Origin of crude oils from oilfields in the Zagros Fold Belt,southern Iraq: Relation to organic matter input and paleoenvironmental conditions |
| |
| Institution: | 1. Geology Department, Faculty of Applied Science, Taiz University, 6803 Taiz, Yemen;2. College of Geophysics and Remote Sensing, Al-Karkh University, Iraq;1. A.P. Karpinsky Russian Geological Research Institute (VSEGEI), Sredny Av. 74, 199106, St. Petersburg, Russia;2. Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, 30655, Hannover, Germany;3. Institute of Geology, Leibniz University Hannover, Callinstraße, 30, 30167, Hannover, Germany;4. TOTAL EXPLO EAC /PN, 2 Place Jean Millier, 92069, Paris La Defense, France;1. Department of Geology, Faculty of Earth Sciences, Kharazmi University, Tehran, Iran;2. School of Earth Sciences, Shahid Beheshti University, Evin, Tehran, Iran;3. Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen AB24 3UE, United Kingdom;4. Faculty of Sciences, Shahid Chamran University, Ahwaz, Iran;1. Shahid Chamran University of Ahvaz, Faculty of Earth Sciences, Department of Petroleum Geology and Sedimentary Basins, Ahvaz, Iran;2. Petroleum Geology and Geochemistry Research Center (PGGRC), Ahvaz, Iran;3. Pars Petro Zagros Engineering & Services Co. (PPZ), Tehran, Iran;1. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Fuxue Road 18, Changping District, Beijing 102249, PR China;2. Research Institute of Petroleum Exploration and Development(RIPED), Petrochina, Beijing 100083, PR China;3. Research Institute of Experiment and Testing, PetroChina Xinjiang Oilfield Company, Karamay, 843000 Xinjiang Province, PR China |
| |
| Abstract: | Crude oil samples from Cretaceous and Tertiary reservoir sections in the Zagros Fold Belt oil fields, southern Iraq were investigated using non-biomarker and biomarker parameters. The results of this study have been used to assess source of organic matter, and the genetic link between oils and their potential source rocks in the basin. The oils are characterized by high sulphur and trace metal (Ni, V) contents and relatively low API gravity values (17.4–22.7° API). This indicates that these oils are heavy and generated from a marine source rock containing Type II-S kerogen. This is supported by their biomarker distributions of normal alkanes, regular isoprenoids, terpanes and steranes and the bulk carbon isotope compositions of their saturated and aromatic hydrocarbons. The oils are characterized by low Pr/Ph ratios (<1), high values of the C35 homohopane index and C31-22R/C30 hopane ratios, relatively high C27 sterane concentrations, and the predominance of C29-norhopane. These biomarkers suggest that the oils were generated predominantly from a marine carbonate source rock, deposited under reducing conditions and containing plankton/algal and microorganisms source input. The presence of gammacerane also suggests water column stratification during source rock deposition.The biomarker characteristics of the oils are consistent with those of the Middle Jurassic Sargelu carbonate as the effective source rock in the basin. Biomarker maturity data indicate that the oils were generated from early maturity source rocks. |
| |
| Keywords: | Crude oil Biomarker Depositional environment Source input Type II-S kerogen Sargelu Formation Zagros Fold Belt Southern Iraq |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
