Sedimentary Environment, Diagenesis, and Reservoir Quality of Sarvak Formation (Upper Part) in Siri (E) Oilfields

Document Type : Research Paper

Authors

1 Department of Geology, Science and Research Branch, Islamic Azad University (IAU), Tehran

2 School of Geology, College of Science, University of Tehran

3 Research Institute of Petroleum Industry, Tehran

Abstract

The Sarvak formation (Late-Albian-middle Turonian) is one of the main oil and gas reservoir units in the southern and southwest of Iran after Asmari formation (Oligo-Miocene). It hosts an important amount of hydrocarbon reserves in this region. Detailed thin section studies of this formation in the Siri field led to the identification of 9 major microfacies, which are deposited in four facies belts (basin, outer-ramp, mid ramp, and inner ramp) in a homoclinal ramp-type platform. Main diagenetic processes affecTed carbonate of this formation are neomorphism, bioturbation, micritization, dolomitization, extensive dissolution, cementation, stylolitization, and fracturing. Diagenetic processes at the upper part of the Sarvak formation and the relative timing indicate that these processes occur in three main diagenetic environments, including marine, meteoric, and burial. The correlation between the porosity and permeability values of core data shows that the reservoir quality is affected by sedimentary environment, sedimentary facies, and subsequent diagenetic processes. Thus the rudists facies (grainstone, rudstone, and floatstone) have a maximum porosity and permeability
 

Keywords


[1]. مطیعی ه.، زمین‌شناسی ایران، چینه‌شناسی زاگرس، سازمان زمین‌شناسی کشور، 1372، ص 536.##
[2]. James G. A. and Wynd J. G., Stratigraphic nomenclature of Iranian oil consortium agreement area, American Association of Petroleum Geologist, Bulletin 49, pp. 2182-2245, 1965.##
[3]. Al- Husseini M. L., “Jurassic sequence stratigraphy of the Western and Southern Arabian Gulf: GeoArabia,” Vol. 2, No. 4, pp. 361- 382, 1997.##
[4]. Alsharhan A. S. and Nairn A. E. M., “A review of the Cretaceous formations in the Arabian Peninsula and Gulf: part I, Lower Cretaceous (Thamama Group), stratigraphy and paleogeography,” Journal of Petroleum Geology., Vol. 9, pp. 365-392, 1986.##
[5]. Van Buchem F., Letouzey J., Gaumet F., Rudkiewicz J. L., Mengus J. M., Baghbani D., Sherkati S., Asillian H., Keyvani F., Ashrafzade R., and Ehsani M. H., “The petroleum system of the Dezful embayment and Northern Fars (Southwest Iran),” NIOC Internal Report No. 55, pp.1- 729, 2001.##
[6]. Taghavi A. A., Mork A., and Emadi M. A., “Sequence stratigraphically controlled diagenesis governs reservoir quality in the carbonate Dehluran field,” SW Iran, Petroleum Geoscience 12, pp. 115-126, 2006.##
[7]. Hajikazemi E., Al-Aasm I. S., and Coniglio M., “Subaerial exposure and meteoric diagenesis of the Cenomanian- Turonian Upper Sarvak Formation, Southwestern Iran,” In. Leturmy, P. & Rabin, C. (eds), Thctonic and Stratigraphic Evolution of Zagros and Makran during the Mesozoic- Cenozoic, Geological Society, London, Special Publication.,Vol. 330, pp. 253-272, 2010.##
[8]. Rahimpour-Bonab H,. Mehrabi H., Enayati-Bidgoli A. H., and Omidvar M., “Coupled imprints of tropical climate and recurring emergence on reservoir evolution of a mid Cretaceous carbonate ramp,” Zagros Basin, Southwest Iran, Cretaceous Research., Vol. 37, pp.15-34, 2012.##
[9]. Setudehnia A., “The Mesozoic sequence in southwest Iran and adjacent areas,” Journal of Petroleum Geology Vol.1, pp. 3-42, 1978.##
[10]. Harris P. M., Frost S. H., Seiglie G. A., and Schneidermann N., “Regional unconformities and depositional cycles,” Cretaceous of the Arabian Peninsula In: Schlee, J. S. (Ed.), Interregional Unconformities and Hydrocarbon Accumulation, American Association of Petroleum Geologists, Memoir., Vol. 36. pp. 67-80, 1984.##
[11]. Dickson J. A. D., “A modified staining technique for carbonate in thin section,” Nature., Vol. 205, pp. 587, 1965.##
[12]. Dunhum R. J., “Classification of carbonate rocks according to depositional texture.,” In: Ham, W.E. (ed.), Classification of carbonate rocks. American Association of Petroleum Geologists, Memoir., Vol.1, pp.108-121, 1962.##
[13]. Embry A. F. and Klovan J. E., “A Late Devoninan reef tract on northeastern Banks Island Northwest Territories,” Bulletin of Canadian Petroleum Geology, Vol. 19, pp. 730- 781, 1971.##
[14]. Flugel E., “Microfacies of Carbonate Rocks: analysis, interpretation and application,” Springer, Berlin Heidelberg, New York., pp. 984, 2010.##
[15]. Wilsone J. L., “Carbonate Facies in Geologic History,” Springer Verlag. New York, pp.471, 1975.##
[16]. Ghabeishavi A., Vaziri- Moghadam H., Thaheri A and Taati F., “Microfacies and depositional environment of the Cenomanian of the Bangestan anticline,” SW Iran,” Journal of Asia Earth Science, Vol. 37, pp. 275-285, 2010##
[17]. Pomar L., “Types of carbonate ramp: a genetic approach,” Basin Research.,Vol.13,pp. 313-334, 2001.##
[18]. Aqrawi A. A. M., Thehni G. A., Sherwani G. H and Karem Mid- “Cretaceous rudist- bearing carbonates of the Mishrif formation: an important reservoir sequence in the Mesopotamian basin, Iraq,” Journal of Petroleum Geology, Vol. 21, pp. 57-82, 2007.##
[19]. Murris R. J., “Middle east: stratigraphic evolution and oil habitat,” American Association of Petroleum Geologists, Bulletin., Vol. 64, pp. 597-618, 1980.##
[20]. Beydoun Z. R., “Arabian plate hydrocarbon geology and potential-a plate tectonic approach,” American Association of Petroleum Geologists, Studies in Geology, pp. 33-77, 1991.##
[21]. Beydoun Z. R., Hughes Clarke M. W., and Stoneley R., “Petroleum in the Zagros Basin: a late Tertiary foreland basin overprinted onto the outer edge of a vast hydrocarbon-rich PaleozoiceMesozoic passive margin shelf,” In: Macqeen, R., Leckie, D. A. (Eds.), Foreland Basins and Fold Belts, American Association of  Petroleum Geologists., Memoir, Vol. 55, pp. 309-339, 1992.##
[22]. Fluteau F., Ramstein G., Besse J., Guiraud, R., and Masse J.P., “Impacts of palaeogeography and sea level changes on Mid-Cretaceous climate,” Palaeogeography, Palaeoclimatology, Palaeoecology, Vol. 247, pp. 357-381, 2007.##
[23]. Keller G., Adatte T., Berner Z., Chellai E. H., and Stueben D., “Oceanic events and biotic effects of the Cenomanian-Turonian anoxic event,” Tarfaya Basin, Morocco, Cretaceous Research., 29:, pp. 976-994, 2008.##
[24]. Hollis C., “Diagenetic controls on reservoir properties of carbonate successions within the Albian-Turonian of the Arabian Plate, Petroleum” Geoscince, Vol. 17, pp. 223-241, 2011.##
[25]. Bathurst R. G. C., “Carbonate sediment and their diagenesis. Developments in sedimentology,” Elsevier, Amsterdam, No. 12, 1975.##
[26]. Morrow D. W., “Diagenesis, dolomites, part two: dolomitization models and ancient dolostones,” Geoscience Canada., Vol. 9, pp. 95-107, 1982.##
[27]. Machel H. M., “Concepts and models of dolomitization: a critical reappraisal,” In: Braithwaite C. J. R., Rizzi G., Darke G. (Eds), The Geometry and petrogenesis of dolomite hydrocarbon reservoirs, Geological Society, London, Special Publication., Vol. 235, pp. 7-63, 2004.##
[28]. Kamali M. R., Lemon N. M., and Apark S. N., “Porosity generation and reservoir potential of Ouldburra Formation carbonates, Officer Basin, South Australia,” Australian Petroleum Exploration Association (APEA) Journal., Vol. 35, pp. 106-120, 1995.##
[29]. Tucker M. E. and Wright V. P., “Carbonate Sedimentology, Blackwell, Oxford,” pp. 482, 1990.##
[30]. Tucker M. E. and Bathurst R. G. C., “Carbonate diagenesis, Reprint Series,” AIS, Blackwell Scientific Publication. Vol. 1, AIS, Blackwell Scientific Publication.##