Geochemical Characteristics of Asmari, Sarvak and Khalij reservoirs in Pazanan and Khaviz Oil Fields Using Gas Chromatography and Gas Chromatography-Mass Spectrometry

Document Type : Research Paper

Authors

1 Department of Earth Sciences, Basic Science Faculty, Islamic Azad University, Science and Researches Branch, Tehran, Iran

2 Organic Geochemistry Department, Geology Institute, Research Institute of Petroleum Industry, (RIPI) Tehran, Iran

Abstract

In this study, two oil samples from Asmari and Sarvak reservoirs (well No#23) in Pazanan oil field and one oil sample from Khalij reservoir (well No#1) in Khaviz oil field were subjected to geochemical analyses using Gas Chromatography (GC) and Gas Chromatography Mass-Spectrometry (GC/MS) techniques. Quantitative assessment of the oil components using liquid chromatography method revealed that oil samples have a greater amount of saturated hydrocarbon component than the aromatic and polar. Classification of the crude oil samples based on different components shows that the Asmari and Sarvak reservoir oil in Pazanan oil field and Khalij reservoir oil in Khaviz oil field are paraffinic, mainly paraffinic to paraffinic - naphthenic and paraffinic – naphthenic respectively. The biomarker ratio obtained from C29 Sterane ββ∕(ββ+αα) versus C29 Sterane 20S/(20S+20R) diagram demonstrates that the oil samples were produced at the maximum stage of the oil producing window and have relatively high thermal maturity. The DBT/Phen versus Pr/Ph diagram shows that the Asmari oil samples have been produced from carbonate-shale, and Sarvak and Khlij oil samples have been produced from carbonate-marl source rocks. Also, triangular C27, C28, C29 sterane diagram indicates that the source rocks have been deposited in open marine to parallic environment. Also, oil has been generated from organic matter with type II kerogen as inferred from Pr/nC17 versus Ph/nC18 diagram. The proximity of the Carbon Preference Index (CPI) to the number 1, indicates high maturity level for source rocks. Absence of oleanane biomarker in oil samples suggests that oils be produced from lower-Cretaceous source rocks. Oil-oil correlation using distinctive biomarkers allowed to plot the stellar graph.  Finally, the even/odd ratio of normal alkanes determines that the oil samples from Asmari, Sarvak, and Khalij reservoirs have been produced from a variety source rocks.
 

Keywords


[1]. نظریان سامانی پ. و صنوبرلیماکشی ع.، "مقایسه ژئوشیمیایی نفت مخزن آسماری میادین نفتی پارسی، پازنان و رگ سفید در فروافتادگی دزفول جنوبی با استفاده از زیست نشانگرها"، مجله علوم زمین، شماره 59، سال پانزدهم. ##
[2]. عزیزی ع.، ارزیابی ژئوشیمیایی هیدروکربن‌های چشمه‌های نفتی و مخازن موجود در جنوب ناحیه ایذه، پایان‌نامه کارشناسی ارشد، دانشگاه شهید چمران اهواز، ایران، 1390. a
[3]. Tissot B. P. and Welte D. H., “Petroleum formation and occurrence”, 2nd ed. Springer-Verlag,New Yor, 1984. ##
[4]. Peters K. E. and Fowler M. G, “Application of Petroleum Geochemistry to Exploration and Reservoir Management,” Organic Geochemistry, Vol. 33, Issue 1, pp. 5-36, January 2002. ##
[5]. Peters K. E., Clifford C. E. and Moldwan J. M., “The biomarker guide”, 2nd ed., Prentice Hall, New Jersey, 2005. ##
[6]. Hunt J. M., “Petroleum geochemistry and geology”, 2nd ed., W. H .Freeman and Company, New York, 1996. ##
[7]. Hughes W. B., Holba A. G, L. I. P, “The ratios of dibenzothiophen to phenantherene and pristane to phytane as indicatore of depositional environment and lithology of petroleum source rocks”, Geochimical et Cosmochimica Acta., Vol. 59, pp. 3581-3598, 1995. ##
[8]. Connan J. and Cassou A. M., “Properties of gases and petroleum liguids derived from terrestrial kerogen at various maturation levels”, Geochemicl Consmochemical, Acta., Vol. 44, Issue 1, pp. 1-23, 1980. ##
[9]. Peters K. E.,Cluston M. J.,Robertson G., “Mixed marine and locustrine input to an oil-cemented sandstonee breccia from brora, scotland,” Organic Geochemistry, Vol. 12, pp. 61-73, 1999. ##
[10] قربانی ب. و کمالی م. ح .، کاربرد نشانه‌های زیستی درژئوشیمی آلی، انتشارات پژوهشگاه صنعت نفت ، 1390. ##
[11]. Kaufman R .L., Ahmed A. S. and Elsinger R. J., “Gas chromatography as a development and production tool for fingerprinting oils from individual reservoirs: application in the Gulf of Mexico,” In GCSSEPM foundation ninth annual research conference proceedings, Vol. 9, 263- 282, 1990. ##