Document Type : Original Research Paper


1 Assistant Professor, Department of Geology, College of Basic Science, Science and Research Branch, Islamic Azad University (IAU), Tehran, Iran

2 Professor, Department of Geology, College of Science, University of Tehran, Tehran, Iran

3 Professor, Department of Geology, College of Science, Ferdowsi University of Mashhad, Mashhad, Iran

4 Assistant Professor, Department of Geology, North Tehran Branch, Islamic Azad University (IAU), Tehran, Iran

5 Master, Pars Oil and Gas Company (POGC), Tehran, Iran


The Early Triassic carbonates of Kangan Formation are major gas reservoirs in the Southwest of Iran and the northern Persian Gulf. Facies analyses of Kangan Formation led to recognition of 13 microfacies which are related to tidal flat, lagoon, shoal and open marine environments. Examination of vertical and lateral facies changes and thire comparison with their modern and ancient counterparts, all indicate that Kangan Formation were deposited in a shallow carbonate ramp platform similar to the present day Persian Gulf. The sequence stratigraphic studies showed that the Kangan Formation consists of two third order depositional sequences (in the A and B wells), each consisting of transgressive and highstand systems tracts. The lower boundary of the first sequence is a type 1 unconformity, but other boundaries are type 2 unconformity. Typical reservoir zone in the Kangan Formation is dominated in early highstand systems tract deposits and concentrated in shoal grainstone facies. However, in this paper, typical intervals such as sequence boundaries, maximum flooding surfaces, stacking patterns and system tracts were studied.  


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.

Al-Aswad, A. A., 1997- Stratigraphy, sedimentary environment and depositional evolution of the Khuff Formation in the south-central Saudi Arabia.: Journal of Petroleum Geology., v .20, 3, p.307-326.
Alavi, M., 2004- Regional stratigraphy of the Zagros fold-thrust belt of Iran and its proforeland evolution. American Journal of Science. 304. p. 1–20.
Al-Jallal, I. A., 1995-The Khuff Formation: Its regional reservoir potential in Saudi Arabia and other Gulf countries, depositional and stratigraphic approach, in M. I. Al-Huseini, ed., Geo’94, Middle East Petroleum Geosciences: Bahrain, Gulf PetroLink, 1,  p. 103– 119.
Al-sharhan, A. S. & Kendall, C. G. St. C., 2003- Holocene coastal carbonates and evaporites of the southern Arabian Gulf and their ancient analogues. Earth-Science Reviews. V, 61, p. 191–243.
Al-sharhan, A. S. & Naim, A. E. M., 1997- Sedimentary Basins and Petroleum Geology of the Middle East. Elsevier, Netherlands. p. 843.
Alsharhan, A. S., 1993- Facies and sedimentary environment of the Permian carbonates (Khuff Formation) in the United Arab Emirates: Sedimentary Geology. 84, p. 89–99.
Alsharhan, A.­ S., 2006- Sedimentological character and hydrocarbon parameters of the middle Permian to Early Triassic Khuff Formation, United Arab Emirates. GeoArabia. 11, p.121–158.
Baud, A., Richoz, S. & Pruss, S., 2007- The Lower Triassic anachronistic carbonate facies in space andtime. Global and Planetary Change, v. 55, nos. 1-3, p. 81-89.
Burchette, T. P. & Wright, V. P., 1992- Carbonate ramp depositional systems. Sedimentary Geology. 79, p3–57.
Calvet, F. & Tucker, M. E., 1988- Outer ramp carbonate cycles in the Upper Muschelkalk, Catalan Basin, N.E. Spain. Sediment. Geol., 57: 185-198.
Catuneanu, O., 2002- Sequence stratigraphy of clastic systems: concepts, merits, and pitfalls. Journal of African Earth Sciences 35: 1-43.
Catuneanu, O., 2006- Principles of Sequence Stratigraphy, (First Edition) Elsevier, Amsterdam. 375 pp.
Dunham, R. J., 1962- Classification of carbonate rocks according to depositional texture, in E. D. Ham, ed., Classification of carbonate rocks— Asymposium: AAPGMemoir. v. 1, p. 108–121.
Ehrenberg, S. N., 2006- Porosity destruction in carbonate platforms: Journal of Petroleum Geology, v. 29, p. 41–52.
Ehrenberg, S. N., Nadeau, P. H. & Aqrawi, A. A. M., 2007- A comparison of Khuff and Arab reservoir potential throughout the Middle East. AAPG Bulletin, v. 86, no. 10, p. 1709–1732
El gadi, M. S. M. & Brookfield, M. E., 1999- Open carbonate ramp facies, microfacies and paleoenvironments of the Gramame Formation (Maastrichtian), Pernambuco-ParaíbaBasin, Northeastern Brazil. Journal of South American Earth Sciences. 12,p. 411-433.
Esrafili-Dizaji, B. & Rahimpour-Bonab, H., 2009- Effects of depositional and diagenetic characteristics on carbonate reservoir quality: a case study from the South Pars gas field in the Persian Gulf. Petroleum Geoscience 15: p.325–344.
Fluagel, E., 2010- Microfacies Analysis Of  Carbonate Rocks, Analyses, Interpretation and Application, Springer verlag, p.976.
Fontana, S., Nader, F. H., Morad, S., Ceriani, A. & Al-Aasm, I. S., 2010- Diagenesis of the Khuff Formation (Permian–Triassic), Northern United Arab Emirates. Arab Journal Geoscience. p. 95-111.
Insalaco, E., Virgone, A., Courme, B., Gaillot, J., Kamali, M., Moallemi, A., Lotfpour, M. & Monibi, S., 2006- Upper Dalan Member and Kangan Formation between the Zagros Mountains and offshore Fars, Iran: Depositional system, biostratigraphy and stratigraphic architecture: GeoArabia. v. 11, p.75– 176.
Kashfi, M. S., 2000- Greater Persian Gulf Permian–Triassic stratigraphic nomenclature requires study. Oil and Gas Journal, Tulsa, Nov. 6, p. 36, 38, 40, 42, and 44.
Kershaw, S., Li, Y., Crasquin-Soleau, S., Feng, Q., Mou, X., Collin, P. Y., Reynolds, A. & Guo, L., 2007- Earliest Triassic microbialites in the South China block and other areas: Controls on their growth and distribution. Facies, v. 53, p. 409-425.
Khalifa, M. A., 2005- Lithofacies, diagenesis and cyclicity of the ‘Lower Member’ of the Khuff Formation (Late Permian), Al Qasim Province, Saudi Arabia, Journal of Asian Earth Sciences v.25 (2005), p.719–734
Koehrer,B.,  Heymann,C.,  Prousa,F. &Aigner,T., 2010- Multiple-scale facies and reservoir quality variations within a dolomite body – Outcrop analog study from the Middle Triassic, SW German Basin. Marine and Petroleum Geology, v. 27, Issue 2, p. 386-411.
Konert, G., Afifi, A. M., Al-Hajri, S. A., de Groot, K. M., Al Naim, A. A. & Droste, H. J., 2001- Paleozoic stratigraphy and hydrocarbon                habitat of the Arabian Plate: AAPG Memoir74, p. 483-515.    
Konyuhov, A. I. & Maleki, B., 2006- The Persian Gulf Basin: Geological history, sedimentary formations, and petroleum potential. Lithology and Mineral Resources, Vol. 41, No. 4.
Lee, Y. I., Hyeong, K., Yoo, S. & Yoo, C. M., 2001- Cyclic sedimentation across a middle Ordovician carbonate ramp (Duwibong Formation), Korea. Facies. v. 44, p. 61-74.
Lucia, F. J., 2007- Carbonate Reservoir Characterization An Integrated Approach, Springer-VerlagBerlinHeidelberg. Second Edition., p.366.
Maurer, F., Martini, R., Rettori, R., Hillgärtner, H. & Cirilli. S., 2009- The geology of Khuff outcrop analogues in the Musandam Peninsula, United Arab Emirates and Oman. GeoArabia. v. 14: p.125–158
Maurer, F., Rettori, R. & Martini, R., 2008- Triassic stratigraphy, facies and evolution of the Arabian shelf in the northern United Arab Emirates. Int J Earth Sci (Geologische Rundschau), v. 97: p.765–784
Moradpour, M., Zamani, Z. & Moallemi, S. A., 2008- Controls on reservoir quality in the lower Triassic Kangan Formation, Southern Persian Gulf. Jour Petrol. Geol., 31, 367-385.
Navabpour, P., Angelier, J. & Barrier, E., 2007- Cenozoic post-collisional brittle tectonic history and stress reorientation in the High Zagros Belt (Iran, Fars Province), Tectonophysics 432 (2007).  p. 101–131.
 Peyravi, M., Kamali, M. R. & Kalani, M., 2010- Depositional environments and sequence stratigeraphy of the early Triassic Kangan Formation in the northern part of the Persian Gulf: Implications for reservoir characteristics. Journal of Petroleum Geology. v 33, 4, p. 371-386.
Purser, B. H. & Evans, G., 1973- Regional sedimentation along the TrucialCoast, SE Persian Gulf. In: PURSER, B.H. (ed.) The Persian Gulf. Springer, Berlin, p.211-231.
Rahimpour-Bonab, H., 2007- A procedure for appraisal of a hydrocarbon reservoir continuity and quantification of its heterogeneity. Journal of Petroleum Science and Engineering, v.58, no. 1-2, p. 1-12.
Rahimpour-Bonab, H., Asadi-Eskandar, A. & Sonei, R., 2009- Permian–Triassic boundary and its control over reservoir characteristics in South Pars gas field, Persian Gulf. Geological Journal, 44, p.341–364.
Rahimpour-Bonab, H., Esrafili-Dizaji, B. & Tavakoli, V., 2010- Dolomitization and anhydrite in permo-triassic carbonatesat the south pars gasfiled offshore Iran: controls on reservoir quality. Jourrnal of Petroleum Geology, v 33(2), p1-24.
 Read, J. F., 1985- Carbonate Platform Facies Models. AAPG Bulletin 69/1, p. 1–21.
Reading, H. G., 1996- Sedimentary environments: processes, facies and stratigraphy. 3rd ed., Blackwell, p. 688.
Sharland, P. R., Archer, R., Casey, D. M., Davies, R. B., Hall, S. H., Heward, A. P., Horbury, A. D. & Simmons, M. D., 2001- Arabian plate sequence stratigraphy: GeoArabia Special Publication. 2, p.371.
Shinn, E., 1983- Tidal Xats. In: Scholle, P.A., (Eds.), Carbonate depositional environments. American Association of Petroleum Geologists Memoir 33, pp. 171–210.
Stampfli, G. & Borel, G. D., 2002- A plate tectonic model for the Palaeozoic and Mesozoic constrained by dynamic plate boundaries and restored synthetic oceanic isochrones. Earth Planet. Sci. Lett. 196, p.17–33.
Strohmenger, C. J., S. Alway, R. H., W.Broomhall, R., Hulstrand, R. F., Al-Mansoori, A., Abdalla, A. A. & Al-Aidarous, A., 2002- Sequence stratigraphy of the Khuff Formation comparing subsurface and outcrop data (Arabian plate, U.A.E.): Society of Petroleum Engineers, SPE Paper 78535.
Tucker,  M. E. & Wright, V. P., 1990- Carbonate sedimentology. London, Blackwell Scientific Publications, p.482.
Tucker,  M. E., 1993- Carbonate diagenesis and sequence stratigraphy. Sedimentology. Reviews 1, p. 51-72.
Tucker, M. E., 2001- Sedimentary petrology, Third edition, Blackwell, Oxford, p. 260.
Warren, J. K., 2006- Evaporites­: sediments, resources and hydrocarbons. Springer Verlag, Brunei, p.1035.
Wilson, J. L., 1975- Carbonate facies in geological history. Springer, Berlin–Heidelberg, New York. p. 471.