poster of japon

The 14th Formation Evaluation Symposium of Japan, September 29-30, 2008

-1-

Poroperm controlling factors in Khuff strata, South Pars gas field, offshore Iran

B. Esrafili-Dizaji1, H. Rahimpour-Bonab1, V. Tavakoli1

1.Department of Geology, College of Science, University of Tehran, Iran ([email protected])

This paper was selected for presentation by the JFES program committee following the review of abstract submitted by author(s). ABSTRACT The South Pars Field, discovered in 1990, is part of world's largest single gas accumulation that located in Persian Gulf. Facies analysis in the Permotriassic reservoir of this field shows that its depositional setting was located along inner part of a homoclinal ramp or epiric carbonate system and extended from a peritidal setting to a shallow subtidal zone, passing over a high energy shoal and offshoal facies. Petrographycal and geochemical (stable isotopes of bulk samples) evidences all indicate that these facies were mainly exposed to a shallow diagenesis and minor subsequent burial. Hypersaline and meteoric diagenetic realms were two well identified zones in the reservoir intervals. Detailed investigation along with correlation of poroperm values with textures and facies, lithology and mineralogy, pore types and relative frequency (pore facies analysis), volume of cements, frequency of stylolite and fractures showed that six key factors are generally controlling distribution of porosity and permeability in these reservoirs: 1) the reservoir production potential depends originally upon the cumulative thickness of grain dominated textures and facies. 2) Early dolomitization (Sabkha and Reflux model) has minor effects on the precursor limestone poroperm values, but dolomite neomorphism has improved the porosity-permeability relationship. 3) Anhydrite and calcite cementations decrease poroperm values. 4) Dissolution along with leaching of the metastable grains and cements has created the main reservoir quality zones. More than 60 percent of pores have been created by dissolution. 5) Compaction and specially stylolite generation had important effects on the reservoir quality decrease. 6) Fracturing has increased the poroperm values but are not well-extended. Finally distal diagenetic facies of reservoir rock has 9% porosity and 26 md permeability in average. INTRODUCTION In recent years, many challenges exist in characterizing, quantifying, and predicting carbonate reservoir quality. It is widely accepted that carbonate reservoirs may be inherently heterogeneous in nature at a variety of scales (e.g. Nurmi et al., 1990; Mazzullo and Chilingarian, 1992; Russell et al., 2002; Smith et al., 2003).

Fig. 1. Map showing the location of South Pars fields and studied wells in the Persian Gulf, offshore Iran.

The Khuff Formation in the Middle East is one of the most important and prolific reservoir units. This carbonate-evaporite succession is hosting numerous gas fields (Khuff reservoirs) in the Persian Gulf basin (Alsharhan and Nairn, 1997; Bordenave, 2008). In addition, it hosts the world’s largest gas reserve in the North Dome/South Pars fields (discovered 1971 and 1990, respectively) which extends over the Iranian and Qatari offshore (Ehrenberg et al, 2007) (Fig. 1). The main goal of this study is to characterize and illustrate depositional and diagenetic controls over reservoir quality. The description and quantification of reservoir heterogeneities require integration of depositional, diagenetic and petrophysical data at various scales.


-2-

GEOLOGICAL SETTING 1. TECTONIC FRAMEWORK During most of the geologic time Persian Gulf basin were separated by a positive paleostructure, Qatar Arch, into two troughs at the east-southeast (Rub-Al-Khali in the United Arabian Emirates, U.A.E.) and the west-northwest (central part of the Persian Gulf basin)(-Alsharhan and Nairn, 1997; Konert et al., 2001; Ziegler, 2001; Konyakhov and Maleki, 2006). This Arch is a north-northeast trending positive tectonic feature, extending into the Persian Gulf and effectively dividing it into two basins. In fact, this major tectonic element of the Arabian plate tectonic setting is a regional gentle and broad anticline (Fig. 2), that extending from the Arabian Peninsula. It had a fundamental influence on the tectonic patterns and sedimentation history of the Gulf (Alsharhan and Nairn, 1997; Konert et al., 2001; Ziegler, 2001; Konyakhov and Maleki, 2006). North Field and South Pars are located on the north-northeast plunge of this Arch (Figs. 1, 2).

Fig. 2. Cross section of sedimentary covers from the Central Arabian Arch to the Persian Gulf region. (Compiled after Konert et al., 2001). Thinning of the Permian sediment indicates the existence of a syn-depositional structural high in SE of the Zagros, a trending block-faulted horst within the basement, known as the Qatar Arch. The post-Paleozoic tectonic activity revived this structural high, as witnessed by some erosion of the Triassic units (Szabo and Kheradpir, 1978; Saint-Marc, 1978; Murris, 1980; Kashfi, 1992).

The Qatar-South Pars Arch was a positive structure during the Paleozoic and gradually subsided during Jurassic times (Saint-Marc, 1987). It has been active periodically throughout the Mesozoic and Cenozoic time, including the late Tertiary when sediments currently exposed on the Arch were deposited (Konert et al., 2001; Ziegler, 2001; Alsharhan and Nairn, 1997; Konyakhov and Maleki, 2006). 2. STRATIGRAPHIC SETTING Stratigraphic successions that formed important hydrocarbon systems in the subsurface of the Qatar Arch, are well-documented and cropped out in the fold belts in the east and north of the Arabian Plate in the Oman and Zagros Mountains (Sharland et al. 2001; Ziegler, 2001; Alsharhan and Nairn, 1997; Alavi, 2004). In Permo-Triassic two megasequences III and IV (include Faragan, Dalan, Kangan and Dashtak Formations) are deposited in the newly opened ocean (Neotethys). Dalan and Kangan Formations in the Zagros area, the lateral equivalent of the well-known Khuff strata, are extended in large parts of the Arabian plate (Fig. 3). Today, these sequences are hosting huge gas reserves in both North Field and South Pars in the Persian Gulf basin (Ehrenberg et al, 2007). These reservoir rocks are conformably overlain by the rusty-brown or varicolored Aghar Shales in the base of the Dashtak Formation that act as seal in the Qatar Arch huge petroleum system (Alsharhan and Nairn, 1997; Sharland, 2001; Aali et al., 2006; Bordenave, 2008).

Fig. 3. Generalized stratigraphy of the South Pars Field showing formation lithology, Erosional surface detected from seismic survey; Four rock group in this area are recognized according Alavi (2004) (No to scale).


-3-

DATA BASE AND METHODS This paper is mainly based on the examinations of subsurface data across the Iranian domain of the world’s largest single gas accumulation, South Pars field. The main approach in this study is to examine poroperm controlling factors in the South Pars reservoir units in both large and fine scales. In the large-scale, on the base of cores, thin sections, geochemical data (δ18OPDB and δ13CPDB), logs, core plugs and petrophysical analyses, rocks of the Upper Khuff were analyzed to reveal poroperm controlling factors. These factors are, in turn, controlled by combination of primary depositional textures and secondary diagenetic features. On the microscopic scale, image analysis software is used for Digital Point Counting (DPC) to determine the relative proportions of different pore types in 68 thin sectioned samples. From each thin section some 6 to 10 photos are taken for this method. Under the pore facies scheme, these data are compared and calibrated by core poroperm values. FACIES ANALYSIS AND SEDIMENTARY ENVIRONMENT Combined core examinations and detailed thin section studies are used for facies analysis. Accordingly, 14 major facies were recognized in the Upper Khuff reservoir in the field. They are grouped as five facies assemblages deposited in supratidal, intertidal, lagoon, shoal and off-shoal environments (Fig. 4). The lateral distribution along the carbonate system is reconstructed, extending from a peritidal setting to a shallow subtidal zone passing over a high energy shoal facies (Fig. 4). Upwards, with transitional boundary, a consistent gradational change from shallow to deep water facies is seen that contain thick sections of shallow water facies. The temporal distribution of these facies associations reflects an ideal shallowing upward sequence. These facies are genetically related and indicate gentle depositional gradient and morphology during deposition. Thus, they represent shallow part of a homoclinal carbonate ramp (Fig. 4). This interpretation is based on the characteristics of the constituting facies, lateral and vertical relations between sedimentary facies, the presence of thick succession of shallow deposits (high relative proportion of peritidal and lagoon vs. open marine facies), absence of reef and mass flow deposits (re-sedimented deposits) associated with a shelf break (margin) and low diversity in facies type (Ahr, 1973 & 1998; Read, 1985; Burchette and Wright 1992; Wright and Burchette, 1998). Development of this ramp system is favored with prevalence of suitable paleotectonic and paleogeographic conditions and absent of worldwide reef building organisms in the Late Permian-Early Triassic (Burchette

and Wright, 1992; Wright and Burchette, 1996).

Fig. 4. Generalized depositional model for the Khuff strata in the field scale. DEPOSITIONAL CONTROLS ON RESERVOIR PROPERTIES Considering relationships between depositional textures and reservoir properties could provide information regarding paleoenvironmental controls. Correlation of depositional textures and poroperm data provides two important results: 1) A close correlation is found between grain-dominated facies (such as grainstone, grain-dominated packstone and mud-dominated packstone) and their cumulative thickness, with poroperm data. In fact, as shown in figure 5, production potential in this field is a function of depositional environment energy and relative proportions of grain to mud. 2) In muddy intervals of reservoir successions in this field, positive correlation between grain-dominated intervals and their cumulative thickness with productive zones are commonly well-preserved in both limestone and dolomite. The grain types and fabrics of each facies are interpreted to reflect a specific depositional environment and energy range. Energy conditions during deposition played a major role in determining primary porosity by controlling grain types, sizes, and sorting. Besides, grain-dominated units are susceptible to secondary porosity development and increase in reservoir qualities, due to dissolution of unstable grains (ooids and bioclasts) and persistence of low Mg-calcite matrix. Considering the results of this investigation, it could be expected that grain-dominated apart from their diagenetic history, should have high reservoir qualities as they have formed the main reservoir intervals. In other words, mud-dominated facies acted as seals while grain-dominated facies shows reservoir characters. In addition, there is a positive correlation between reservoir quality and other textural parameters. Scatter plots of core analysis data versus depositional facies association suggest that subtidal facies (open lagoon, shoal and offshoal facies) have the highest reservoir quality, always higher than production cutoff (φ>5% and K>0.1 md) (Fig. 6). Supratidal and intertidal facies show variable permeability and lower porosities values than subtidal facies. In some intervals, intertidal facies are replaced by fabric-preserving, fine crystalline


-4-

Fig. 5. Positive correlation between grain-dominate intervals and its cumulative thickness with productive zones apart from their lithology. dolomite (anhedral crystals). Main porosity types are fenestral, intercrystalline and fractures. Few samples show high permeability values (coarse crystalline, dolomitic facies of supratidal and intertidal that fractured). In most cases, range of poroperm values coincide with environmental energy gradient and increase from land to high-energy shoal setting and decrease in offshoal facies. However, differences do arise which are because of the diagenetic overprints (Cantrell and Hagerty, 2003; Kostic and Aigner 2004). Depositional textures and facies are important in determining reservoir rocks (both limestone and dolomite) porosity and permeability in the subsurface. Although subjected to a complicated history of diagenetic modification, reservoir quality in the South

Fig. 6. Poroperm values of each facies association indicating effects of the environmental energy on the distribution of reservoir properties. Pars Field is closely linked to the depositional facies (Figs. 5 and 6). DIAGENETIC HISTORY AND POROSITY EVOLUTION The reservoir has been subjected to the complex diagenetic events that could be ascribed to two diagenetic regimes (Fig. 7): (1) early diagenesis (before the onset of pressure-solution) and (2) late diagenesis (during and after the pressure-solution). Most of the reservoir creating diagenesis occurred in shallow-burial (meteoric realm). Major portion of porosity in the reservoir is secondary in origin, formed during diagenesis and ranges from 0 to 36%. Detailed petrographic examinations denote selective diagenesis in the reservoir. Evidences for dissolution of aragonite and preservation of low Mg-calcitic matrix suggest evolution of secondary porosity in these carbonates. Although dolomitization, dolomite neomorphism and fracturing have had minor effects on the porosity generation, but in some cases, they have exerted major control on the permeability values. Considering reservoir quality, burial diagenesis had mainly lowest effects on the reservoir quality. Its effects include physical compaction, anhydrite precipitation (remobilized cements) and carbonate cementation (apart from minor porosity generation through dolomite neomorphism,stylolitization and fracturing). Hypersaline and meteoric diagenetic realms were two well identified zones in the reservoir intervals.


-5-

Fig. 7. Diagenetic sequences and porosity evolution in the Upper Khuff carbonates in South Pars field. Based on petrographic examinations, evolution of porosity is mainly related to the diagenetic processes. DIAGENETIC CONTROLS ON RESERVOIR QUALITY 1. MENERALOGY AND LITHOLOGY Calcite, dolomite and anhydrite are three common mineralogy of the reservoir observed in stained thin sections. Facies selective diagenesis in hypersaline conditions leads to dolomite formation and anhydrite mineralogy in peritidal and restricted marine facies and settings. Association of these two mineralogies is related to the sea water evaporation which is addressed in many case studies (e.g. Qing et al., 2001; Melim and Scholle, 2002). Correlation of reservoir rocks mineralogy with poroperm data indicated that there is close relationship between mineralogy/lithology and reservoir quality (Fig. 9). In fact, stratigraphic positions of pay intervals are defined by rock composition (Fig. 9), i.e., reservoir intervals have positive correlation and association with limestone and dolomitic limestone intervals. In other words, anydritic dolomite, dolomite and anhydrite units are mostly associated with nonpay (tight) intervals. 2. DOLOMITIZATION AND DOLOMITE NEOMORPHISM Figure 8 displays relation between stable isotopic compositions (δ18OPDB) of bulk rock samples vs. poroperm values in the Upper Khuff unit. As seen, there is almost positive correlation between low oxygen isotope values and porosity. Also, limestone intervals are porous than the dolomite units (Fig. 8). In other words, porosity is decreasing with increase in degree of

dolomitization. But in general, permeability values of dolomite units are better than the limestone intervals. Effects of dolomitization in connecting pore spaces are revealed in figure 21. Dolostones with light stable oxygen isotopic compositions (δ18OPDB <0 ‰) and coarse crystalline texture (neomorphic dolomites) have higher permeability values than both limestones and other dolomites. In general, dolomite neomorphism associated with crystal size increasing has good effects on the reservoir quality of dolostones. Although, dolomitization and dolomite neomorphism had improving effects on the permeability of dolostone units, but, apparently it is mostly controlled by precursor sediments fabrics and the original porosity (Fig. 12). As seen in figure 12, poroperm values of reservoir rocks are affected mainly by grain/mud ratio (energy of environment). In some cases, impacts of dolomitization on muddy intervals were positive and have increased poroperm values that addressed by Lucia (2004) previously. Therefore, it could be deduced that dolomitization has insignificant effect on the porosity generation but it has improved permeability of dolostones.

Fig. 8. Plot of poroperm vs. stable isotope composition (δ18O) in the Upper Khuff member, South Pars field. In general, δ18O values decrease (decreasing dolomitization degree) with increasing porosity. There is complexity about permeability and δ18O values.


-6-

Fig. 9. Relationship between lithology/mineralogy and poroperm data. Generaly, limestone lithologies mostly associated with high porosity intervals but low porosity units coincide with dolomite and anhydrite intervals. 3. DISSOLUTION Petrographic observations showed that dissolution is the most important factor in porosity creation in the South Pars field. Sedimentary particles remained mostly unaffected by dolomitization (limestone facies) and were subjected to dissolution to variable degrees. These particles originally were composed of ooids and bioclasts, as is suggested by the size and shape of the remaining dissolution molds. Considerable porosity (more than 80%) in the reservoir rocks was produced during dissolution of aragonitic components. Fabric-selective early dissolution of unstable grains is created moldic pores, which are the dominant pore types in this field. In some cases, dissolution of anhydrite cements created pseudo-intercrystalline pores, which are the dominant pore types.

Near-surface leaching processes (tied to meteoric cementation) are mostly associated with limestone intervals, because early dolomitized sediments are more stable than the limestone in meteoric conditions (Moore, 2001). As result of this, effects of this differential dissolution in dolomitic units are only local. Therefore, original mineralogy is highly affected degree of dissolution and spatial distribution of the reservoir zones. Secondary dissolution porosity and also permeability were closely related to depositional facies. The close association between meteoric dissolution and open marine facies are predominant feature in reservoir rock. In pore scale studies, 68 samples are selected from reservoir intervals that have commercial poroperm values (φ>5% and K>0.1 md) (fig. 7). Digital point counting of these samples indicated eight basic pore


-7-

types (Fig. 10). Relative proportions of these pore types for each sample is plotted on this triangle and the poroperm relationships of samples are compared with Lucia’s petrophysical classes (Lucia, 1999) (Fig. 10). Studies are showed more than 60 percent of pores have been created by dissolution.

Fig. 10. Pore facies analysis (according to Ahr and Hommel, 1999) and its poroperm values in lucia's petrophysical classification (Lucia, 1999). Most of pores have diagenetic (dissolution) origin. 4. CEMENTATION Two major types of cements that occurred in porous facies of reservoir rocks are anhydrite and calcite cements. Both cement types (degree of cementation) show an inverse relationship with porosity and permeability. Early cementation processes is higher than late cementation phase, volumetrically. A direct relationship exists

between the original depositional environment and the early diagenetic processes that formed most of the pore-plugging cements (selective cementation). Anhydrite cements are mostly associated with dolomite intervals (supratidal, intertidal and lagoon facies), instead, calcite cements are associated with limestone intervals that include open marine facies. Visual estimations indicate that the most prevalent type of cements in reservoir intervals is anhydrite. Cements (particularly anhydrite) commonly have negative effect on poroperm values. For examination of anhydrite pluging effect, a function “Anhydrite index” was constructed to represent the decreasing of poroperm values with increasing of anhydrite plugging index (AI = 100 × anhydrite/total carbonate) (fig. 11). In many cases, pore spaces are completely occluded by cementation. Although negative effects of cementation on reservoir quality is dominant in reservoir rocks but in some cases this process (especially calcite cement) have positive influence on preservation of porosity. In well-cemented shoal facies, marine calcite spars hindered post-compaction effects and decrease of porosity. Cementation is the dominant mechanism of porosity loss in the studied reservoir rock. The precipitation of the main porosity occluding cements (calcite, anhydrite) occurred early in the diagenetic history (based on visual evaluation).

Fig. 11. Crossplot of poroperm data and “Anhydrite index” function. There are a good overall inverse correlation between poroperm values and anhydrite plugging index (AI = 100 × anhydrite/total carbonate). 5. COMPACTION Compaction has affected reservoir rocks in this field from deposition through deep burial. Most depositional


-8-

Fig. 12. Relationship between poroperm data and frequency of stylolite in the South Pars field at the reservoir scale. As seen in this log, stylolite present in both reservoir and nonreservoir intervals, but frequency of these features increase in nonreservoir units. In other word, distance of stylolite in reservoir units are more than nonreservoir intervals

fabrics show little evidence of compaction prior to dolomitization, suggesting dolomitization process prior to compaction. It seems that mechanical and chemical compaction during burial has reduced porosity in the reservoir rocks. As a result of increasing compaction (extensive chemical compaction), solution seams and stylolites are developed. Stylolites truncate dolomite and anhydrite crystals, but dolomite and anhydrite were not observed overgrowing stylolites.. In general, both negative and positive aspects vs. poroprm data are recognized in literatures (Longman, 1982; Scoffin, 1987; Tucker and Wright, 1990). Core observations and thin section analysis indicate that stylolite present in both reservoir and nonreservoir intervals, but frequency of these features increase in nonreservoir units. In other word, distance of stylolites in reservoir units is more than nonreservoir intervals (Fig. 12). Quantitative data shows that 3% of pore types in the reservoir rock are stylolitic. The latter pores are connected other pores and have positive effects on reservoir quality. Apparently negative aspects of this diagenetic process are predominant in the South Pars field, as frequently reported from other hydrocarbon fields. Results of this study are supported by Ehrenberg (2006) findings in the South Pars field. 6. FEACTURING Fractures and microfractures have local importance in reservoir rock and in many cases these are filled by anhydrite, calcite and saddle dolomite cements (Mineralized or closed fractures). Open fracture system connects otherwise unconnected porosity. Natural fractures are separated from drilling or laboratory-derived fractures during systematic fracture analysis. Their features can be visually identified at the all scales on core samples or borehole electrical images. In general, visual evaluation of fracture-connected porous core samples showed that they have high permeability values. In this regard, fractures density in the reservoir rock is important. Precise role of fractures in the reservoir quality is not yet understood and is not well studied. However, reservoir quality may be enhanced in certain intervals of a field by natural fracturing because fracture porosity is an important contributor to permeability in many carbonate reservoirs (Lucia, 1999). 7. DISCUSSION AND CONCLUSION Depositional-diagenetic reservoir heterogeneities in the Upper Khuff strata in the South Pars field have different origin, in variety of scales. Several factors controlled large-scale heterogeneity of porosity distribution in the Upper Khuff carbonate platform that discussed here. Original depositional texture, mineralogy and lithology, dolomitization and


-9-

dolomite neomorphism, cementation, dissolution, compaction and fracturing are main in this regard. In general, at the large-scale, the reservoir quality is inherited from paleoplatform and its stratigraphic evolution. In this scale, all diagenetic processes such as followed depositional patterns thus have stratified distributions. Therefore, stratigraphic position and its continuity in both lateral and vertical scales are mainly determined by depositional processes. In other word, reservoir potential that is controlled by depositional factors and paleoenvironmental conditions exerted main effects on the reservoir quality. Changes of the depositional environment with time and space lead to the isolation of pay zones between tight lithologies. Presence of anhydrite and anhydritic dolomudstones near the third-order sequence boundary turnaround is very effective in this regard. In terms of origin, core observation, thin section analysis and quantitative digital point counting showed that reservoir quality is primarily the result of shallow diagenesis. As result of this, small scale reservoir heterogeneity in the reservoir rocks is a function of intensity of facies-selective diagenesis. In fact, degree of diagenetic gradient dictates degree of connectivity of pore systems in porous intervals. In conclusion, porosity and reservoir qualities were controlled by primary depositional facies (geometry and grain composition of high-energy shoals; anhydrite and micritic interformational seals) and facies-selective diagenesis (freshwater dissolution of ooids, porosity destruction processes). References Ahr, W. M., 1998, Carbonate ramps, 1973–1996: a historical review Geological Society, London, Special Publications, v. 149; p. 43-53. Ahr, W.M., 1973. The carbonate ramp: an alternative to the shelf model. Trans-Gulf Coast Assoc Geol Soc. 23, 221– 5. Ahr, W.M., Hammel, B., 1999, Identification and mapping of flow units in carbonate reservoirs: An example from Happy Spraberry (Permian) field, Garza County, Texas, U.S.A.. Energy Exploration and Exploitation. 17, 311–334. Alavi, M., 2004, Regional stratigraphy of the Zagros fold-thrust belt of Iran and its proforeland evolution. American Journal of Science. 304, 1–20. Alsharhan, A.S., 2006, Sedimentological character and hydrocarbon parameters of the middle Permian to Early Triassic Khuff Formation, United Arab Emirates. GeoArabia. 11, 121–158. Alsharhan, A.S., Nairn, A.E.M., 1997. Sedimentary Basins and Petroleum Geology of the Middle East. Elsevier, Netherlands. 843 pp. Bordnave, M.L., 2008, The origin of the Permo-Triassic gas accumulations in the Iranian Zagros foldbelt and contiguous offshore area: a review of the Paleozoic

petroleum system. J. Pet. Geol. 31, 3–42. Burchette, T.P., Wright, V.P., 1992, Carbonate ramp depositional systems. Sedimentary Geology. 79, 3–57. Buxton, M.W.N., Pedley, H.M., 1989, Short paper: a standardized model for Tethyan Tertiary carbonate ramps. Journal of the Geological Society (London). 146, 746– 748. Cantrell, D.L., Hagerty, R.M., 2003, Reservoir rock classification, Arab-D reservoir, Ghawar field, Saudi Arabia. GeoArabia. 8, 435-462. Chilingarian, G.V., Mazzullo, S.J., Rieke, H.H., 1992, Carbonate Reservoir Characterization: A Geologic-Engineering Analysis, Part I: Elsevier Publ. Co., Amsterdam, Developments in Petroleum Science 30, p. 199-270. Ehrenberg, S. N., 2006, Porosity destruction in carbonate platforms. Journal of Petroleum Geology. 29, 41–52. Ehrenberg, S.N., Nadeau, P.H., and Aqrawi, A.A. M., 2007. A comparison of Khuff and Arab reservoir potential throughout the Middle East. AAPG Bulletin, 86. 1709–1732. Kashfi, M.S., 1992, Geology of the Permian ‘supergiant’ gas reservoirs in the greater Persian Gulf area. J. Pet. Geol. 15, 465–480. Konert, G., Afifi, A.M., AL-Hajari, S.A., Droste, H., 2001, Paleozoic stratigraphy and hydrocarbon habitat of the Arabian Plate. GeoArabia. 6, 407–442. Konyuhov, A. I., Maleki, B., 2006, The Persian Gulf Basin: Geological History, Sedimentary Formations, and Petroleum Potential. Lithology and Mineral Resources. 41, 344–361. Kostic, B., and T. Aigner, 2004, Sedimentary and poroperm anatomy of shoal-water carbonates (Muschelkalk, South-German basin), an outcrop-analogue study of inter-well spacing scale: Facies. 50, 113–131. Longman, M.W., 1982, Carbonate diagenesis as a control on stratigraphic traps. Am. Ass. Petrol. Geol.Edue. Course Note Series, 21, pp.159. Lucia, F. J., 1999, Carbonate reservoir characterization: New York, Springer, 226 p. Mazzullo, S.J., Chilingarian, G.V., 1992, Diagenesis and origin of porosity, In: G.V. Chilingarian, S.J. Mazzullo, and H.H. Rieke, eds., Carbonate Reservoir Characterization: A Geologic-Engineering Analysis, Part I: Elsevier Publ. Co., Amsterdam, Developments in Petroleum Science 30, p. 199-270. Melim, L.A., Scholle, P.A., 2002, Dolomitization of the Capitan Formation forereef facies (Permian, West Texas and New Mexico): seepage reflux revisited. Sedimentology 49, 1207– 1227. Moore, C. H., 2001, Carbonate reservoirs porosity evolution and diagenesis in a sequence stratigraphic framework: Amsterdam, Elsevier, 444 p. Murris, R.J., 1980, Middle East: Stratigraphic evolution and oil habitat. American Association of Petroleum Geologists Bulletin 64, 597–618. Nurmi, R., Charara, M., Waterhouse, M., Park, R., 1990,


-10-

Heterogeneities in carbonate reservoirs: detection and analysis using borehole electrical imagery, In: Hurst, A., Lovell, M. A., Morton, A. C., (eds), 1990. Geological Applications of Wireline Logs Geological Society Special Publication No. 48, pp. 95-111. Qing, H., Bosence, D.W.J., Rose, P.F., 2001, Dolomitization by penesaline seawater in early Jurassic peritidal platform carbonates, Gibraltar, western Mediterranian. Sedimentology 48, 153– 163. Read, J.F., 1985. Carbonate platform facies models. AAPG Bulletin 69/1, 1–21. Russell, S.D., Akbar, M., Vissapragada, B., Walkden, G.M., 2002, Rock types and permeability prediction from dipmeter and image logs: Shuaiba reservoir (Aptian), Abu Dhabi. Journal of Petroleum Geology. 86, 1709–1732. Saint-Marc, E., 1978, Arabian Peninsula, In: Moullade, M., and Nairn, A. E. M., eds., The Phanerozoic geology of the world II: The Mesozoic: Amsterdam, Elsevier, p. 435-462. 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, vol. 2. Gulf PetroLink, Bahrain. 371 pp. Scoffin, T.P., 1987, An introduction to carbonate sediments and rocks, Blackia and Son Ltd, Glasgow, 274pp. Smith, L.B., Eberli, G.P., Masaferro, J.L., Al-Dhahab, S., 2003, Discrimination of effective from ineffective porosity in heterogeneous Cretaceous carbonates, Al Ghubar field, Oman. AAPG Bull. 87, 1509–1529. Szabo, F., Kheradpir, A., 1978, Permian and Triassic stratigraphy, Zagros basin, South-West Iran. J. Pet. Geol. 1, 57–82. Tucker, M. E., Wright, V. P., 1990, Carbonate sedimentology. London, Blackwell Scientific Publications, 482 p. Wardlaw, N.C., 1979, Pore systems in carbonate rocks and their influence on hydrocarbon recovery efficiency, Am. Ass. Petrol. Geol, Continuting Education Course Notes, 11, E1-E24. Wright, V.P., Burchette, T.P., 1998. Carbonate Ramps. Geological Society of London, Special Publication, vol. 149, pp. 137– 161. Ziegler, M., 2001, Late Permian to Holocene Paleofacies Evolution of the Arabian Plate and Its Hydrocarbon Occurrences, GeoArabia, vol. 6, no. 3, pp. 445–504.

Behrooz Esrafili-Dizaji Behrooz Esrafili-Dizaji did undergraduate studies at the University of Zanjan (2001–2005), received a Master’s degree from University of Tehran in 2008. His research interests included carbonate sedimentology, diagenesis, and reservoir characterization. Hossain Rahimpour-Bonab Hossain Rahimpour-Bonab received his B.S.c degree in geology from University of Tehran in 1988, and his M.S.c degree in Sedimentology from the University of Tehran in 1991 and a Ph.D. in Geology (geochemistry) 1997 from University of Adelaide, Australia. He teaches courses related to sedimentary geochemistary and also sedimentary environmet and diagenesis in carbonate rocks. Vahid Tavakoli Vahid Tavakoli received his B.Sc. and M.Sc. degrees in geology from the University of Tehran in 2002 and 2005, respectively. His principal area of research is on log analysis and reserevoir characterization of carbonates and siliciclastic rocks. He is presently Ph.D student in sedimentology in University of Tehran.

poster of japon

Documents