gained from geochemical analysis. Palynofacies I (PF-1) with 90 to 100% Amorphous Organic Matter (AOM), high amounts of HI and TOC contains kerogent type II and could potentially produce oil. The second palynofacies (PF-2) contains reduced amounts of AOM, HI and TOC and the kerogen is of type II/III potentially producing oil and gas. Palynofacies type III contains a few samples characterized with low amounts of AOM, HI and TOC potentially producing meager amount of gas and oil. The high amounts of clear AOM in most samples indicates dominance of redox environmental condition with low oxygen content. The HI/OI ratios curve gained from the Rock Eval Pyrolysis indicates B and C areas which confirms this environmental condition. Plotting palynological data on Tyson ternary diagrams and Van kere volen geochemical diagrams indicate that the kerogen is of type II/II, III and is resulted in mainly from organic and algal matters. The potential for hydrocarbon generation is high for the samples with high amount of kerogent type II (palynofacies I) while is is relatively good for samples with high amounts of kerogent type II,III (palynofacies type II). Tmax indicates that the samples are mainly of mature or entering the mature phase and potentially able to produce oil and gas.