عنوان مقاله [English]
Investigating of dolomitization and its effects on reservoir quality of the Upper Dalan Formation with Permian-Triassic in age is the aim of this study. In this section, the Upper Dalan Formation consists of carbonates and evaporite rocks with a thickness of 265m. Eleven carbonate- evaporate microfacies have been distinguished on the basis of depositional textures, petrographic analysis and present fauna. These microfacies were deposited in three facies belts including tidal flat, lagoon and carbonate shoal. Absents of turbidite (calciturbidite) and tempesties deposits, slump structures, large barrier reef, widespread tidal flat and lagoonal facies with aboundent of mud matrix indicated that depositional setting of this interval was a homoclinal carbonate ramp. Based on petrographic studies, 4 types of dolomite including dolomicrite, dolomicrosparite, dolosparite and dolomite cement are recognized. Porosity and permeability data in varies dolomites reveals that in most dolomite the amount of permeability is not directly related to whole porosity, but depends mainly on the amount of connected porosities through bottleneck holes and is associated with increasing in dolomite crystal sizes. Therefore, from the early stage of dolomitization in the form of dolomicrite toward increasing in the rate of dolomitization with larger crystal size and with the form of subhedral and euhedral crystals, the reservoir properties had a high visible improvement. Ultimately, by persisting of dolomitization and growth of dolomite crystals toward each other and disappearance of bottleneck holes and creation of dolomite cements, reservoir properties destroyed. Dolomitization increased reservoir quality in grain dominated dolo-packstones with planner crystal texture.
Aali, J., Rahimpour-Bonab, H. and Kamali, M. R., 2006- Geochemistry and origin of natural gas in the world’s largest non-associated gas field. Journal of Petroleum Science and Engineering, v. 50, p. 163–175.
Adabi, M. H., 2009- Multistage dolomitization of the Upper Jurassic Mozduran Formation, Kopeh dagh Basin, NE Iran, Carbonates and Evaporites, v. 24, p. 16-32.
Adabi, M. H., Kakemem, U. and Sadeghi, A., 2016- Sedimentary facies, depositional environment, and sequence stratigraphy of Oligocene–Miocene shallow water carbonate from the Rig Mountain, Zagros basin (SW Iran). Carbonates and evaporites, v. 31(1), p. 69-85.
Ahr, W. M., 2008- Geology of Carbonate Reservoirs. John Wiley and Sons, 296 pp.
Burchette, T. P. and Wright, V. P., 1992- Carbonate ramp depositional systems. Sedimentary Geology, v. 79, p. 3-57.
Buxton, M. W. N. and Pedley, H. M., 1989- A standardized model for Tethyan Tertiary carbonate ramps. Journal of the Geological Society, v. 146, p. 746-748.
Dickson, J., 1965- Carbonate identification and genesis as revealed by staining, Journal of Sedimentary Petrology, V. 205, p. 491-505.
Dunham, R. J., 1962- Classification of carbonate rocks according to depositional textures. Journal of American Assocition Petroleum Geology, 108-121.
Feldman, M. and Mckenzie, J., 1998- Stromatolite-Thrombolite associations in a modern environment, Lee Stocking Island, Bahamas. Palaios, v. 13, p. 201-212.
Flügel, E., 2010- Microfacies analysis of limestone, analysis interpretation and application, Berlin: Springer-Verlag.
Geel, T., 2000- Recognition of stratigraphic sequences in carbonate platform and slope deposits: empirical models based on microfacies analysis of paleogene deposits in southeastern Spain, Palaeogeography, Palaeoclimatology, Palaeoecology, v. 155, p. 211–238.
Gregg, J. M. and Sibley, D. F., 1984- Epigenetic dolomitization and the origin of xenotopic dolomite texture Journal of Sedimentary Petrology, v. 54, p. 908-931.
Hips, K. and Hass, J., 2006- Calcimicrobial stromatolites at the PermianTriassic boundary in a western Tethyan section, Bukk Mountains, Hungary: Sedimentary Geology, v. 185, p. 239- 253.
Insalaco, E., Virgone, A., Courme, B., Gaillot, J., Kamali, M., Moallemi, A., Lotfpour, M. and Monibi, S., 2006- Upper Dalan Member and Kangan Formation between the Zagros Mountains and offshore Fars, Iran: Depositional system, biostratigrarhy and stratigraehic architecture: Geo Arabia, v. 11, p.75-176.
James, N. P., and Jones, B., 2016- Origin of Carbonate Sedimentary Rocks. Wiley, London, pp. 446.
Kakemem, U., Adabi, M. H., Sadeghi, A. and Kazemzadeh, M. H., 2016- Biostratigraphy, paleoecology, and paleoenvironmental reconstruction of the Asmari formation in Zagros basin, southwest Iran. Arabian Journal of Geosciences, v. 9(2), p.1-15.
Lucia, F. J. and Conti, R. D., 1987- Rock fabric, permeability, and log relationships in an upward-shoaling, vuggy carbonate sequence, The University of Texas at Austin, Bureau of Economic Geology Geological Circular 87-5, p. 22.
Lucia, F. J., 1995- Rock-fabric/petrophysical classification of carbonate pore space for reservoir characterization. American Association of Petroleum Geologists, 79(9), pp.1275-1300.
Lucia, F. J., 2007- Carbonate Reservoir Characterization: An Integrated Approach Springer, Second Edition, 366 pp.
Martini, R., Cirilli, S., Saurer, C., Abate, B., Ferruzza, G. and Cicero, G. L., 2007- Depositional environment and biofacies characterisation of the Triassic (Carnian to Rhaetian) carbonate succession of Punta Bassano (Marettimo Island, Sicily). Facies, v. 53(3), p.389-400.
Mazzullo, L., 1992- Geochemical and neomorphic alteration of dolomite: a review, Carbonates and Evaporites, v. 7, p. 21- 37.
Mountjoy, E. W. and Marquez, X. M., 1997- Predicting reservoir properties in dolomites: Upper Devonian Leduc buildups, Deep Alberta Basin. In: Kupecz, J.A., Gluyas, J., Bloch, S. (Eds.), Reservoir Quality Prediction in Sandstones and Carbonates: American Association of Petroleum Geologists Memoir, 69, p. 267-306.
Pomar, L., 2001- Types of carbonate platforms: a genetic approach. Basin Research, v. 13, p. 313–334.
Read, J., 1985- Carbonate platform facies models. American Association of Petroleum Geologists, v. 69, p. 1-21.
Sibley, D. F. and Gregg, J. M., 1987- Classification of dolomite rock texture, Journal of Sedimentary Petrology, v. 57, p. 967-975.
Tucker, M. E. and Wright, V. P., 1990- Carbonat Sedimentology, Blackwell Scientific Publications, Oxford, pp. 482.
Warren, J. K., 2000- Dolomite: occurrence, evolution and economically important associations. Earth Science Reviews, v. 52, p. 1-81.
Wilson M. E. J. and Evans M. E. J., 2002- Sedimentology and diagenesis of tertiary carbonates on the Mangkalihat Peninsula, Borneo: implications for subsurface reservoir quality. Marine and Petroleum Geology, v. 19, p. 873–900.
Wilson, J. L., 1975- Carbonate Facies in Geologic History, Springer Verlag, New York, pp. 471.