oa Oil to Oil Correlation Studies in Marun and Kupal Oilfields (SW of Iran) Using Gas Chromatography-Mass Spectrometry-Mass Spectrometry (GC/MS/MS)

Marun and Kupal oilfields situated in south east of Ahwaz city next to Agha Jari and Ahwaz oilfields are<br>among the largest oilfields in the Dezful Embayment. Sarvak Formation constitndes the main reservoir.<br>In order to investigate geochemical characteristics, the distribution of "molecular fossils" (biomarkers)<br>in extracts from some specific geologic age in the Marun nd kupal Basins have been analyzed and are<br>used as the fingerprints for the oil-oil and oil-source correlation. Obviously, not any molecular fossil<br>related to source and environment can be used as the fingerprints for oil-oil correlation. Some special<br>biomarkers widely existed in the extracts in the Sarvak reservoir and showed obvious similarity in both<br>reservoirs, including dinosteranes (m/z=414-98), desmethylsteranes (m/z=414-217), methylsteranes<br>(m/z=414-231), C24norcholestanes and c28 Steranes originated from dinoflagellates and diatom. The<br>amazing similarity of the relative contents of these compounds between the marine oils produced in<br>sarvak reservoir of Kupal and marun oilfields suggests that the Middle Triassic is the very likely main<br>source for the sarvak reservoir in understudied oilfields. Based on maturity and source rock lithology<br>parameters of biomarkers, the candidate source rock(s) are carbonates deposited in anoxic conditions<br>and are thermally mature.