Hydrocarbon Source Rock Evaluation by Using the Rock-Eval: Evaluation of the Garu and Gadvan Formations in the High Zagros Area in the North of Dezful Embayment

Rock-Eval pyrolysis and oxidation are the most widely used methods by exploration companies for identifying and evaluating potential source rocks in sedimentary basins.
In this article, these methods and the parameters resulted from their application are first  explained.  Then,  based on screened data resulted from analyzing 499 outcrop samples by using Rock-Eval pyrolysis and oxidation methods, the hydrocarbon  source potentiality of Garau and Gadvan Formations in the high Zagros area in the North Dezful Embayment is discussed and presented as charts.The resulted parameters show that the Garau Formation in the Ghalikuh, Chamsangar and Galeh Tak Sections is a good to excellent source rock. The Hydrogen Index of the samples indicate that Garau Formation is capable of generating primarily oil and less gas in the Ghalikouh Section, oil and Gas in the Ghaleh Tak Section and primarily gas in the Chamsangar Section. “Tmax” values obtained for the samples from the three aforesaid sections indicate organic matter maturity levels in the range of oil generating zone.
Only a 30 meter interval of the 170 meter thick Kuh-e-Fahliyan geologic section from the Gadvan Formation is indicative of a good hydrocarbon source rock.