Study of pore system in relation to reservoir characteristics of the upper Dalan and Kangan formations in Lavan field, south east of the Persian Gulf

Document Type : Research Paper

Authors

Abstract

Carbonate Dalan and Kangan formations with the late Permian-early Triassic age are considered as the main gas reservoir rocks in some fields of the Persian Gulf. Carbonate facies of these formations which are related to shoal, lagoon and tidal flats have been developed in a carbonate ramp environment under the arid climate condition. Pores system of the formations under the effect of the primary depositional texture and diagenesis, has a significant control on the reservoir properties. In this study, in order to investigate the effects of these agents on the reservoir quality, hydraulic flow units were described. Then, based on the relationship between the identified hydraulic flow units and depositional and diagenetic characteristics, pores system of the reservoir facies was classified into four classes of porosity-permeability values of high, low, intermediate and high porosity-low permeability. The results show that the diagenetic processes such as dissolution, cementation, dolomitization and to some extent fracture, on the basis of the primary depositional texture, have the important effect on pore system distribution within the reservoir facies, and their reservoir properties. As, pervasive cementation by anhydrite and calcite have been associated with a severe decrease in reservoir quality of grain supported facies. In contrast, dissolution with creation of moldic and vuggy porosity has been acted in a way to change, improve or increase the reservoir quality. Also, in some parts of the reservoir, dolomitization by creation of intercrystalline porosity, and fracture especially in mudstone facies have been improved the reservoir quality.

Keywords


[1]  کدخدائی ایلخچی، ر.­، رحیم­پور بناب، ح.، کدخدائی ایلخچی، ع (1390) فاکتورهای کنترل­کننده بافت­های مختلف سیمان انیدریت و ارتباط آن­ با کیفیت مخزنی در مخازن کربناته دالان بالایی و کنگان­،­ نشریه پژوهش­های چینه­نگاری و رسوب­شناسی دانشگاه اصفهان، سال بیست و هفتم، شماره پیاپی 42، شماره اول، صفحات 26-1­.
[2]  کدخدائی ایلخچی، ر (1386) بررسی اثرات دیاژنزی بر روی ویژگی­های مخزنی بخش فوقانی سازند دالان و سازند کنگان با نگرشی ویژه بر اثر انیدریت بر کیفیت مخزنی در میدان پارس جنوبی­، پایان­‌نامه کارشناسی­ارشد، دانشگاه تهران، 127ص.
[3]  کـدخدائی ایلخـچی، ر (1395) مـطالعه یکـپارچـه سنگ­شناسی، محیط رسوبی و کیفیت مخزنی (با تاکید بر تفکیک گونه­های سنگی) مخازن کربناته کنگان و دالان در میادین ناحیه جنوب شرق خلیج­فارس، طرح پژوهشی حمایت شده توسط شرکت نفت فلات قاره ایران- پژوهش و فناوری، 84ص.
[4]  Abdolmaleki, J., Tavakoli, V., Asadi-Eskandar, A (2016) Sedimentological and diagenetic controls on reservoir properties in the Permian–Triassic successions of Western Persian Gulf, Southern Iran: Journal of Petroleum Science and Engineering, v. 141, p. 90-113
[5]  Aliakbardoust, E., Rahimpour-Bonab, H ­(2013) Effects of pore geometry and rock properties on water saturation of a carbonate reservoir: Journal of Petroleum Science and Engineering, v. 112, p. 296-309.
[6]  Aliakbardoust, E., Rahimpour-Bonab, H ­ (2013) Integration of rock typing methods for carbonate reservoir characterization: Journal of Geophysics and Engineering, v.­10, 055004 (11pp).
[7]  Al-Jallal, I.A (1987) Diagenetic Effects on Reservoir Properties of the Permian Khuff Formation in Eastern Saudi Arabia: SPE 15745, p. 465-475.
[8]  Alsharhan, A.S., Nairn, A.E.M (1994) ­The Late Permian carbonates (Khuff Formation) in the western Arabian Gulf: its hydrocarbon parameters and palaeogeographical aspects: Carbonates and Evaporites, v. 9, p.132-142.
[9]  Amaefule, J.O., Altnubay, M., Tiab, D., Kersey, D.G., Keeland, D.K (1993) Enhanced reservoir description: using core and log data to identify hydraulic (flow) units and predict permeability in uncored intervals/wells: Society of Petroleum Engineers, SPE 26436, 1-16.
[10]   Archie, G.E (1950) Introduction to petrophysics of reservoir rocks: American Association of Petroleum Geologists Bulletin, v. 34, p. 943-961.
[11]   Chehrazi, A., Rezaee, R., Rahimpour-Bonab, H (2011) Pore-facies as a tool for incorporation of small-scale dynamic information in integrated reservoir studies: Journal of Geophysics and Engineering, v. 8, p. 202-224.
[12]   Dunham­­­, R.J (1962) Classification of carbonate rocks according to depositional texture: American Association of Petroleum Geologists Memoir1, p. 108-121.
[13]   Ehrenberg, S.N (2006) Porosity destruction in carbonate platforms: Journal of Petroleum Geology, v. 29, p. 41-52.
[14]   Enayati-Bidgoli, A.H., Rahimpour-Bonab, H., Mehrabi, H (2014) Flow unit characterization in the Permian-Triassic carbonate reservoir succession at South Pars gasfield, offshore Iran: Journal of Petroleum Geology, v. 37(3), p. 205-230.
[15]   Esrafili-Dizaji B., Rahimpour-Bonab, H (2009) Effects of depositional and diagenetic characteristics on carbonate reservoir quality: a case study from the South Pars Gasfield in the Persian Gulf: Petroleum Geoscience, v. 15, p. 325-344.
[16]   Esrafili-Dizaji, B., Rahimpour-Bonab, H (2013) A review of Permo-Triassic reservoir rocks in the Zagros area, SW Iran: influence of the Qatar-Fars Arch: Journal of Petroleum Geology, Vol. 36(3), p. 257-279.
[17]   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.
[18]   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, p. 719-734.
[19]   Knaust, D (2009) Ichnology as a tool in carbonate reservoir characterization: A case study from the Permian-Triassic Khuff Formation in the Middle East: GeoArabia, Gulf PetroLink, Bahrain. v.14 (3), p. 17-38.
[20]   Koehrer, B.M., Zeller, T., Aigner, M., Poeppelreiter, M., Milroy, P., Forke, H., Al-Kindi, S (2010) Facies and stratigraphic framework of a Khuff outcrop equivalent: Saiq and Mahil formations, Al Jabal al-Akhdar, Sultanate of Oman: GeoArabia, v.15, p.91-156.
[21]   Mehrabi, H., Mansouri, M., Rahimpour-Bonab, H., Tavakoli, V., Hassanzadeh, M., Eshraghi, H., Naderi, M (2016) Chemical compaction features as potential barriers i n the Permian-Triassic reservoirs of South Pars Field, Southern Iran: Journal of Petroleum Science and Engineering, v. 145, p. 95-113.
[22]   Moradpour, M., Zamani, Z. Moallemi, S.A (2008) Controls on reservoir quality in the Lower Triassic Kangan Formation, Southern Persian Gulf: Journal of Petroleum Geology, v. 31, p. 367-386.
[23]   Peyravi, M., Kamali, M.R., Kalani, M (2010) Depositional environments and sequence stratigraphy of the Early Triassic Kangan Formation in the northern part of the Persian Gulf: Implications for reservoir characteristics: Journal of Petroleum Geology, v.33, p.371-386.
[24]   Rahimpour-Bonab, H, Aliakbardoust, E ­(2014) Pore facies analysis: incorporation of rock properties into pore geometry based classes in a Permo-Triassic carbonate reservoir in the Persian Gulf: Journal of Geophysics and Engineering, v.­11, 035008 (20pp).
[25]   Sfidari, E., Kadkhodaie-Ilkhchi, A., Rahimpour-Bbonab, H., Soltani, B (2014) A Hybrid approach for litho-facies characterization in the framework of sequence stratigraphy: A case study from the South Pars gas field, the Persian Gulf Basin: Journal of Petroleum Science and Engineering, v. 121, p. 87-102.
[26]   Tavakoli, V., Rahimpour-Bonab, H., Esrafili-Dizaji, B (2011) Diagenetic controlled reservoir quality of South Pars gasfield, an integrated approach: Comptes Rendus Geoscience, v. 343, p.55-71.
[27]   Ziegler, M (2001) Late Permian to Holocene Palaeofacies Evolution of the Arabian Plate and its Hydrocarbon Occurrences: GeoArabia, v. 6(3), p. 445-504.