• List of Articles گچ

      • Open Access Article

        1 - Geochemistry, microfacies and depositional environment of Eocene Deposit in Gach Mountain, in SE Lar Area
        محمد حسين  آدابي
        The Jahrum Formation in Gach Mountain, located near village of Chahar Berkeh, in 30 Km of south- east of Lar City, south- west of Iran (Zagros Basin). This formation with the total thickness of 404.5 m consists of dolomite, calcareous dolomite and limestone. This form More
        The Jahrum Formation in Gach Mountain, located near village of Chahar Berkeh, in 30 Km of south- east of Lar City, south- west of Iran (Zagros Basin). This formation with the total thickness of 404.5 m consists of dolomite, calcareous dolomite and limestone. This formation overlies the Sachun Formation. The Asmari Formation with the total thickness of 44.5 m consists of limestone and marly limestone, and covered by evaporite deposits of the Gachsaran Formation. The age of the Jahrum Formation is Late Paleocene to Late Eocene. Eocene deposit in Gach Mountain, based on different facies, foraminifera and other skeletal and non skeletal grains, 7 microfacies were recognized. These microfacies deposited in a carbonates ramp environment with ooid shoal deposits. Analysis of 30 samples of limestones and dolomites for major and minor elements (Ca, Mg, Fe, Mn, Na, and Sr) and oxygen and carbon isotope values were used for carbonate mineralogy, types of dolomites, and diagenetic system. This study indicates that Jahrum carbonates were deposited in a shallow warm water tropical environment and original carbonate mineralogy was aragonite. These carbonates were affected by close to semi close diagenetic system with low water/rock interaction. Diagenetic trend in limestones and dolomite, based on oxygen and carbon isotope variations, shows a burial diagenesis with the presence of origanic matter. Temperature calculation based on heaviest oxygen isotope values (-3.32% PDB) of micrite and δw of Eocene seawater of - 0.85 SMOW, indicate that very shallow burial temperature was around 23˚C. Sequence stratigraphic studies, shows that two depositional sequences, consisting of transgrassive system tract (TST) and highstand system tract (HST). This sequences, shows third order type, with sequence boundaries (SB2). Maximum flooding surface in the Jahrum Formation was determined based on different facies and variation of isotope values. Manuscript profile
      • Open Access Article

        2 - The hydrogeological water balance of Barm-e-Shour wetland in the Haftkel city, Khuzestan province
        Farzad Akbari rahim bagheri Arash Nadri
        Wetlands are the most important and yet vulnerable environmental resources which are vital as water resources to agriculture, springs, ground water recharge and ecology. Therefore, the management and restoration of the wetlands are of great importance and require hydrog More
        Wetlands are the most important and yet vulnerable environmental resources which are vital as water resources to agriculture, springs, ground water recharge and ecology. Therefore, the management and restoration of the wetlands are of great importance and require hydrogeological scrutiny. Barm-e-Shour is one of the most important wetlands in Khuzestan province and is utilized for drinking and agricultural purposes. The wetland is situated on Gachsaran evaporate formation. There are no permanent surface inflows, yet the wetland maintains a steady reservoir, despite the recent drought and water supply limitations. Water and recharge origin which require calculating hydrogeological balance have not been studied so far. To achieve this goal, the iso-depth map, annual water level fluctuation, catchment area and different parameters of water balance were determined. The maximum depth during the dry season was about 3 meters. According to hydrogeological surveys the water balance was positive so that the yearly inflow of water was about 10912 m3 indicating the main role of ground water in wetland recharge. Considering the karst development and isotopic results, carbonates of the Asmari anticline is the most probable source of Barm-e-Shour wetland water. Manuscript profile
      • Open Access Article

        3 - The effect of the Gachsaran mobile formation on folding style and tectonic evolution of the Rag-e- Sefid anticline in the southern Dezful Embayment
        Mehdi Yosefi Seyd Morteza Moussavi Mohammad Mahdi Khatib
        Plastic behavior and significant thickness of the Gachsaran incompetence formation on top of middle carbonate units in the sedimentary sequence of the southern Dezful Embayment led to the emergence of different styles of folding above and below of this formation. So tha More
        Plastic behavior and significant thickness of the Gachsaran incompetence formation on top of middle carbonate units in the sedimentary sequence of the southern Dezful Embayment led to the emergence of different styles of folding above and below of this formation. So that the structures in the upper and lower parts of this formation are completely separated and do not match each other. In the upper anticlines, above the Gachsaran horizon, the calculation of the limbs angle, the main thrust slope and the percentage of forelimb thickening indicate the fault detachment fold style. This style marks the geometry of fold at the early stage of the development of this anticline. Also the seismic profiles below the Gachsaran horizon also show the fault-propagation folding style. In the south Dezful Embayment, folding in the Gachsaran Formation occurs with shorter wavelengths in the form of disharmonic folds. This folding acts as the decoupling surface for the lower folds so that the synclines in this moving horizon directly cover the lower anticlines. The rounded folds in the carbonates in lower anticline are the imposed folds associated with steepened up reverse faults, detached on the basal decollement level and ultimately faulted by progressive deformation. The interpretation of seismic sections in the southern Dezful Embayment shows that lateral migration occurs in the salt units of the GS2 and GS4, and the upper and lower units of the Gachsaran Formation do not play a role in salt migration. Lateral migration in Miocene salts of the Gachsaran Formation is accomplished by the growth of sub-anticline during folding and loading of upper formation at the upper Gachsaran Formation. Manuscript profile
      • Open Access Article

        4 - Difference of in situ stress regime dependent on Structural position and geomechanical characteristics, Case study- Gachsaran and Asmari formations, SW Iran
        Hossein Talebi Seyd Ahmad Alavi Mohamad Reaz Ghasemi Shahram Sherkati
        Estimation of in-situ stress tensor in sedimentary basins using information obtained from exploration and development oil and gas wells during the drilling and logging process may be used for estimation of in-situ stress tensor in sedimentary basins. The in-situ stress More
        Estimation of in-situ stress tensor in sedimentary basins using information obtained from exploration and development oil and gas wells during the drilling and logging process may be used for estimation of in-situ stress tensor in sedimentary basins. The in-situ stress magnitude and orientation and the resulting stress regime around the studied wells have been several application in secondary recovery programs from hydrocarbon reservoirs as well as wellbore stability analysis. In this paper, the magnitude of in-situ stress is estimated by using abovementioned data in some oil wells located in the south west of Iran. Increasing the oil production by hydraulic fracturing design and sand control in the multi-layer reservoirs such as the Marun giant oil field with loose sand horizons and also improving drilling performance in the Gachsaran formation¬ requires knowledge about the prevailing stress conditions. This research, tries to analyze the stress regime of the Asmari and Gachsaran Formations around the selected wells in the Marun and Lali fields using constructed Mechanical Earth Models (MEM) and their differences are discussed. The calculated stress magnitudes in studied wells indicate a significant drop in magnitude of horizontal stresses from the Gachsaran to Asmari reservoirs in the Marun oil field. The magnitudes of the three principal stresses resulted that SHmax is the maximum principal stress and the Shmin is the minimum principal stress, thus a strike-slip stress regime (SHmax>Sv>Shmin) dominates in the Gachsaran sequence and the Asmari formation of the Lali oil field. however, in the Gachsaran formation of Marun giant oil field, stress regime is reverse-strike slip but normal stress regime is dominated in it's Asmari reservoir. The In-situ stress condition indicates that the structural condition and the depth difference of these structures plays an important role in the tectonic stress regime changes. Manuscript profile
      • Open Access Article

        5 - Microfacies and palaeoecology of the Asmari Formation in southeast flank of the Khami anticline (east of Gachsaran) and Correlation with two other sections of the Asmari Formation in the Zagros Basin
        همتا رنجبر علی رحمانی
        Abstract In order to characterize the features of facies and depositional environment conditions of the Asmari Formation in southeast flank of the Khami anticline with a thickness of 270 m has been studied. the Field and laboratory studies, led to the identification More
        Abstract In order to characterize the features of facies and depositional environment conditions of the Asmari Formation in southeast flank of the Khami anticline with a thickness of 270 m has been studied. the Field and laboratory studies, led to the identification 12 microfacies (nummulitidae lepidocyclina packestone/rodestone, corallinacea benthic foraminifera (perforate) packstone, bioclast neorotalia packestone, ooid grainstone, bioclast grainstone, miliolid neorotalia nummulitidae packestone, miliolid corallinacea coral floatstone/grainstone, bioclast benthic foraminifera (imperforate) packstone/grainstone, miliolid packstone/grainstone, sandy mudstone, intraclast mudstone) that deposited in continental slope, shoal, lagoon and tidal flat. In three different salinity facies environment from 34 psu to over 50 psu in oligoophotic to euphotic environment and oligotrophy-weak mesotrophy to eutrophy conditions in a homoclinal carbonate ramp platform recognized for the Asmari Formation at this study area. Correlation of the Asmari Formation in 3 section, A water salinity environmental correlation of the Asmari Formaion from Firozabad to east and north of Gachsaran reveals that 1- during Rupelian the Asmari Formation deposited in a normal water salinity environment, 2- while normal salinity water condition prevailed in Gachsaran area during Chattian, the Fars area was under higher marine salinity environment. Higher salinity environment developed during Aquitanian and Burdigalian in Gachsaran area. Manuscript profile
      • Open Access Article

        6 - Microfacies and palaeoecology of the Asmari Formation in southeast flank of the Khami anticline (east of Gachsaran) and Correlation with two other sections of the Asmari Formation in the Zagros Basin
        همتا رنجبر علی رحمانی
        Abstract In order to characterize the features of facies and depositional environment conditions of the Asmari Formation in southeast flank of the Khami anticline with a thickness of 270 m has been studied. the Field and laboratory studies, led to the identification More
        Abstract In order to characterize the features of facies and depositional environment conditions of the Asmari Formation in southeast flank of the Khami anticline with a thickness of 270 m has been studied. the Field and laboratory studies, led to the identification 12 microfacies (nummulitidae lepidocyclina packestone/rodestone, corallinacea benthic foraminifera (perforate) packstone, bioclast neorotalia packestone, ooid grainstone, bioclast grainstone, miliolid neorotalia nummulitidae packestone, miliolid corallinacea coral floatstone/grainstone, bioclast benthic foraminifera (imperforate) packstone/grainstone, miliolid packstone/grainstone, sandy mudstone, intraclast mudstone) that deposited in continental slope, shoal, lagoon and tidal flat. In three different salinity facies environment from 34 psu to over 50 psu in oligoophotic to euphotic environment and oligotrophy-weak mesotrophy to eutrophy conditions in a homoclinal carbonate ramp platform recognized for the Asmari Formation at this study area. Correlation of the Asmari Formation in 3 section, A water salinity environmental correlation of the Asmari Formaion from Firozabad to east and north of Gachsaran reveals that 1- during Rupelian the Asmari Formation deposited in a normal water salinity environment, 2- while normal salinity water condition prevailed in Gachsaran area during Chattian, the Fars area was under higher marine salinity environment. Higher salinity environment developed during Aquitanian and Burdigalian in Gachsaran area. Manuscript profile
      • Open Access Article

        7 - Microfacies and palaeoecology of the Asmari Formation in southeast flank of the Khami anticline (east of Gachsaran) and Correlation with two other sections of the Asmari Formation in the Zagros Basin
        همتا رنجبر علی رحمانی
        Abstract In order to characterize the features of facies and depositional environment conditions of the Asmari Formation in southeast flank of the Khami anticline with a thickness of 270 m has been studied. the Field and laboratory studies, led to the identification More
        Abstract In order to characterize the features of facies and depositional environment conditions of the Asmari Formation in southeast flank of the Khami anticline with a thickness of 270 m has been studied. the Field and laboratory studies, led to the identification 12 microfacies (nummulitidae lepidocyclina packestone/rodestone, corallinacea benthic foraminifera (perforate) packstone, bioclast neorotalia packestone, ooid grainstone, bioclast grainstone, miliolid neorotalia nummulitidae packestone, miliolid corallinacea coral floatstone/grainstone, bioclast benthic foraminifera (imperforate) packstone/grainstone, miliolid packstone/grainstone, sandy mudstone, intraclast mudstone) that deposited in continental slope, shoal, lagoon and tidal flat. In three different salinity facies environment from 34 psu to over 50 psu in oligoophotic to euphotic environment and oligotrophy-weak mesotrophy to eutrophy conditions in a homoclinal carbonate ramp platform recognized for the Asmari Formation at this study area. Correlation of the Asmari Formation in 3 section, A water salinity environmental correlation of the Asmari Formaion from Firozabad to east and north of Gachsaran reveals that 1- during Rupelian the Asmari Formation deposited in a normal water salinity environment, 2- while normal salinity water condition prevailed in Gachsaran area during Chattian, the Fars area was under higher marine salinity environment. Higher salinity environment developed during Aquitanian and Burdigalian in Gachsaran area. Manuscript profile
      • Open Access Article

        8 - Determination of In-situ stress in the Marun oilfield’s failure wells
        میثم فارسی مدان مرتضی احمدی کاوه آهنگری جاسم  دشت بزرگی
        Abstract Determination of In-situ stress domain in oilfields is so important for drilling, well completion and petroleum geomechanics. Simply, determination of magnitude and direction of In-situ stress around wellbore is the first step of geomechanical studies and we More
        Abstract Determination of In-situ stress domain in oilfields is so important for drilling, well completion and petroleum geomechanics. Simply, determination of magnitude and direction of In-situ stress around wellbore is the first step of geomechanical studies and wellbore stability particularly. Preliminarily, because of importance of casing collapse problem in the Marun oilfield, the magnitude of in-situ stress is determined. The magnitude of vertical stress (Sv) was in range of 85 to 90 MPa. The minimum horizontal stress (Shmin) determined by some analytical methods. For estimating of maximum horizontal stress (SHmax) domain we used Anderson’s faulting theory and stress polygon. So the magnitude of SHmax was so close to Sv and the faulting regime shows normal/strike slip. Within Gachsaran Formation in depth of collapses because of salty lithology and high pore pressure, magnitude of In-situ stress is so close and it can be assume hydrostatic stress state. Manuscript profile
      • Open Access Article

        9 - Evaluation of hydrocarbon potential of Gadvan Formation in Binak, Gachsaran and Marun fileds by geochemical methods and thermal modeling.
        نغمه مرتاضیان
        Investigation on hydrocarbon source rock potentiality of Gadvan Formation in Marun, Gachsaran and Binak oil fields using Rock-eval pyrolysis shows that Gadvan Formation in Marun and Gachsaran oil fields is an effective source rock and is capable of generating hydrocar More
        Investigation on hydrocarbon source rock potentiality of Gadvan Formation in Marun, Gachsaran and Binak oil fields using Rock-eval pyrolysis shows that Gadvan Formation in Marun and Gachsaran oil fields is an effective source rock and is capable of generating hydrocarbon (oil and gas) , whereas the same formation in the Binak oil field has no hydrocarbon generation potential. The presence of organic matter in Gadvan Formation from Marun and Gachsaran oil fields suggests a mixture of kerogen type II/III and in Binak oil field kergen type III is dominant. Based on Tmax values derived from Rock-Eval pyrolysis, Gadvan Formation in Marun and Gachsaran oil fields is thermally mature and entered oil window stage but in Binak oil field this formation is immature and has not entered oil window yet. The results obtained from pyrolysis and virtinite reflectance measurements are in good agreement with thermal history modeling using PBM software program. Organic facies curve plotted for the Gadvan Formation indicates organic facies BC for Marun and Gachsaran oil fields and organic facies CD for Binak oil field suggesting marine persistent anoxic to oxidizing conditions prevailed during early deposition Manuscript profile
      • Open Access Article

        10 - Evaluation of hydrocarbon potential of Gadvan Formation in Binak, Gachsaran and Marun fileds by geochemical methods and thermal modeling
        نغمه مرتاضیان
        Investigation on hydrocarbon source rock potentiality of Gadvan Formation in Marun, Gachsaran and Binak oil fields using Rock-eval pyrolysis shows that Gadvan Formation in Marun and Gachsaran oil fields is an effective source rock and is capable of generating hydrocarbo More
        Investigation on hydrocarbon source rock potentiality of Gadvan Formation in Marun, Gachsaran and Binak oil fields using Rock-eval pyrolysis shows that Gadvan Formation in Marun and Gachsaran oil fields is an effective source rock and is capable of generating hydrocarbon (oil and gas) , whereas the same formation in the Binak oil field has no hydrocarbon generation potential. The presence of organic matter in Gadvan Formation from Marun and Gachsaran oil fields suggests a mixture of kerogen type II/III and in Binak oil field kergen type III is dominant. Based on Tmax values derived from Rock-Eval pyrolysis, Gadvan Formation in Marun and Gachsaran oil fields is thermally mature and entered oil window stage but in Binak oil field this formation is immature and has not entered oil window yet. The results obtained from pyrolysis and virtinite reflectance measurements are in good agreement with thermal history modeling using PBM software program. Organic facies curve plotted for the Gadvan Formation indicates organic facies BC for Marun and Gachsaran oil fields and organic facies CD for Binak oil field suggesting marine persistent anoxic to oxidizing conditions prevailed Manuscript profile
      • Open Access Article

        11 - Investigation of corrosion of metals in oil pipes: a case study of Gachsaran Oil Company
        Omid   Fard ali aram
        Analysis of a dynamic light scattering instrument "Wyatt DynoproNanoStar" was used to detect the accumulation of surfactant in the oil phase. Triple measurements were performed for each sample and at least two samples were tested for each level of surfactant concentrati More
        Analysis of a dynamic light scattering instrument "Wyatt DynoproNanoStar" was used to detect the accumulation of surfactant in the oil phase. Triple measurements were performed for each sample and at least two samples were tested for each level of surfactant concentration to ensure reproducibility. The detection temperature was controlled at the same temperature by segmentation experiments. The accumulation properties of BAC surfactant in toluene were investigated using DLS and samples were presented in Figure 3, including the total radius and intensity of the collected light signal, C12, C14, and toluene C16, from the oil phase in the water-oil partitioning equilibrium from the surface. Net BAC was sampled. As can be seen, both the particle radius and the intensity of the C12 and C14 signals varied sharply within the evaluated concentration range, indicating that C12 and C14 do not form micelles in toluene. In this research, a multi-physical model, integrated corrosion inhibition model (ICI), is presented theoretically and empirically to evaluate integrated water-oil separation, aggregation, adsorption / desorption, and corrosion inhibition of mixed surfactant inhibitors in water-containing oils. We pay salt in Gachsaran Oil Company. Steel Pipe Environments (WOS). The ICI model is based on three main sub-models that consider water-oil surfactant classification, micellation, effective adsorption / desorption on the substrate, surfactant type, surfactant-solvent interactions, surfactant-contrion pair, and side surfactant interactions, etc. opnions have been asked. Acts as a basic framework in the design, selection, optimization, and use of various pure and mixed surfactant inhibitors in WOS environments. In summary, a comprehensive model, the ICI model, has been theoretically developed and empirically validated to evaluate the partitioning, aggregation, and corrosion inhibition of surfactant (both homologous and inhomogeneous) inhibitors (water-containing) and oil-steel pipe. Manuscript profile
      • Open Access Article

        12 - A review on external coaptation methods in small animal
        pouriya almasi Aboutorab  Tabatabaei Naeini
        External fixation by means of coaptation means using casts, splints, bandages, and slings to immobilize the injured limb. These methods if used properly approximate the shape of the limb on which they are applied and provide stable fixation of bone fragments without the More
        External fixation by means of coaptation means using casts, splints, bandages, and slings to immobilize the injured limb. These methods if used properly approximate the shape of the limb on which they are applied and provide stable fixation of bone fragments without the need for surgical implants at the fracture site. External fixation of orthopedic injuries in veterinary medicine has significant advantages over open fixation and internal fixation. In most cases, the soft tissue and vascular damages, the risk of infection, and the cost of its use can be much lower than surgical intervention. Careful case selection is required to achieve successful treatment of fractures with external coaptation. Temporary fixation methods are usually used to prevent edema, relieve pain, reduce subsequent soft tissue damage, protect the wound from further contamination, prevent the conversion of closed fractures to open fractures, and stabilize the fractured particles in acutely injured animals. Various types of External coaptations are available in veterinary practice to provide the best external fixation of injuries. Therefore, it is essential for the practitioners in this field to have sufficient familiarity with different methods and their uses. As a general rule, external coaptation is an acceptable mode of fracture repair for animals that are younger than 1 year of age, because they heal faster. External coaptation best neutralizes flexion forces on distal fractures and requires stabilization of the joint above and below the fractured site. Therefore, coaptation has the disadvantage of prolonged immobilization of the limb, which can cause severe atrophy from "disuse atrophy" and possible "fracture disease". Manuscript profile
      • Open Access Article

        13 - Employing different techniques to explore, modeling and reserve estimation of gypsum deposit in the northwest of Tafresh district, Markazi province
        Reza Ahmadi
        <p>In the present research, to explore gypsum reserves in the northwest of Tafresh district, a complete process including prospecting to reserve estimation has been carried out. To achieve the goal, first, an extensive area of 4500 km2 was investigated using remote sens More
        <p>In the present research, to explore gypsum reserves in the northwest of Tafresh district, a complete process including prospecting to reserve estimation has been carried out. To achieve the goal, first, an extensive area of 4500 km2 was investigated using remote sensing operation through Landsat 8 Operational Land Imager (OLI) images. Using proper pre-processing and processing techniques containing principal component analysis, false color band combination, least squares regression and spectral angle mapper on the images, 17 promising areas scattered in the region were identified. Based on more detailed studies and field surveys of the promising areas, it was specially focused on Darbar gypsum deposit located nearby Darbar village. Therefore, a variety of exploratory activities comprising six trenches with a total volume of 135.61 m3, one stope (selective mining unit), 1:1000 topographic-geological map, chemical analysis of 9 samples and drilling of one exploratory borehole with a depth of about 40 m was performed. The results of the chemical analysis of the samples show that the total percentage of SO3 and CaO compounds for all tested samples is more than 76%. In addition, the result of the technological test to determine the quality characteristics of the stone and baking ability in the pilot scale evaluated by Nizar Cement Factory of Qom is desirable. Gypsum modeling and reserve estimation of this deposit were also done with the classical method of contour lines using Surfer software. Based on the calculations, the in-place reserve of Darbar gypsum deposit was estimated significant amount of 5982610 tons.</p> Manuscript profile