سازند آسماری

Open Access Article

1 - Diagenesis, microfacies and determination of original carbonate mineralogy of the Asmari Formation in the southern flank of Rig anticline
Kakemem hamid mirmohammadsadeghi

The aim of this study is to recognize diagenetic processes, microfacies and geochemical evidence for original carbonate mineralogy of Oligocene- Miocene Asmari limestone deposited in the Rig anticline at Rig mountain oil field. In this area, the Asmari Formation with a More

The aim of this study is to recognize diagenetic processes, microfacies and geochemical evidence for original carbonate mineralogy of Oligocene- Miocene Asmari limestone deposited in the Rig anticline at Rig mountain oil field. In this area, the Asmari Formation with a thickness of 364 m have been exposed as a sequence of thin, medium, thick, and massive carbonate rocks. Twelve microfacies types have been distinguished on the basis of depositional textures, petrographic analysis and fauna. These carbonate microfacies belong to four major sub-environments including tidal flat, lagoon, bar/ shoal, and open marine. Absence of turbidite deposits, reefal belt and gradual changes in facies indicated that the Asmari Formation was deposited in a homoclinal carbonate ramp environment. The main diagenetic processes includes: dolomitization, cementation, micritization, dissolution, and compaction. Petrographic evidence and variation of major and minor element and compare this information with modern aragonite warm water and calcitic cool to cold temperate carbonate and originally aragonite mineralogy of Ordovician sub-tropical carbonate, the calcite mineralogy of Permian sub-polar cold water of Tasmania, the Upper Jurassic aragonite Mozduran limestone, the Ilam carbonate formation, and the Fahliyan Formation indicate that original carbonate mineralogy was aragonite in the Asmari Formation. High Sr/Na ratio suggests original aragonite mineralogy. Variation of Sr and Na values versus Mn confirm replacement of aragonite by calcite during the two stages of diagenetic stabilization. The bivariate plot of Sr/Ca versus Mn shows that Asmari limestone have been influenced by meteoric diagenesis in a closed to semi-closed diagenetic system. Manuscript profile

Open Access Article

2 - Factors controlling different types of anhydrite textures and their relation to reservoir quality in the Asmari reservoir in Ahvaz oil field
نسترن آزادبخت

Various diagenetic processes have affected reservoir quality of the Asmari Formation in Ahvaz Oil Field in wells No. 19 with a thickness of 357 meters. It is composed of limestone dolomite, dolomitic limestone, sandy dolomitic limestone, sandstone, siltstone and sha More

Various diagenetic processes have affected reservoir quality of the Asmari Formation in Ahvaz Oil Field in wells No. 19 with a thickness of 357 meters. It is composed of limestone dolomite, dolomitic limestone, sandy dolomitic limestone, sandstone, siltstone and shale. Study of 1100 thin sections from available cores at this well as well as the well’s numeral data, porosity and permeability of cores, indicates that the most important diagenetic processes is anhydritic cement with different types of textures. It appears as poikilotopic, porefilling and pervasive, nodular, fracture filling, sparce crystals, and evaporite veins. During different steps of diagenesis, these texture show replacement and pore filling porosity that have affected different facies to some degrees. Results of this study show that anhydrite cement occurs mainly in dolomitic and sandstone facies and to some extent, affected the reservoir quality. This is due to the effect of sulphate rich brines during dolomitization. Where the presence of anhydrite cements in limestone facies is sparse and rare, it has little effect on reservoir quality. However, pore filling and pervasive anhydrite texture filling all pore-space in dolograinstone and dolopackstone grain-supported facies during shallow burial intensively reduced reservoir quality. Dissolution of cements at later stage of diagenetic processes (creating secondary porosity) improved reservoir quality. In addition, solution of texture poikilotopic anhydrite in sandstone facies and repercipitated as patchy anhydrite with poikilotopic texture, results in reduction of porosity but it doesn’t make any changes in throat pores. Hence patchy anhydrite with poikilotopic texture that reduces porosity converts the sample from Lucias class 2 to class 1. Manuscript profile

Open Access Article

3 - Lithostratigraphy and biostratigraphy of the Asmari Formation in southern flank of Mish anticline (Tang-e-Ganaveh)
Farzad Moradi Abbas Sadeghi Hasan Amiri Bakhtiar

The Asmari Formation in the southern flank of Mish anticline (in the north of Gachsaran) with a total thickness of 366 m is mainly composed of medium to thick limestone layers. Based on lithological studies, it is mainly composed of a periodic arrangement of marly lime More

The Asmari Formation in the southern flank of Mish anticline (in the north of Gachsaran) with a total thickness of 366 m is mainly composed of medium to thick limestone layers. Based on lithological studies, it is mainly composed of a periodic arrangement of marly limestone with very thick, thick and medium bedded limestone layers and in some parts it consists of dolomitic layers. The lower contact of the Asmari Formation with Pabdeh Formation is gradual and its upper contact with the Gachsaran Formation is conformable with some sharp lithological changes. Based on change in thickness of layers, color and lithology, this carbonate sequence is subdivided into three lithological units. In Biostratigraphic studies, 28 species belonging to 41 genera of foraminifera were recognized. According to recognized biozone and foraminifera assemblages, 4 biozones and one undetermined zone were classified according to Laursen et al., 2009. The age of the Asmari Formation in this section is Oligocene (Rupelian-Chatian) to Early Miocene (Aquitanian-Bourdigalian). Manuscript profile

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4 - Reservoir zonation using discrimination of effective and ineffective porosity method in one of the SW Iranian oil Fields; a special look at resistivity logs
جواد هنرمند ژیلا رضائیان دلوئی ارسلان زینل زاده

Abstract In this paper, core samples from Upper carbonates (Miocene age) of the Asmari Formation in one of the SW Iranian oil fields were studied in macro and microscopic scale. Subsequently, results from core and thin section studies compared with core porosity and pe More

Abstract In this paper, core samples from Upper carbonates (Miocene age) of the Asmari Formation in one of the SW Iranian oil fields were studied in macro and microscopic scale. Subsequently, results from core and thin section studies compared with core porosity and permeability and petrophysical wireline logs, especially resistivity logs. Due to texture variation (mudstone to grainstone) and diagenetic events (dolomitization, dissolution, calcite and anhydrite cementation), porosity type and percentage changed in wide range in this formation. This study showed that resistivity logs could be used as an effective tool to distinct effective and ineffective-bearing zones. High permeability intervals have relatively high deep resistivity and high separation between deep and shallow resistivity logs, whereas non-reservoir intervals have low resistivity and very low separation between deep and shallow resistivity. Based on this study, studied carbonate interval of the Asmari Formation was divided into 13 zones. Using separation of deep and shallow resistivity logs, flow zones could be correlated throughout the studied field Manuscript profile

Open Access Article

5 - Propsing new approach for litho-facies modeling by use of Markov Chain method , an Iranian oil field
هانیه نیکو گفتار

Reconnaissance and interpretation of underground heterogeneity, particularly litho-facies,always plays an important role in evaluation and management of hy dro carbon resources.between various methods presented for modeling discrete characteristics of More

Reconnaissance and interpretation of underground heterogeneity, particularly litho-facies,always plays an important role in evaluation and management of hy dro carbon resources.between various methods presented for modeling discrete characteristics of hydrocarbon reservoies such as litho-facies ,One with a more proper con formity with actual condition of reservoie facies is of great ad vantage . formed on basis of pro bability and presenting transition matrix, markov method is widely applied as a powerful tools for modeling the facies .In the present study , first the method is introduced in details; then, in order to optimize it, suggestion is made based on changing the type of the move of chain in simulation procedure. the case study is a 12 km long 110 m thick section of Anhydrite and three major members of asmari Formation from an oil field, South-West Iran.This section is modeed through Markov procedure and proposed solution .The models set indicated that on basis of using the deta from two wells and five seis mic horizons, best result ,with 90% accuracy , is for reciprocatng motion. Manuscript profile

Open Access Article

6 - Propsing new approach for litho-facies modeling by use of Markov Chain method , an Iranian oil field
هانیه نیکو گفتار بهزاد تخم چی عباس بحرودی غلامحسین نوروزی

Reconnaissance and interpretation of underground heterogeneity, particularly litho-facies,always plays an important role in evaluation and management of hy dro carbon resources.between various methods presented for modeling discrete characteristics of More

Reconnaissance and interpretation of underground heterogeneity, particularly litho-facies,always plays an important role in evaluation and management of hy dro carbon resources.between various methods presented for modeling discrete characteristics of hydrocarbon reservoies such as litho-facies ,One with a more proper con formity with actual condition of reservoie facies is of great ad vantage . formed on basis of pro bability and presenting transition matrix, markov method is widely applied as a powerful tools for modeling the facies .In the present study , first the method is introduced in details; then, in order to optimize it, suggestion is made based on changing the type of the move of chain in simulation procedure. the case study is a 12 km long 110 m thick section of Anhydrite and three major members of asmari Formation from an oil field, South-West Iran.This section is modeed through Markov procedure and proposed solution .The models set indicated that on basis of using the deta from two wells and five seis mic horizons, best result ,with 90% accuracy , is for reciprocatng motion. Manuscript profile

Open Access Article

7 - Propsing new approach for litho-facies modeling by use of Markov Chain method , an Iranian oil field
هانیه نیکو گفتار عباس بحرودی بهزاد تخم چی غلامحسین نوروزی

Reconnaissance and interpretation of undeerground heterogeneity ,particularly litho-facies,always plays an important role in evaluation and management of hydrocarbon resources.Between various methods presented for modeling discrete characteristics of hydrocarb More

Reconnaissance and interpretation of undeerground heterogeneity ,particularly litho-facies,always plays an important role in evaluation and management of hydrocarbon resources.Between various methods presented for modeling discrete characteristics of hydrocarbon reservoirs such as litho-facies, one with a more proper conformity with actual condition of reservoir facies is of great advantage .Formed on basis of probability and presenting transition matrix.markov method is widely applied as a powerful tool for modeling the facies .In the present study ,first the method is introduced in details;then in order to optimize it. suggestion is made based on changing the type of the move of chain in simulation procedure. The case study is a12 km long 110 m thick section of Anhydrite and three major members of Asmari Formation from an oilfield ,south-West Iran .This section is modeled through Markov procedure and proposed solution.The models set indicated that on basis of using the data from two wells and five seismic horizons.best result ,with 90% accuracy, is for reciprocating motion. Manuscript profile

Open Access Article

8 - Cyclostratigraphy and Reservoir Correlation of the Oilgo-Miocene Sediments(Asmari Formation ) in the Marun Oilfield,Zagros Basin
شهرام آورجانی اسداله محبوبی حسن امیری بختیار

The Asmari Formation in the Marun Oilfield is composed of fossiliferous limestone, dolomitic limestone, argillaceous limestone,sandstone and shale. It is the major reservoir rock of Iran in several oil field of the Zagros Basin .The age of Asmari F More

The Asmari Formation in the Marun Oilfield is composed of fossiliferous limestone, dolomitic limestone, argillaceous limestone,sandstone and shale. It is the major reservoir rock of Iran in several oil field of the Zagros Basin .The age of Asmari Formation in this oilfield is oligo-Miocene(Rupelian-Burdigalian).In this study , subsurface correlation between the four wells in the Marun oilfield, based on climate stratigraphy is done by using Cyclolog Software.Nine positive and ten negative bounding surfaces have been identified .Some positive and negative bounding surfaces coincide with sequence boundaries and maximum flooding surface, respectively. In addition, some of the positive bounding surfaces identified the main time boundary (stage boundaries). Reservoir correlation between the ten compartments reservoir zones of the Asmari Formation in the Marun oilfield is done with these boundery surfaces.Some reservoir zones(especially the lower and middle Asmari reservroi zones) show perfect matching but others do not show the boundry of adaptive zones.It seems combining these data with other factors such as lithology ,porosity and permeability, detail revision of reservoir zoning of Asmari Formation Marun Oilfield is required. Manuscript profile

Open Access Article

9 - Biostratigraphy and Microfacies of the Asmari Formation in The Zagros Basin:Age and Environmental Correlation
تهمینه خانعلی

In this research ,biostratigraphy,microfacies and paleoenvionment of the Asmari Formation in the fars provingce(Tang-e Abolhayat,Naura anticline, south-west of Firozabad,Khormuj anticline),High Zagros(Shoorom anticline), IZeh zone (Mokhtar anticline),Dezfu More

In this research ,biostratigraphy,microfacies and paleoenvionment of the Asmari Formation in the fars provingce(Tang-e Abolhayat,Naura anticline, south-west of Firozabad,Khormuj anticline),High Zagros(Shoorom anticline), IZeh zone (Mokhtar anticline),Dezful Embayment(Tang-e Anbar sepid, Dill anticline, Khaviz anticline,Aghajari oil field ) and Lurstan province(Mamulan,Sepid-dasht,Dehluran and kabirkuh-Darreshahr0,were reviewed and revised for the comprehensive understanding of age and depositional environments. The Globigerina spp.-Turborotalia cerroazulensis-Hantkenina and Nummulites vascus-Nummulites fichteli assemblage zones (Rupelian) are present in Fars province. The dominated microfacies within the Asmari Formation of the Rupelian time are bioclast planktonic, nummulitidae lepidocyclinidae wackestone-packstone, of an outer and middle ramp depositional setting. The Archaias asmaricus-archaias hensoni-Miogypsinoides complanatus assemblage zone (Chattian)is present in Fars ,High zagros,Izeh and Dezful Embayment provinces. The dominated microfacies within the Asmari Formation of the Chattian time are bioclast perforate-imperforate foraminifera wackestone-packstone and mudstone, of an inner ramp depositional setting . The Miogypsina-Elphidium sp. 14-Peneroplis farsensis assemblage zone(Aquitanian) is present in High Zagros, Izeh ,Dezful Embayment and parts of the Fars and Lurestan provinces.The dominated microfacies within the Asmari Formation of the Aquitanian time are perforate-imperforate foraminifera bioclast wackestone –packstone,grainstone,and mudstone,of an inner ramp depositional setting. The Borelis melo curdica –Borelis melo melo assemblage zone (Burdigalian) is present in most areas. But it slightly occurs in fars province. The microfacies of the Asmari Formation during Burdigalian are similar to those of Aquitanian .In sepid-dasht and Tang-e Anbar Sepid sections due to presence Globigerina spp. Assemblage zone and planktonic forminifera wackestone-packstone facies, an outer ramp depositional setting is also suggested. Manuscript profile

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10 - Oligocene microfacies and sedimentary environment of the Asmari Formation at northwest of Deris village, west of Fars province: correlation with three other sections in Zagros Basin
samir Akhzari Ali Seyrafian

In this disquisition, Oligocene (Rupelian-Chattian) microfacies and sedimentary environment of the Asmari Formation at the northwest of Deris village, located in interior Fars zone of the Zagros Basin have been interpreted. The coordinates of such section are N: 29o 4 More

In this disquisition, Oligocene (Rupelian-Chattian) microfacies and sedimentary environment of the Asmari Formation at the northwest of Deris village, located in interior Fars zone of the Zagros Basin have been interpreted. The coordinates of such section are N: 29o 41' 59'', E: 51 o 32' 26''. The Asmari Formation deposits in this section are divided into 5 lithological units and consist of 460 m thin, medium, thick and massive bedded, gray and cream to gray limestone, slightly dolomitic with nodular and marly interbedded. By study of hyaline benthic foraminifera genera and non-foraminifera, and also recognition of some properties such as skeletal ingredient associations and sedimentary textures of thin sections, 14 microfacies have been introduced for the Asmari Formation. Gradual perpendicular changes of these microfacies represent that settling the Asmari Formation deposits took place in a homoclinal rapm. This homoclinal ramp consists of middle ramp and inner ramp, that are separated by shoal environment. Middle ramp is recognized by presence and dominition hyaline benthic foraminifera, coralline red algae and echinoids. The most significant skeletal debris of inner ramp are porcelainous foraminifera. To compare the thickness, age and sedimentary environment, zonal correlation of the Asmari Formation done in Deris section with three other sections (Naura anticline, Dill anticline and Dehloran) in the Zagros Basin. This correlation represent that the age of the Asmari Formation gets younger to the deeper parts of the foreland basin of the Zagros. Manuscript profile

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11 - Biostratigraphy, microfacies and sequence stratigraphy of the Asmari Formation (based on Cyclolog) in the Qaleh Nar Oli field, Zagros Basin
adel neisi ali Ghobeishav Mohammad Allahkarampour-Dill

In this research, biostratigraphy, microfacies, sedimentary environments and sequence stratigraphy (using by Cyclolog software) of the Asmari Formation are carried out. These studies are done on the basis of 580 samples (core and cutting) from 430 meters thickness of th More

In this research, biostratigraphy, microfacies, sedimentary environments and sequence stratigraphy (using by Cyclolog software) of the Asmari Formation are carried out. These studies are done on the basis of 580 samples (core and cutting) from 430 meters thickness of the formation from the well #2 of the Qaleh-Nar oilfield. Paleontological studies are led to identification of 23 genera and 28 species of the benthic and planktonic foraminifera. According to these microfossils, four assemblage zones have been recognized which confirm the age of Oligocene (Rupelian – Chattian) and Early Miocene (Aquitanian – Burdigalian) for the whole formation. Paleoenvironmental studies demonstrate 9 different microfacies that were deposited in the outer ramp (open marine) in the lower Asmari part, middle ramp (open marine to shoal) in the middle Asmari part and the inner ramp environment (tidal flat to lagoon) in the upper Asmari part. The sequence stratigraphy on the well #2 and the auxiliary well numbers 1, 3, 5, 6 and 7 of the Qaleh-Nar oilfield using by Cyclolog software reveals 7 positive breaks and 9 negative break levels alternatively. Some of the positive breaks define sequence boundaries and some of the negative breaks present the maximum flooding surfaces. In addition, a number of positive levels specify the major chronozone (stage boundaries). Comparison of the quintuple reservoir zones of the Asmari Formation in the Qaleh-Nar oilfield with the mentioned break levels suggests a fine correlation with these levels; however this correlation is invalid for other levels. Manuscript profile

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12 - Biostratigraphy and sedimentary environment of Asmari Formation in Davan section, North of Kazerun
masood khoshnood Hosyen Vaziri moghadam

This research concentrates on biostratigraphy, microfasies and Sedimentary environment of the Asmari Formation at Davan village in 10 Km north of Kazerun. Micropalaeontological study led to recognition of 25 genera and 15 species of foraminifera. Based on biostratigraph More

This research concentrates on biostratigraphy, microfasies and Sedimentary environment of the Asmari Formation at Davan village in 10 Km north of Kazerun. Micropalaeontological study led to recognition of 25 genera and 15 species of foraminifera. Based on biostratigraphic study 3 biozones (1-Nummulites vascus – Nummulites fichteli assemblage zone, 2 -Lepdocyclina-Operculina- Ditrupa Assemblage Zone, 3- Archaias asmaricus- Archaias hensoni- Miogypsinoides complanatus Assemblage Zone) are determined. As a result, the age of the Asmari Formation is Oligocene (Rupelian – Chattian) at the study area. Depositional texture, petrographic analyses and fauna led to identification of 9 carbonate microfacies related to open marine, slope, bar and lagoon. These depositional environments correspond to inner, middle, and outer ramp. Manuscript profile

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13 - Biostratigraphy and microfacies of the Asmari Formation in Lar anticline (northeast of Gachsaran): biostratigraphical correlation
Meysam Barari Kharkeshi Ali Seyrafian Hossein Vaziri-Moghaddam Roohollah Shabafrooz

The Asmari Formation at the Lar anticline, located 77 km northeast of Gachsaran city, comprised 361 meters in thickness. In the present study, biostratigraphy and microfacies of the Asmari Formation at the Lar anticline (northeast of Gachsaran city) is investigated. Bas More

The Asmari Formation at the Lar anticline, located 77 km northeast of Gachsaran city, comprised 361 meters in thickness. In the present study, biostratigraphy and microfacies of the Asmari Formation at the Lar anticline (northeast of Gachsaran city) is investigated. Based on foraminiferal distribution, 25 genera and 21 species have been identified and four biozones: 1. Lepidocyclina – Operculina – Ditrupa assemblage zone, 2. Archaias asmaricus – Archaias hensoni – Miogypsinoides complanatus assemblage zone, 3. Indeterminate zone, 4. Borelis melo curdica – Borelis melo melo assemblage zone, representing Oligocene (Chattian) to Early Miocene (Aquitanian - Burdigalian) are introduced, respectively. 12 microfacies related to an open marine and lagoon (semi-closed and closed) environments of homoclinal ramp setting are present. Manuscript profile

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14 - Biostratigraphy and microfacies of the Asmari Formation in north flank of Khami anticline (north of Gachsaran)
Mona Rahim Abadi Hossein Vaziri-Moghaddam Ali Seyrafian farzad Sotohian

In the present study, biostratigraphy, microfacies and sedimentary environment of the Asmari Formation in north flank of the Khami anticline in the north of the Gachsaran province is investigated. The Asmari Formation at the study section with a thickness of 276 meters More

In the present study, biostratigraphy, microfacies and sedimentary environment of the Asmari Formation in north flank of the Khami anticline in the north of the Gachsaran province is investigated. The Asmari Formation at the study section with a thickness of 276 meters is a thin, medium and thick to massive limestone, nodular limestone, marl, marly limestone, dolomite and dolomitic limestone. In this study 166 thin sections are studied and 23 genera and 24 species of foraminifera have been identified and 3 biozones are introduced. 1- Archaias asmaricus-Archaias hensoni-Miogypsinoides complanatus Assemblage zone. (Chattian) 2- Indeterminate zone (Aqutanian) 3- Borelis melo curdica-Borelis melo melo Assemblage zone. (Burdigalian) Thus, the age of the Asmari Formation at the study area is Chattian to Burdigalian (Oligo-Miocene). Based on study of thin sections and by considering the sediment texture, distribution of skeletal and non-skeletal grains, 12 microfacies are recognized which were deposited in open marine, bar, semi-restricted and restricted lagoon. Four platform types for the Asmari Formation at the study area in comparison with the recent studies on Asmari Formation including: 1-Rupelian-lower Chattian: Distally steepend ramp, 2-middle Chattian-upper Chattian: open shelf, 3-Aqiutanian: homoclinal ramp, 4-lower Burdigalian: carbonate platform. Manuscript profile

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15 - The impact of microfacies and diagenesis characteristics on the reservoir quality of Asmari Formation in the Gevarzin gas field, Zagros basin, south Iran
Karim Mombani Ahmad Yahyaei

Asmari Formation from the Gavarzin gas field have erosional unconformity boundary on marl and pelagic limestones of Pabdeh Formation and gradually change to evaporate cap rock of Gachsaran Formation. Cores studies from the one of wells of Gavarzin field is 183 m in thic More

Asmari Formation from the Gavarzin gas field have erosional unconformity boundary on marl and pelagic limestones of Pabdeh Formation and gradually change to evaporate cap rock of Gachsaran Formation. Cores studies from the one of wells of Gavarzin field is 183 m in thickness, which includes 1.30 m from the top of Pabdeh, 162.4 m from the Asmari Formation and 19.30 m from the base layers of Gachsaran. Asmari Formation includes alternation of limestone, calcite dolomitic, claystone and shale with green marl. Petrology and facies analysis of the sequence of these formations identified 12 microfacies, a carbonate ramp from deep-sea to sabkha environments and formed in a retrograded sequence. This ramp includes deep environments, open sea, patch reef, bio-, clastic-bars, lagoon and tidal environments, which confirms a changing environment due to rapid facies changes and deposition of evaporative sediments in Gachsaran as a restricted environment. Diagenesis processes are considered as the main factors in carbonate reservoir quality of Gavarzin field. The diagenesis history of the Asmari carbonates of the studied cores is summarized as A) marine phreatic diagenesis, bioturbation, micritization and cementation processes occurred. B) vadose zone diagenesis, where the crystallization, cementation, and dissolution occurred. C) burial diagenesis, comprises compression-induced, pressure dissolution and fracturing are common. The microfacies show a wide varieties of reservoir characteristics and therefore a heterogeneous reservoir has been formed. Micro-fractures, however have strongly influence on the reservoir quality in the section. The simultaneous presence of dissolved spaces and fractures in the reservoir the permeability greatly increased. The best reservoir quality in the Grainstone/Packston facies are coated grains with moldic porosity that were created by the leaching of Ooid-bearing Packston lithology during the diagenesis of atmospheric waters. Manuscript profile

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16 - (Biostratigraphy and microfacies of the Asmari Formation in south flank of Mish anticline (northeast of Gachsaran
Saber Ahmadi Ali seyrafian Hosyen vaziri-Moghadam

Asmari Formation at the section of the south flank of Mish anticline (northeast of Gachsaran), located 22 km northeast of Basht city, in vicinity village Kalagh ¬Neshin is investigated and has a thickness of 281 meters. In this research, biostratigraphy and microfacies More

Asmari Formation at the section of the south flank of Mish anticline (northeast of Gachsaran), located 22 km northeast of Basht city, in vicinity village Kalagh ¬Neshin is investigated and has a thickness of 281 meters. In this research, biostratigraphy and microfacies of the Asmari Formation in this section were studied and the results were compared with 5 section of Asmari Formation in similar regions and close to it. By studying on 172 microscopic sections, 3 the biozone for Asmari Formation in the section the study was carried out and the section studied given that is: Lepidocyclina – Operculina – Ditrupa assemblage zone. Archaias asmaricus – Archaias hensoni – Miogypsinoides complanatus assemblage zone. Indeterminate zone. According to the study of benthic foraminifera and biozones, the cut off age is from the late Oligocene (Rupelian-Chattian) to the early Miocene (Aquitanian). Microfacies studies led to identify 10 microfacies and 4 subfacial belonging to the open marine and lagoon (semi-closed and enclosed) environments, which includes the external, intermediate, and interior parts of a hemocalinal ramp. Manuscript profile

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17 - Isotopic and Geochemical comparison of Bangestan and Asmari Oils to determine origination
ashkan Zardashti Morteza Tabaei mahmood memariani

In order to analyze the geochemical characteristics, the oil samples of the Asmari reservoirs and the Bangistan group in the Kopal field were studied using various geochemical techniques such as asphalting technique, gas chromatography technique, gas chromatography-mass More

In order to analyze the geochemical characteristics, the oil samples of the Asmari reservoirs and the Bangistan group in the Kopal field were studied using various geochemical techniques such as asphalting technique, gas chromatography technique, gas chromatography-mass spectrometry technique and carbon isotope measurement technique, were subjected to analysis. the purpose of This research is a comparison of carbon isotope and geochemical properties of Asmara and Bangestan oils in Kopal field to determine their parent rock and origin. Considering the results of the testing technique and analysis of biomakers of the esteranes and terpanes family extracted from saturated cutting, it can be stated that the oils accumulated in the Asmari and Bangestan reservoirs of the Kopal field have the characteristics of oil. are paraffinic, which indicates the existence of light oil with good quality, mature, low viscosity and high sulfur. By placing the ratio of biomarker parameters against carbon 13 isotope and examining the general results of the graphs, it was found that the oil samples of Asmari reservoirs and Bangestan reservoirs in the studied field are from a common generative rock. have been found and have the same characteristics and only slightly differ in maturity, degree of fluidity, and the amount of migration processes between the source rock and the reservoir rock, and similarly, the transformation course of the source rock organic materials has occurred naturally in the Copal field. The values of carbon isotopes in the oils indicate the average maturity of the rocks producing the oils. The graph of the ratio of the aromatic carbon 13 isotope against the saturated carbon 13 isotope showed that both field oil samples The subject of study belongs to marine environments. Manuscript profile

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18 - The history of deposition and post-deposition and their effects on the reservoir quality of Asmari Formation in Ahvaz oilfield
Akbar Heidari Milad Faraji Narges Shokri

The carbonate interval of the Asmari formation along with sandstone deposits were deposited in most areas of the Zagros sedimentary Basin, including the Ahvaz area, in Oligo-Miocene. In this study, the effects of depositional and post-depositional environments on the re More

The carbonate interval of the Asmari formation along with sandstone deposits were deposited in most areas of the Zagros sedimentary Basin, including the Ahvaz area, in Oligo-Miocene. In this study, the effects of depositional and post-depositional environments on the reservoir quality of zone A7 of the Asmari Formation in well No. 4 in Ahvaz oil field were studied. The study of the sequences of the Asmari Formation in this section led to the identification of 11 carbonate facies, one evaporite facies, one mixed carbonate-siliciclastic facies, and one siliciclastic facies. Sedimentary environments of tidal zone, lagoon, coral reef and open sea were introduced for the depositional environment of identified facies. Due to the absence of sudden changes, it seems that the studied deposits were deposited in a ramp-type carbonate platform that was influenced by siliciclastic sediments from the Zagros river systems. The immature sedimentary texture of the sandstone facies indicates the proximity of the origin of the quartz sources to the carbonate basin. Among the diagenetic processes that have affected the examined sequences, the following processes can be mentioned: micritization, cementation, neomorphism, physical and chemical compaction, dissolution, fracture development and filling, dolomitization, and anhydritization. These diagenetic processes occurred in post-depositional marine, meteoric and burial diagenetic environments. Many fractures were filled with petroleum, which indicates that fractures, along with dolomitization, chemical compaction, and fenestral pores, are among the most important post-sedimentation complications to increase reservoir quality. While cementation and anhydritization resulted in reducing the reservoir quality by closing the pore spaces . Manuscript profile

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19 - Reconstruction of Asmari Formation Sedimentary Environment in Asmari and Gurpi Anticlines in the oil field of Masjed Soleiman (Southwest of Iran)
Navab Varnaseri Davood Jahani Nader Kohansal Ghadimvand Mohsen Pourkermani

In this research, the process of lithological changes and diagenetic processes of Asmari formation with Oligo-Miocene age has been investigated. For this purpose, 400 samples were selected and collected from a section of the Masjid Suleiman oil field and the surface sec More

In this research, the process of lithological changes and diagenetic processes of Asmari formation with Oligo-Miocene age has been investigated. For this purpose, 400 samples were selected and collected from a section of the Masjid Suleiman oil field and the surface section of the Asmari anticline in the Dezful depression and the Gurpi anticline in the Izeh zone. Petrographic studies revealed 18 sedimentary microfacies that were deposited on a ramp-type carbonate platform. Among the significant diagenetic processes in the region are the process of micritization, bioturbation and the influence of burrowing organisms, cementation (types of cement related to marine, meteoric and burial diagenesis environments), dissolution (meteoric and burial dissolution), dolomitization (in different phases), silicification, pyritization, phosphatization, mechanical compaction, chemical compaction, fracture and porosity. Based on the identification of the sequence boundaries and following the facies depth changes, the carbonate sequence of the Asmari formation in the subsurface section and the Asmari anticline section are introduced in the form of 3 sedimentary sequences of the third order shallowing upwards, which are the former Aquitanian, the late Aquitanian and Bordigalin belong. Among the dominant porosities in the Asmari Formation, we can mention the hole, mold and fracture porosities. Manuscript profile

Open Access Article

20 - Stratigraphy, facies and depositional conditions of the Asmari Formation (Rupelian-Burdigalian) in the south-eastern folded Zagros, Bandarlengeh embayment (Khamir salt mountain section)
Peyman Rezaei Seyedeh Akram Jooybari Abdullah Najafi

Asmari Formation (Rupelian-Burdigalian) is one of the most well-known formations in Iran. In order to investigate the stratigraphy and sedimentary environment, a section of this formation was selected in Khamir salt mountain section in Bandarlengeh embayment. In this nu More

Asmari Formation (Rupelian-Burdigalian) is one of the most well-known formations in Iran. In order to investigate the stratigraphy and sedimentary environment, a section of this formation was selected in Khamir salt mountain section in Bandarlengeh embayment. In this number, 70 limestone microscopic thin sections and 3 marl samples (XRF) were evaluated to identify the microfacies and the sedimentation conditions.The petrographic study led to the identification of 10 microfacies belonging to the facies belts of tidal, lagoon, carbonate bar, open marine, which were deposited in the homoclinal carbonate ramp environment. The composition of marl facies oxides also indicates the presence of carbonate minerals, quartz and clay minerals, which along with field observations and alternating calcareous facies suggest that this facies was deposited in an open marine environment. Finally, it seems that the facies and fossil diversity of the Asmari Formation in the mentioned section is such that during the Aquitanian stage, this formation was located closer to the coast line and during the Rupelian and Chattian-Burdigalian times, it was located at a further distance from the coast line. Manuscript profile

Open Access Article

21 - Reservoir quality evaluation of the Asmari Formation in the framework of sequence stratigraphy in one of the Iranian SW oilfield
Ebrahim Sfidari A. Hakymi-Zanuz

The Oligo-Miocene Asmari Formation forms the main reservoir rock of many Dezful Embayment fields. Microfacies analysis, diagenetic features, and sequence stratigraphic evaluation of the Asmari Formation were carried out based on the petrographic investigation, petrophys More

The Oligo-Miocene Asmari Formation forms the main reservoir rock of many Dezful Embayment fields. Microfacies analysis, diagenetic features, and sequence stratigraphic evaluation of the Asmari Formation were carried out based on the petrographic investigation, petrophysical logs, and core measurement porosity and permeability data. Petrographic analyses led to the identification of twelve microfacies indicating five subenvironments including tidal flat, lagoon, barrier (belonging to inner ramp), middle ramp, and outer ramp, all of which are representing a homoclinal ramp. Tidal flat, lagoonal, and barrier microfacies are mostly present in the upper parts of the Asmari Formation, while middle and outer ramp microfacies were largely developed in the middle part. Cementation, compaction, dolomitization, dissolution, and fracturing are the main diagenetic processes in this formation. Compaction and cementation have negatively affected reservoir quality while fracturing, dolomitization, and dissolution contributed to reservoir quality enhancement. The sequence stratigraphic studies represent three 3rd order sequences of early Aquitanian, late Aquitanian, and early Burdigalian age based on the main features of microfaces, their depositional environments, and shallowing and deepening-upward trends. Microfacies of the Transgressive System Tract (TST) have been affected by compaction, dissolution (moldic), cementation, and slightly dolomitization in the middle to outer ramp parts. The Highstand System Tract in the inner ramp part has been affected by dolomitization, dissolution, and fracturing close to the sequence boundaries, and has a better reservoir quality than the Transgressive System Tract. Manuscript profile

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