The upstream water catchments are the main source providing sediments in rivers and sedimentary basins. The balance between the erosion phenomenon and the amount of sediment entering into the basin relies on the geome...The upstream water catchments are the main source providing sediments in rivers and sedimentary basins. The balance between the erosion phenomenon and the amount of sediment entering into the basin relies on the geometrical specifications and the morphology of the river along the water catchment direction and the amount and type of the sediments. The sedimentary feed of rivers and basins are changed for the sake of natural factors or human disturbances. The river and basin react against this change in that their shape, morphology, plan and profile get changed due to the increase or decrease of the input sediment into the basin. It is essential to know the sediment amount produced by erodability and sedimentation of upstream basins and effects of projects and also to evaluate the amount of sedimentary load in base studies, civil projects, optimizing rivers and dam construction studies specially calculating the amount of sediment amount entering into the dams’ reservoirs in order to take engineering decisions and related alternatives. Sediment Weight Model and PSIAC Experimental Model are recognized as two common methods calculating the amount of the produced sediment caused by erosion applied in this research. Holistically, these methods have been used and compared. Although the results are almost close to one another, more sediment load has been produced in PSIAC method. As more affective parameters are used to cause erosion and produce sediment in PSIAC experimental model, it is recommended to refer to the results of this method because they are closer to reality.展开更多
In this study, to identify and analyze facies of depositional environment and depositional model of Qom Formation, stratigraphic Saran Section (southwest of Semnan) was selected. Qom Formation in Saran section include...In this study, to identify and analyze facies of depositional environment and depositional model of Qom Formation, stratigraphic Saran Section (southwest of Semnan) was selected. Qom Formation in Saran section includes about 380 meters of conglomerate at the base, chalk, limestone, marl, and shale. Petrographic studies with facies analysis have led to the identification of 12 microfacies, these microfacies have been deposited in four facies groups including tidal flat, lagoon, barrier and open marine. Study of horizontal and vertical facies changes and their comparison with recent and ancient environments reveals that Qom Formation in this section relates to shallow marine environment and its facies were deposited in a shelf carbonate platform and are comparable with contemporary shelf platforms such as Florida and old shelf platforms such as Mozduran. The most important diagenetic processes affecting the studied section include micritization, bioturbation, cementation, dissolution, neomorphism, fracturing, mechanical and chemical compaction, hematitization and dolomitization. These processes have formed in marine, meteoric and burial diagenetic environments.展开更多
As sediments are produced and accumulated in sedimentary basins especially in dams’ reservoirs and they highly affect the reservoirs life span, it is essential to scrutinize the effect of lithology and types of geolo...As sediments are produced and accumulated in sedimentary basins especially in dams’ reservoirs and they highly affect the reservoirs life span, it is essential to scrutinize the effect of lithology and types of geological formations of an area on the life span of reservoirs specifically from the viewpoints of the erodability of these formations due to their lithology type. Lali area, Khuzestan, Iran and the water catchment of the intended area (based on geological situation and Taraz dam situation) are placed in the sedimentary-structural zone of the folded Zagros. The method of this research is based on analyzing the topography and geology maps and field work in order to identify the lithology of the geological formations. In fact, the amount of its erodability has been characterized by the type of the geological formations. The current research aims at putting the geological results, lithological data of the formations types and the outcrop of the soil-lithological units together in order to evaluate the sedimentary and erosive factors of these units and precisely identify the area’s geological formations to remove the ambiguities in this issue. Studies indicate that formations made of looser gypsum and marl like Pabde-Gurpi and Gachsaran are exposed to more sedimentation and erosion than the formations made of compacted lime stone and conglomerate with silica-lime cement such as Bakhtiary and Asmari formations and the sand stones of Aghajari formation reveal the moderate to high resistance. Thus, the lithological identification of the formations, the type of sediments and their looseness and hardness contribute to detect the amount and type of deposits entering into the dam reservoir. The type and amount of these transported and deposited sediments are assessed to predict more suitable optimized ways to exploit dams’ reservoirs.展开更多
PSIAC empirical method is considered as one of the methods calculating and estimating the amount of erodibility and sedimentation of sedimentary deposits in sedimentary basins and dams’ reservoirs. This method is bas...PSIAC empirical method is considered as one of the methods calculating and estimating the amount of erodibility and sedimentation of sedimentary deposits in sedimentary basins and dams’ reservoirs. This method is based on analyzing nine influential factors including: surface geology, solid, weather, runoff, unpaved area, limited plant coverage, land usage, high lands erosion, river erosion and sediment transportation. These factors are rated according to their level of importance. The case study of this research is Lali Water Catchment, Khuzestan, Iran. The amount and intensity of adorability will be ranked as low, moderate and high. This research is based on field work, laboratorial studies and analyzing results obtained from statistics. Results indicated that the unpaved area and high land erosion are identified as the most effective factors, respectively. In contrast, runoff and surface geology are considered as the lowest rate. Other factors reflect moderate effects. Since any significant studies have not been done in this regard, the current research can present a new method to scrutinize the empirical effects of these factors. It is noteworthy to highlight that different methods are compared with each other in order to scrutinize the amount of erodibility in most studies, but the present study has analyzed the influential factors of the sub-methods of one major method. This essay focuses on the affectability of each one of the nine factors, independently. In conclusion, the outcomes of this research can contribute to identify and determine suitable alternatives to stabilize sedimentary basins and increase the life span of dams and watershed management projects and also reduce the destructive effects of floods. Additionally, it contributes civil projects in such lands.展开更多
The Sarvak Formation is the second major oil-bearing reservoir in the south and south west of Iran. The Middle Cretaceous Sarvak formation in the Zagros Mountains (Zagros Basin) is mainly composed of carbonate sequenc...The Sarvak Formation is the second major oil-bearing reservoir in the south and south west of Iran. The Middle Cretaceous Sarvak formation in the Zagros Mountains (Zagros Basin) is mainly composed of carbonate sequences. Based on facies studied, thirteen microfacies were recognized in the studied area, which were categorized in the three facies groups: including inner ramp, mid ramp and outer ramp. Evidences such as the gradual changes in the facies (basin slope), the absence of extensive uninterrupted barrier reef, the lack of calciturbidite and gravity sediments as well as the high proportion of grain-supported indicated that the Sarvak Formation was deposited in the ramp like depositional system, particularly on an inner ramp setting. Inner ramp facies group is the principal setting and subdivided to tidal flat, restricted and unrestricted lagoon as well as shoal sub-environments.展开更多
The study area is located in the Fars area (Interior Fars sub-basin). This area, which is part of the Zagros fold-thrust belt, is located in Zagros simple folded sub zone. It is known as one of the most important regi...The study area is located in the Fars area (Interior Fars sub-basin). This area, which is part of the Zagros fold-thrust belt, is located in Zagros simple folded sub zone. It is known as one of the most important regions in the world Gas rich. In this area, anticlinal folds are a different orientation of such as the North Western-South Eastern, East-West and North Eastern-South Western. The Karbasi and Khaftar anticlines are case study anticlines in the interior Fars sub-basin (Fassa area). The anticlines in the Fars region, which are located in the Zagros fold-thrust belt, are valuable because they possess several hydrocarbons. The main aim of this paper is evaluation of hydrocarbon potential in the Jahrom area (Interior Fars) based on interpretation of the Isopach maps and well data. This paper presents part of the results of a regional study of the Coastal Fars area in the Zagros Simply folded belt, based on original fieldwork, satellite images, structural sections, geological maps and well data. In order to investigate of periods Nezamabad fault activity, Isopach maps of the study area has been prepared based on well drilling data and the thickness of the drilled formations. In this study utilizes the thickness of the drilled formations in the study area, for each sedimentary unit was carried out to prepare Isopach maps. The Isopach map prepared based on GIS software method and exploration well data. The Nezamabad fault has been lacked of activity at the deposition time of the Dalan, Kangan, Dashtak, Fahliyan, Gadvan, Dariyan, Kazhdomi, Sarvak, Gurpi and Pabdeh formations within the Khaftar and Karbasi anticline area. Accordingly, changes in basin floor, at the time of sedimentation these formations has not been affected by the Nezamabad fault. Probably the Nezamabad fault has been activated during deposition of the Surmeh, Hith, Laffan and Ilam formations and in this area paleo-basin has been controlled by this fault. In other words, it seems that, activity of the Nezamabad fault in this area have been limited to Jurassic and Cretaceous periods (Coniacian and Senomanian). This can means that in this periods time, the Nezamabad fault have been active sedimentation along with tectonic processes and activities affected on thickness of the Surmeh, Hith, Laffan and Ilam formations. Finally, it seems that the Nezamabad Fault activity has been affected on the source rock, reservoir rock and cap rock and then controlled distributing of hydrocarbon System of the study area in the Khaftar and Karbasi as anticlinal oil traps.展开更多
The Upper Cretaceous carbonate successions of the Sarvak Formation host giant oil reservoirs in the Persian Gulf.In this research,a total of 28 oil samples from nine oilfields located in the western,central and easter...The Upper Cretaceous carbonate successions of the Sarvak Formation host giant oil reservoirs in the Persian Gulf.In this research,a total of 28 oil samples from nine oilfields located in the western,central and eastern parts of the Persian Gulf region were studied to determine the genetic relationships of oils,depositional setting of possible source rocks,thermal maturity,and source-rock ages in the Persian Gulf basin.According to the measured geochemical data,the source rocks facies vary from marine carbonates and marl/carbonates in the central and eastern oilfields to shale/carbonates in the western oilfields.The Pr/Ph ratio,steranes and terpanes suggest anoxic to dysoxic conditions of the depositional environments.The depositional environments experienced both low water stratification/low salinity and normal salinity/unstratified conditions.Evaluation of the saturated and aromatic biomarkers shows that all oil samples are mature and most of the source rocks lie within the beginning of the oil-generation window.The thermal maturity of the central oilfields is higher than that of the other samples,and has gone beyond the oil-generation stage.The C2s/C2g steranes ratio suggest that the central oilfelds of the Persian Gulf have Paleozoic and Jurassic source rocks,whereas the Sarvak reservoir in other parts of this region is sourced from Cretaceous carbonate rocks.展开更多
文摘The upstream water catchments are the main source providing sediments in rivers and sedimentary basins. The balance between the erosion phenomenon and the amount of sediment entering into the basin relies on the geometrical specifications and the morphology of the river along the water catchment direction and the amount and type of the sediments. The sedimentary feed of rivers and basins are changed for the sake of natural factors or human disturbances. The river and basin react against this change in that their shape, morphology, plan and profile get changed due to the increase or decrease of the input sediment into the basin. It is essential to know the sediment amount produced by erodability and sedimentation of upstream basins and effects of projects and also to evaluate the amount of sedimentary load in base studies, civil projects, optimizing rivers and dam construction studies specially calculating the amount of sediment amount entering into the dams’ reservoirs in order to take engineering decisions and related alternatives. Sediment Weight Model and PSIAC Experimental Model are recognized as two common methods calculating the amount of the produced sediment caused by erosion applied in this research. Holistically, these methods have been used and compared. Although the results are almost close to one another, more sediment load has been produced in PSIAC method. As more affective parameters are used to cause erosion and produce sediment in PSIAC experimental model, it is recommended to refer to the results of this method because they are closer to reality.
文摘In this study, to identify and analyze facies of depositional environment and depositional model of Qom Formation, stratigraphic Saran Section (southwest of Semnan) was selected. Qom Formation in Saran section includes about 380 meters of conglomerate at the base, chalk, limestone, marl, and shale. Petrographic studies with facies analysis have led to the identification of 12 microfacies, these microfacies have been deposited in four facies groups including tidal flat, lagoon, barrier and open marine. Study of horizontal and vertical facies changes and their comparison with recent and ancient environments reveals that Qom Formation in this section relates to shallow marine environment and its facies were deposited in a shelf carbonate platform and are comparable with contemporary shelf platforms such as Florida and old shelf platforms such as Mozduran. The most important diagenetic processes affecting the studied section include micritization, bioturbation, cementation, dissolution, neomorphism, fracturing, mechanical and chemical compaction, hematitization and dolomitization. These processes have formed in marine, meteoric and burial diagenetic environments.
文摘As sediments are produced and accumulated in sedimentary basins especially in dams’ reservoirs and they highly affect the reservoirs life span, it is essential to scrutinize the effect of lithology and types of geological formations of an area on the life span of reservoirs specifically from the viewpoints of the erodability of these formations due to their lithology type. Lali area, Khuzestan, Iran and the water catchment of the intended area (based on geological situation and Taraz dam situation) are placed in the sedimentary-structural zone of the folded Zagros. The method of this research is based on analyzing the topography and geology maps and field work in order to identify the lithology of the geological formations. In fact, the amount of its erodability has been characterized by the type of the geological formations. The current research aims at putting the geological results, lithological data of the formations types and the outcrop of the soil-lithological units together in order to evaluate the sedimentary and erosive factors of these units and precisely identify the area’s geological formations to remove the ambiguities in this issue. Studies indicate that formations made of looser gypsum and marl like Pabde-Gurpi and Gachsaran are exposed to more sedimentation and erosion than the formations made of compacted lime stone and conglomerate with silica-lime cement such as Bakhtiary and Asmari formations and the sand stones of Aghajari formation reveal the moderate to high resistance. Thus, the lithological identification of the formations, the type of sediments and their looseness and hardness contribute to detect the amount and type of deposits entering into the dam reservoir. The type and amount of these transported and deposited sediments are assessed to predict more suitable optimized ways to exploit dams’ reservoirs.
文摘PSIAC empirical method is considered as one of the methods calculating and estimating the amount of erodibility and sedimentation of sedimentary deposits in sedimentary basins and dams’ reservoirs. This method is based on analyzing nine influential factors including: surface geology, solid, weather, runoff, unpaved area, limited plant coverage, land usage, high lands erosion, river erosion and sediment transportation. These factors are rated according to their level of importance. The case study of this research is Lali Water Catchment, Khuzestan, Iran. The amount and intensity of adorability will be ranked as low, moderate and high. This research is based on field work, laboratorial studies and analyzing results obtained from statistics. Results indicated that the unpaved area and high land erosion are identified as the most effective factors, respectively. In contrast, runoff and surface geology are considered as the lowest rate. Other factors reflect moderate effects. Since any significant studies have not been done in this regard, the current research can present a new method to scrutinize the empirical effects of these factors. It is noteworthy to highlight that different methods are compared with each other in order to scrutinize the amount of erodibility in most studies, but the present study has analyzed the influential factors of the sub-methods of one major method. This essay focuses on the affectability of each one of the nine factors, independently. In conclusion, the outcomes of this research can contribute to identify and determine suitable alternatives to stabilize sedimentary basins and increase the life span of dams and watershed management projects and also reduce the destructive effects of floods. Additionally, it contributes civil projects in such lands.
文摘The Sarvak Formation is the second major oil-bearing reservoir in the south and south west of Iran. The Middle Cretaceous Sarvak formation in the Zagros Mountains (Zagros Basin) is mainly composed of carbonate sequences. Based on facies studied, thirteen microfacies were recognized in the studied area, which were categorized in the three facies groups: including inner ramp, mid ramp and outer ramp. Evidences such as the gradual changes in the facies (basin slope), the absence of extensive uninterrupted barrier reef, the lack of calciturbidite and gravity sediments as well as the high proportion of grain-supported indicated that the Sarvak Formation was deposited in the ramp like depositional system, particularly on an inner ramp setting. Inner ramp facies group is the principal setting and subdivided to tidal flat, restricted and unrestricted lagoon as well as shoal sub-environments.
文摘The study area is located in the Fars area (Interior Fars sub-basin). This area, which is part of the Zagros fold-thrust belt, is located in Zagros simple folded sub zone. It is known as one of the most important regions in the world Gas rich. In this area, anticlinal folds are a different orientation of such as the North Western-South Eastern, East-West and North Eastern-South Western. The Karbasi and Khaftar anticlines are case study anticlines in the interior Fars sub-basin (Fassa area). The anticlines in the Fars region, which are located in the Zagros fold-thrust belt, are valuable because they possess several hydrocarbons. The main aim of this paper is evaluation of hydrocarbon potential in the Jahrom area (Interior Fars) based on interpretation of the Isopach maps and well data. This paper presents part of the results of a regional study of the Coastal Fars area in the Zagros Simply folded belt, based on original fieldwork, satellite images, structural sections, geological maps and well data. In order to investigate of periods Nezamabad fault activity, Isopach maps of the study area has been prepared based on well drilling data and the thickness of the drilled formations. In this study utilizes the thickness of the drilled formations in the study area, for each sedimentary unit was carried out to prepare Isopach maps. The Isopach map prepared based on GIS software method and exploration well data. The Nezamabad fault has been lacked of activity at the deposition time of the Dalan, Kangan, Dashtak, Fahliyan, Gadvan, Dariyan, Kazhdomi, Sarvak, Gurpi and Pabdeh formations within the Khaftar and Karbasi anticline area. Accordingly, changes in basin floor, at the time of sedimentation these formations has not been affected by the Nezamabad fault. Probably the Nezamabad fault has been activated during deposition of the Surmeh, Hith, Laffan and Ilam formations and in this area paleo-basin has been controlled by this fault. In other words, it seems that, activity of the Nezamabad fault in this area have been limited to Jurassic and Cretaceous periods (Coniacian and Senomanian). This can means that in this periods time, the Nezamabad fault have been active sedimentation along with tectonic processes and activities affected on thickness of the Surmeh, Hith, Laffan and Ilam formations. Finally, it seems that the Nezamabad Fault activity has been affected on the source rock, reservoir rock and cap rock and then controlled distributing of hydrocarbon System of the study area in the Khaftar and Karbasi as anticlinal oil traps.
文摘The Upper Cretaceous carbonate successions of the Sarvak Formation host giant oil reservoirs in the Persian Gulf.In this research,a total of 28 oil samples from nine oilfields located in the western,central and eastern parts of the Persian Gulf region were studied to determine the genetic relationships of oils,depositional setting of possible source rocks,thermal maturity,and source-rock ages in the Persian Gulf basin.According to the measured geochemical data,the source rocks facies vary from marine carbonates and marl/carbonates in the central and eastern oilfields to shale/carbonates in the western oilfields.The Pr/Ph ratio,steranes and terpanes suggest anoxic to dysoxic conditions of the depositional environments.The depositional environments experienced both low water stratification/low salinity and normal salinity/unstratified conditions.Evaluation of the saturated and aromatic biomarkers shows that all oil samples are mature and most of the source rocks lie within the beginning of the oil-generation window.The thermal maturity of the central oilfields is higher than that of the other samples,and has gone beyond the oil-generation stage.The C2s/C2g steranes ratio suggest that the central oilfelds of the Persian Gulf have Paleozoic and Jurassic source rocks,whereas the Sarvak reservoir in other parts of this region is sourced from Cretaceous carbonate rocks.
