University of TehranGeopersia2228-78172220121201Thermal modeling and organic geochemical appraisal of petroleum source rocks within the Aghajari Oilfield, SW IranThermal modeling and organic geochemical appraisal of petroleum source rocks within the Aghajari Oilfield, SW Iran1102922810.22059/jgeope.2012.29228ENBahramAlizadehChamran University of AhvazBehzadaKhaniChamran University of AhvazMajidAlipourChamran University of AhvazMasoudShayestehNational Iranian South Oil Company (NISOC)Seyed HosseinHosseiniChamran University of AhvazJournal Article19700101Dezful embayment contains several potential source rocks deposited in tectonically active environments. Existence of various source rocks with different geological ages makes this area one of the most prolific regions throughout the Middle East. The Pabdeh Formation (Lower Paleocene-Eocene), the Gurpi Formation (Santonian-Masstrichtian), the Kazhdumi Formation (Albian) and the Gadvan Formation (Neocomian-Aptian) are among the most favorable source rocks within the embayment. In this study the set of above mentioned source rocks are subject to pyrolysis in Aghajari Oilfield. Results reveal that the Kazhdumi Formation with highest TOC (4.43%) in compare to other probable source rocks has higher hydrocarbon generative potential and is the likeliest source rock responsible for the Asmari and Bangestan reservoirs in the Aghajari Oilfield. Moreover, the pyrolysis of Pabdeh, Gurpi and Gadvan formations show that they are of minor importance as potential source rocks within the studied Oilfield. The burial and thermal history of the Kazhdumi Formation was modeled to infer about the probable time of the hydrocarbon generation. According to Burial history profile and thermal modeling the beginning of the oil window for Kazhdumi Formation was dated at 13Ma. Moreover, the depth of oil expulsion is around 3800m in 9 Ma years ago.Dezful embayment contains several potential source rocks deposited in tectonically active environments. Existence of various source rocks with different geological ages makes this area one of the most prolific regions throughout the Middle East. The Pabdeh Formation (Lower Paleocene-Eocene), the Gurpi Formation (Santonian-Masstrichtian), the Kazhdumi Formation (Albian) and the Gadvan Formation (Neocomian-Aptian) are among the most favorable source rocks within the embayment. In this study the set of above mentioned source rocks are subject to pyrolysis in Aghajari Oilfield. Results reveal that the Kazhdumi Formation with highest TOC (4.43%) in compare to other probable source rocks has higher hydrocarbon generative potential and is the likeliest source rock responsible for the Asmari and Bangestan reservoirs in the Aghajari Oilfield. Moreover, the pyrolysis of Pabdeh, Gurpi and Gadvan formations show that they are of minor importance as potential source rocks within the studied Oilfield. The burial and thermal history of the Kazhdumi Formation was modeled to infer about the probable time of the hydrocarbon generation. According to Burial history profile and thermal modeling the beginning of the oil window for Kazhdumi Formation was dated at 13Ma. Moreover, the depth of oil expulsion is around 3800m in 9 Ma years ago.https://geopersia.ut.ac.ir/article_29228_4d06842da29fe4c2abb3586252494f54.pdfUniversity of TehranGeopersia2228-78172220121201Electrofacies clustering and a hybrid intelligent based method for porosity and permeability prediction in the South Pars Gas Field, Persian GulfElectrofacies clustering and a hybrid intelligent based method for porosity and permeability prediction in the South Pars Gas Field, Persian Gulf11232922910.22059/jgeope.2012.29229ENEbrahimSfidariUniversity of TehranAbdolhosseinAminiUniversity of TehranAliKadkhodaieUniversity of TabrizBahmanAhmadiUniversity of Guilan, RashtJournal Article19700101This paper proposes a two-step approach for characterizing the reservoir properties of the world’s largest non-associated gas reservoir. This approach integrates geological and petrophysical data and compares them with the field performance analysis to achieve a practical electrofacies clustering. Porosity and permeability prediction is done on the basis of linear functions, succeeding the electrofacies clustering. At the start, an unsupervised neural network was employed based on the self-organizing map (SOM) technique to identify and extract electrofacies groups. No subdivision of the data set was required for the technique on account of the natural characters of the well logs that reflect lithological character of the formations. The second step was examining a supervised neural network which is designed based on the back propagation algorithm. This technique quantitatively predicts the porosity and permeability within the determined electrofacies. The final part of the study was calibration and comparison of the electrofacies clustering results with core and petrographic data. Based on the porosity and permeability maps at different depth levels, the target reservoir is classified into six electrofacies clusters (EF1-EF6) among which the EF5 and EF4 show the best reservoir quality.This paper proposes a two-step approach for characterizing the reservoir properties of the world’s largest non-associated gas reservoir. This approach integrates geological and petrophysical data and compares them with the field performance analysis to achieve a practical electrofacies clustering. Porosity and permeability prediction is done on the basis of linear functions, succeeding the electrofacies clustering. At the start, an unsupervised neural network was employed based on the self-organizing map (SOM) technique to identify and extract electrofacies groups. No subdivision of the data set was required for the technique on account of the natural characters of the well logs that reflect lithological character of the formations. The second step was examining a supervised neural network which is designed based on the back propagation algorithm. This technique quantitatively predicts the porosity and permeability within the determined electrofacies. The final part of the study was calibration and comparison of the electrofacies clustering results with core and petrographic data. Based on the porosity and permeability maps at different depth levels, the target reservoir is classified into six electrofacies clusters (EF1-EF6) among which the EF5 and EF4 show the best reservoir quality.https://geopersia.ut.ac.ir/article_29229_9650fc74882900898e1aa77d09f3a558.pdfUniversity of TehranGeopersia2228-78172220121201Late Maastrichtian benthic foraminiferal response to palaeoenvironmental changes: a case study from the AbTalkh Formation, west of Kopeh-Dagh Basin, IranLate Maastrichtian benthic foraminiferal response to palaeoenvironmental changes: a case study from the AbTalkh Formation, west of Kopeh-Dagh Basin, Iran25422923010.22059/jgeope.2012.29230ENShemshadGhoorchaeiFerdowsi University of MashhadMohammadVahidiniaFerdowsi University of MashhadAlirezaAshooriFerdowsi University of MashhadJournal Article19700101Benthic foraminiferal assemblages from Maastrichtian strata, Gansserina gansseri-Abathamphalus mayaroensis Planktonic Foraminiferal Zone, of the AbTalkh Formation at Aitamir section (west of the Kopeh-Dagh basin) were investigated in order to evaluate the palaeoenvironmental changes (organic matter flux and bottom-water oxygenation). Maastrichtian faunal assemblages are well preserved and diversified. Fluctuations in the percentage of infaunal and epifaunal morphogroups as well as simple diversity and heterogeneity index are recorded. The study indicates that an unstable environment with oligotrophic to weakly mesotrophic condition and high oxygenated bottom water condition was prevailed during the depositionof the sediments in the latest Cretaceous.Benthic foraminiferal assemblages from Maastrichtian strata, Gansserina gansseri-Abathamphalus mayaroensis Planktonic Foraminiferal Zone, of the AbTalkh Formation at Aitamir section (west of the Kopeh-Dagh basin) were investigated in order to evaluate the palaeoenvironmental changes (organic matter flux and bottom-water oxygenation). Maastrichtian faunal assemblages are well preserved and diversified. Fluctuations in the percentage of infaunal and epifaunal morphogroups as well as simple diversity and heterogeneity index are recorded. The study indicates that an unstable environment with oligotrophic to weakly mesotrophic condition and high oxygenated bottom water condition was prevailed during the depositionof the sediments in the latest Cretaceous.https://geopersia.ut.ac.ir/article_29230_0dbe152b435d929e0ad72217d51e74af.pdfUniversity of TehranGeopersia2228-78172220121201Mesozoic basin inversion in Central Alborz, evidence from the evolution of Taleqan-Gajereh-Lar paleograbenMesozoic basin inversion in Central Alborz, evidence from the evolution of Taleqan-Gajereh-Lar paleograben43632923110.22059/jgeope.2012.29231ENMohsenEhteshami-MoinabadiTarbiat Modares UniversityAliYassaghiTarbiat Modares UniversityAbdolhosseinAminiUniversity of TehranJournal Article19700101This paper presents evidence on Mesozoic inversion of basin bounding faults within the Taleqan-Gajereh-Lar Paleograben (TGLP) in Central Alborz Range. For this purpose, well documented stratigraphy data across the TGLP together with the new acquired structural data on the geometry and kinematics of the paleograben basin bounding faults are utilized. The TGLP has evolved through the Early and Middle Cimmerian and the Late Cretaceous tectonic events. The Early Cimmerian north verging folds of Paleozoic rocks with development of axial foliation is proposed to be related to inversion of the basin bounding Mosha and Hasanakdar faults. During the Middle Cimmerian (Bajocian), synchronous to opening of the Caspian basin, the TGLP was extended through the growth of the Gajereh half-graben on the hanging wall of the Mosha Fault. This half-graben that accommodated the thickest portion of the Jurassic rocks in the south Central Alborz is considered as the depocenter of Jurassic basin in this region. The Late Cretaceous-Early Paleocene event associated with folding, and thrust faulting of Jurassic and Cretaceous rocks, causes inversion of the TGLP along its north bounding Taleqan Fault. Development of an angular unconformity between the Eocene Karaj Formation and Mesozoic deposits is the result of this inversion.This paper presents evidence on Mesozoic inversion of basin bounding faults within the Taleqan-Gajereh-Lar Paleograben (TGLP) in Central Alborz Range. For this purpose, well documented stratigraphy data across the TGLP together with the new acquired structural data on the geometry and kinematics of the paleograben basin bounding faults are utilized. The TGLP has evolved through the Early and Middle Cimmerian and the Late Cretaceous tectonic events. The Early Cimmerian north verging folds of Paleozoic rocks with development of axial foliation is proposed to be related to inversion of the basin bounding Mosha and Hasanakdar faults. During the Middle Cimmerian (Bajocian), synchronous to opening of the Caspian basin, the TGLP was extended through the growth of the Gajereh half-graben on the hanging wall of the Mosha Fault. This half-graben that accommodated the thickest portion of the Jurassic rocks in the south Central Alborz is considered as the depocenter of Jurassic basin in this region. The Late Cretaceous-Early Paleocene event associated with folding, and thrust faulting of Jurassic and Cretaceous rocks, causes inversion of the TGLP along its north bounding Taleqan Fault. Development of an angular unconformity between the Eocene Karaj Formation and Mesozoic deposits is the result of this inversion.https://geopersia.ut.ac.ir/article_29231_6ddfa03fceb279451dd4269649755f9b.pdfUniversity of TehranGeopersia2228-78172220121201Using Miniature Cone Penetration Test (Mini-CPT) to determine engineering properties of sandy soilsUsing Miniature Cone Penetration Test (Mini-CPT) to determine engineering properties of sandy soils65762923210.22059/jgeope.2012.29232ENMohammad RezaNikudelTarbiat Modares UniversitySeyed EhsanMousaviTarbiat Modares UniversityMashaallahKhamehchiyanTarbiat Modares UniversityAminJamshidiTarbiat Modares UniversityJournal Article19700101In-situ testing techniques have proven to be successful in improving the speed and reliability of geotechnical investigations. One of the most common in-situ methods in engineering geology and site investigation is Cone Penetration Test (CPT), which is mainly used for characterization of soils, as it is a robust, simple, fast, reliable and economic test that can provide continuous soundings of subsurface soil. Miniature Cone Penetration (Mini-CPT) Test is a new type of CPT but in diameter less than conventional CPT to determine the bearing capacity and strength parameters of loose to semi-dense soils at shallow depth. Mini-CPT needs lower force to penetrate into the soil, and its ability to identify very thin underneath layers is higher than CPT. In this research, a Mini-CPT apparatus was used in laboratory conditions to define the relationships between tip resistance (qc(MCPT)), friction resistance (fs(MCPT)) and some engineering properties of poorly graded sandy soils such as Relative Density (Dr), Friction Angle (?), Elastic Modulus (E), Shear Modulus (G), and the Modulus of Subgrade Reaction (Ks) with different densities. Based on the results of the experiments, the relationships between both the qc(MCPT) and fs(MCPT) with engineering properties were obtained with a high determination coefficient (R2>0.85).In-situ testing techniques have proven to be successful in improving the speed and reliability of geotechnical investigations. One of the most common in-situ methods in engineering geology and site investigation is Cone Penetration Test (CPT), which is mainly used for characterization of soils, as it is a robust, simple, fast, reliable and economic test that can provide continuous soundings of subsurface soil. Miniature Cone Penetration (Mini-CPT) Test is a new type of CPT but in diameter less than conventional CPT to determine the bearing capacity and strength parameters of loose to semi-dense soils at shallow depth. Mini-CPT needs lower force to penetrate into the soil, and its ability to identify very thin underneath layers is higher than CPT. In this research, a Mini-CPT apparatus was used in laboratory conditions to define the relationships between tip resistance (qc(MCPT)), friction resistance (fs(MCPT)) and some engineering properties of poorly graded sandy soils such as Relative Density (Dr), Friction Angle (?), Elastic Modulus (E), Shear Modulus (G), and the Modulus of Subgrade Reaction (Ks) with different densities. Based on the results of the experiments, the relationships between both the qc(MCPT) and fs(MCPT) with engineering properties were obtained with a high determination coefficient (R2>0.85).https://geopersia.ut.ac.ir/article_29232_4396b231406b95427060cfbd200e6ed6.pdfUniversity of TehranGeopersia2228-78172220121201A combined Wavelet- Artificial Neural Network model and its application to the prediction of groundwater level fluctuationsA combined Wavelet- Artificial Neural Network model and its application to the prediction of groundwater level fluctuations77912923310.22059/jgeope.2012.29233ENMohammadNakhaeiKharazmi UniversityAmir SaberiNasrKharazmi UniversityJournal Article19700101Accurate groundwater level modeling and forecasting contribute to civil projects, land use, citys planning and water resources management. Combined Wavelet-Artificial Neural Network (WANN) model has been widely used in recent years to forecast hydrological and hydrogeological phenomena. This study investigates the sensitivity of the pre-processing to the wavelet type and decomposition level in WANN model for groundwater level forecasting. To this end, the monthly groundwater level time series were collected from October 1997 to October 2007 in 26 piezometers of Qorveh aquifer, Iran. Using discrete wavelet transform method and different mother wavelets (Haar, db2, db3 and db4), these time series were decomposed into sub-signals in various resolution levels. Then, these sub-signals entered to the ANN model to reconstruct the original forecasted time series for 6 months ahead. The Root Mean Square Errors (RMSE) and coef?cient of determination (R2) statistics were used for evaluating the accuracy of the model. The results showed merits of db2 and db4 wavelets in comparison with Haar and db3 because of similarity between the signal of groundwater level and the functions of mother wavelets.Accurate groundwater level modeling and forecasting contribute to civil projects, land use, citys planning and water resources management. Combined Wavelet-Artificial Neural Network (WANN) model has been widely used in recent years to forecast hydrological and hydrogeological phenomena. This study investigates the sensitivity of the pre-processing to the wavelet type and decomposition level in WANN model for groundwater level forecasting. To this end, the monthly groundwater level time series were collected from October 1997 to October 2007 in 26 piezometers of Qorveh aquifer, Iran. Using discrete wavelet transform method and different mother wavelets (Haar, db2, db3 and db4), these time series were decomposed into sub-signals in various resolution levels. Then, these sub-signals entered to the ANN model to reconstruct the original forecasted time series for 6 months ahead. The Root Mean Square Errors (RMSE) and coef?cient of determination (R2) statistics were used for evaluating the accuracy of the model. The results showed merits of db2 and db4 wavelets in comparison with Haar and db3 because of similarity between the signal of groundwater level and the functions of mother wavelets.https://geopersia.ut.ac.ir/article_29233_6d5a574674d25fb43dd12995f4009483.pdfUniversity of TehranGeopersia2228-78172220121201Hydrothermal evolution of the Sar-Kuh porphyry copper deposit, Kerman, Iran: A fluid inclusion and sulfur isotope investigationHydrothermal evolution of the Sar-Kuh porphyry copper deposit, Kerman, Iran: A fluid inclusion and sulfur isotope investigation931072923410.22059/jgeope.2012.29234ENSoheilaNouraliUniversity of TehranHassanMirnejadUniversity of TehranJournal Article19700101Sar-Kuh porphyry copper deposit is located 6 km southwest of the Sar-Cheshmeh copper mine, Kerman Province, Iran. Based on field geology, petrography and fluid inclusions studies, four alteration types have been identified in the Sar-Kuh area. Early hydrothermal alteration formed a potassic zone in the central parts of Mamzar granite/grano-diorite stock and propylitic alteration in its peripheral parts. The late hydrothermal activity caused a limited phyllic and argillic alteration zones. The mineralized quartz veins are classified into four groups, on the basis of mineralogy and cross-cutting relationships. Group I and II veins are concentrated mainly in the potassic alteration zone, while group III and IV are most abundant in the phyllic and propylitic alteration zones, respectively. Fluid inclusion studies on group I and II quartz veins show that potassic alteration has originated from a dominantly magmatic fluid with high salinity (30-50 wt % NaCl equiv) and temperature (>300oC). The ?34S values of separated pyrite and chalcopyrite from samples range between +1.29‰ to +4.72‰ (mean value of +2.68‰), consistent with a magmatic origin for sulfur.Sar-Kuh porphyry copper deposit is located 6 km southwest of the Sar-Cheshmeh copper mine, Kerman Province, Iran. Based on field geology, petrography and fluid inclusions studies, four alteration types have been identified in the Sar-Kuh area. Early hydrothermal alteration formed a potassic zone in the central parts of Mamzar granite/grano-diorite stock and propylitic alteration in its peripheral parts. The late hydrothermal activity caused a limited phyllic and argillic alteration zones. The mineralized quartz veins are classified into four groups, on the basis of mineralogy and cross-cutting relationships. Group I and II veins are concentrated mainly in the potassic alteration zone, while group III and IV are most abundant in the phyllic and propylitic alteration zones, respectively. Fluid inclusion studies on group I and II quartz veins show that potassic alteration has originated from a dominantly magmatic fluid with high salinity (30-50 wt % NaCl equiv) and temperature (>300oC). The ?34S values of separated pyrite and chalcopyrite from samples range between +1.29‰ to +4.72‰ (mean value of +2.68‰), consistent with a magmatic origin for sulfur.https://geopersia.ut.ac.ir/article_29234_64e368a3bcb997d66f77cf67d317ec00.pdfUniversity of TehranGeopersia2228-78172220121201covercover112923510.22059/jgeope.2012.29235ENCoverCoveruniversity of tehranJournal Article19700101covercoverhttps://geopersia.ut.ac.ir/article_29235_2471ab324ff5741b0258570a9c37ab1a.pdfUniversity of TehranGeopersia2228-78172220121201volume2 refereesvolume2 referees112923610.22059/jgeope.2012.29236ENVolume2Refereesuniversity of tehranJournal Article19700101https://geopersia.ut.ac.ir/article_29236_2dcf3476ce8dc066916ace2729c303db.pdf