Investigation on the Geochemical Properties of Potential Source Rocks in South Pars Field

Document Type : مقالات پژوهشی

Authors

• Roshanak Sonei ¹
• Hossain Rahimpour-Bonab ¹
• Mahmud Memariyani ²
• Ashkan Asadi-Eskandar ¹

¹ Departement of Geology, College of Science, University of Tehran, Iran

² Research Institute of Petroleum Industry (RIPI), Tehran, Iran

10.22067/sed.facies.v1i1.667

Abstract

Based on enormous gas reserves and good potential for production from oil-bearing layers (Upper Dariyan, Lower Dariyan and Sarvak Formations), South Pars Field is one of the most important hydrocarbon reserves in the Iran. The goal of this study is to determine the geochemical properties, such as quantity, quality and thermal maturity of the organic matters, of possible source rocks that might have a role in generation of hydrocarbon in the past. Therefore, core and cutting samples of the Surmeh, Fahliyan and Gadvan Formations from three exploratory oil wells in the South Pars Field, namely A, B and C, were analyzed using Rock-Eval pyrolysis and burial history reconstruction. The results of Rock-Eval pyrolysis show that such beds are not good sources and have poor to fair content of organic matter in which the total organic carbon richness (TOC) ranged between 0.1 and 0.64 Wt%. These three formations generally contain kerogen type II and III. Most of the studied samples are mainly gas-oil-prone organic matter (OM) with hydrogen index (HI) ranged between 150 and 300, associated with gas prone (OM) of (HI) 300. The maturity of these source beds ranges from immature to early mature-oil window in these three wells, as inferred from the production index (PI), Tmax. Thus, no potential gas/oil source intervals were encountered in three wells. Burial history reconstruction indicates that at the end of the Cretaceous time, Permian to Cretaceous sediments remained immature in the Qatar Arch. Therefore, Surmeh, Fahliyan and Gadvan Formations could not be the source rock of the oils in this field.

Keywords

• Possible source rock
• thermal maturity
• Rock-Eval Pyrolysis
• hydrogen index
• oil window
• burial history

---

References

آلی، ج.، 1385. ژئوشیمی مخازن گازی دهرم در میدان پارس جنوبی با نگرش خاص بر منشأ H2S. رساله دکتری در گرایش رسوب شناسی و سنگ شناسی رسوبی، دانشکده علوم زمین، دانشگاه تهران. 234 ص.

Aali, J., Rahimpour-Bonab, H. & Kamali, M.R., 2006. Geochemistry and origin of the world's largest gas field from Persian Gulf, Iran. Journal of Petroleum Science and Engineering, 50:161-175.

Barker, C., 1974. Pyrolysis techniques for source-rock evaluation. AAPG Bulletin, 58:2349-2361.

Bordenave, M.L., 1993. Applied Petroleum Geochemistry. Editions Technique, Paris, 524p.

Espitalie, J., Madec, M., Tisssot, B., Menning, J.J., & Leplate, P., 1977. Source rock characterization method for petroleum exploration. Proceeding of the 9th Annual Offshore Technology Conference, 3:439-448.

Hunt, J.M., 1996. Petroleum Geochemistry and Geology. 2nd edition. W.H. Freeman and Company, New York, 743p.

Kennard, J.M., Deighton, I., Edwards, D.S., Boreham, C.J. & Barrett, A.G., 2002. Subsidence and thermal history modelling: new insights into hydrocarbon expulsion from multiple petroleum systems in the Petrel Sub-basin, Bonaparte Basin. In: Keep, M., & Moss, S., (eds.), The Sedimentary Basins of Western Australia 3, Proceedings of the Petroleum Exploration Society of Australia Symposium, Perth, 2002, 409–437.

Konert, G., Afifi, A.M., AL-Hajri, S.A., & Droste, H.J., 2001. Paleozoic stratigraphy and hydrocarbon habitat of the Arabian Plate. GeoArabia, 6:407-442.

Milner, P., 1998. Source rock distribution and thermal maturity in the Southern Arabian Peninsula. GeoArabia, 3:339-356.

Murris, R.J., 1980. Middle East: Stratigraphy evolution and oil habit. AAPG Bulletin, 64:592-618.

Page, M.M., & Kuhnel, C., 1980. Rock-Eval Pyrolysis as source rock screening technique. AAPG Bulletin, 64:762.

Peters, K.E., 1986. Guidelines for evaluating petroleum source rock using programmed pyrolysis. AAPG Bulletin, 70:318-329.

Waples, D.W., 1985. Geochemistry in petroleum exploration. D. Redial Publishing Company, 232p.

Ziegler, M.A., 2001. Late Permian to Holocene Paleofacies of the Arabian Plate and its Hydrocarbon Occurrences. GeoArabia, 6:445-504.