University of TehranGeopersia2228-78171220111101Editor’s NoteEditor’s Note112327710.22059/jgeope.2011.23277EN--Editor’s NoteJournal Article19700101I am delighted to announce completion of the second issue of the new journal of “Geopersia”, a product of the new era of replacing the Persian language journals with specific English-language ones. Our purpose is to provide a journal that offers a multi-disciplinary analysis of issues concerning Geology subjects (i.e. sedimentology, stratigraphy, paleontology, Petroleum Geology, Engineering Geology, Tectonics, Economic Geology, Petrololgy and all other aspects of Geology). The journal will strive to combine academic excellence with professional relevance. We try to fill the gap of the great existing need for an English-language journal for our geologist academics and to become the principal forum for an inter-disciplinary dialogue between our geologist researchers. This new journal is built on the premise that a multi-disciplinary approach to the Geology sectors and to encourage an inter-disciplinary dialogue with and between our authors; that requires intelligibility across the borders of the authors’ specialities.I am delighted to announce completion of the second issue of the new journal of “Geopersia”, a product of the new era of replacing the Persian language journals with specific English-language ones. Our purpose is to provide a journal that offers a multi-disciplinary analysis of issues concerning Geology subjects (i.e. sedimentology, stratigraphy, paleontology, Petroleum Geology, Engineering Geology, Tectonics, Economic Geology, Petrololgy and all other aspects of Geology). The journal will strive to combine academic excellence with professional relevance. We try to fill the gap of the great existing need for an English-language journal for our geologist academics and to become the principal forum for an inter-disciplinary dialogue between our geologist researchers. This new journal is built on the premise that a multi-disciplinary approach to the Geology sectors and to encourage an inter-disciplinary dialogue with and between our authors; that requires intelligibility across the borders of the authors’ specialities.University of TehranGeopersia2228-78171220111101covercover112327810.22059/jgeope.2011.23278EN--coverJournal Article19700101Geopersia is published biannually by the College of Science, University of Tehran, Iran. The College of Science published Journal of Science, which covered all fields of basic science, from 1968 to 2010. It was then decided that the College’s journals should be more specialized, and hence publication of Geopersia was launched. Articles printed in Geopersia will be available online too.
Aims and scope
Geopersia aims to publish peer-reviewed original research articles related to the geology sciences that are timely and sufficiently reflect progress in these sciences. The research topics may relate to, Petroleum Geology, Geochemistry, Seismology, Sedimentology, Stratigraphy, Petrology, tectonics. Basic, applied, and technical findings and advances will be publishedGeopersia is published biannually by the College of Science, University of Tehran, Iran. The College of Science published Journal of Science, which covered all fields of basic science, from 1968 to 2010. It was then decided that the College’s journals should be more specialized, and hence publication of Geopersia was launched. Articles printed in Geopersia will be available online too.
Aims and scope
Geopersia aims to publish peer-reviewed original research articles related to the geology sciences that are timely and sufficiently reflect progress in these sciences. The research topics may relate to, Petroleum Geology, Geochemistry, Seismology, Sedimentology, Stratigraphy, Petrology, tectonics. Basic, applied, and technical findings and advances will be publishedUniversity of TehranGeopersia2228-78171220111101A committee machine approach for predicting permeability from well log data: a case study from a heterogeneous carbonate reservoir, Balal oil Field, Persian GulfA committee machine approach for predicting permeability from well log data: a case study from a heterogeneous carbonate reservoir, Balal oil Field, Persian Gulf1102327910.22059/jgeope.2011.23279ENAliKadkhodaieUniversity of TabrizBehrouzRafieiMohammadYosefpourGeology Division, Iranian Offshore Oil Company/ NIOC, Tehran, IranSaeedKhodabakhshJournal Article19700101Permeability prediction problem has been examined using several methods such as empirical formulas, regression analysis and intelligent systems especially neural networks and fuzzy logic. This study proposes an improved and novel model for predicting permeability from conventional well log data. The methodology is integration of empirical formulas, multiple regression and neuro-fuzzy in a committee machine. A committee machine, a new type of neural network, has a parallel structure in which each of the applied methods (experts) has a weight coefficient showing its contribution in overall prediction. The optimal combination of the weights is obtained by a genetic algorithm. The method is illustrated using a case study from a heterogeneous Upper Jurassic carbonate reservoir in Balal oil Field, Persian Gulf. For this purpose, one hundred fifty-one samples from the intervals comprising core and well log data were clustered into eighty-one training sets and seventy testing sets to evaluate the validity of the models developed. The results of this study show that the genetic algorithm optimized committee machine has provided more accurate results than each of individual experts usedPermeability prediction problem has been examined using several methods such as empirical formulas, regression analysis and intelligent systems especially neural networks and fuzzy logic. This study proposes an improved and novel model for predicting permeability from conventional well log data. The methodology is integration of empirical formulas, multiple regression and neuro-fuzzy in a committee machine. A committee machine, a new type of neural network, has a parallel structure in which each of the applied methods (experts) has a weight coefficient showing its contribution in overall prediction. The optimal combination of the weights is obtained by a genetic algorithm. The method is illustrated using a case study from a heterogeneous Upper Jurassic carbonate reservoir in Balal oil Field, Persian Gulf. For this purpose, one hundred fifty-one samples from the intervals comprising core and well log data were clustered into eighty-one training sets and seventy testing sets to evaluate the validity of the models developed. The results of this study show that the genetic algorithm optimized committee machine has provided more accurate results than each of individual experts usedUniversity of TehranGeopersia2228-78171220111101Use of feldspar grains in provenance determination and the study of transportation and depositional history, examples from central and NW IranUse of feldspar grains in provenance determination and the study of transportation and depositional history, examples from central and NW Iran11242328010.22059/jgeope.2011.23280ENAbdolhosseinAminiUniversity of TehranJournal Article19700101Feldspar grains, as a significant provenance indicator, of two terrigenous formations from Central Iran, the Upper Red Formation, and Moghan area, Zivah Formation, are used for provenance determination and the study of transportation and depositional history. The Upper Red Formation (URF) is volumetrically the most important siliciclastic unit of the Central Iran and Zivah Formation (ZF) represents the most important hydrocarbon reservoir in northwest Iran. Two representative sections of the URF in the southern foot hills of Central Alborz and three representative sections of the ZF in the northern foot hills of Talesh Mountains are investigated in this study. The sections represent best outcrops of the formations in their basin margin. Chemical composition, zoning and twining are the main characteristics of the feldspar grains used for this study. Results from facies analysis of the formations show that ~68% of the URF and ~73% of the ZF facies are suitable for this study, for having considerable amount of feldspar grains (>5% detrital feldspars).Feldspar grains, as a significant provenance indicator, of two terrigenous formations from Central Iran, the Upper Red Formation, and Moghan area, Zivah Formation, are used for provenance determination and the study of transportation and depositional history. The Upper Red Formation (URF) is volumetrically the most important siliciclastic unit of the Central Iran and Zivah Formation (ZF) represents the most important hydrocarbon reservoir in northwest Iran. Two representative sections of the URF in the southern foot hills of Central Alborz and three representative sections of the ZF in the northern foot hills of Talesh Mountains are investigated in this study. The sections represent best outcrops of the formations in their basin margin. Chemical composition, zoning and twining are the main characteristics of the feldspar grains used for this study. Results from facies analysis of the formations show that ~68% of the URF and ~73% of the ZF facies are suitable for this study, for having considerable amount of feldspar grains (>5% detrital feldspars).University of TehranGeopersia2228-78171220111101Stylolite networks in dolomitized limestones and their control on polished decorative stones:a case study from Upper Cretaceous Khur quarries, central IranStylolite networks in dolomitized limestones and their control on polished decorative stones:a case study from Upper Cretaceous Khur quarries, central Iran25372328110.22059/jgeope.2011.23281ENNaseerArzaniPayame Noor UniversityJournal Article19700101Stylolite networks and their insoluble residues (IR) are among the major concerns and the fundamental controls on the mining and processing of sedimentary decorative stones, largely made from dolomitized limestones. They are mainly used, as natural rock blocks and polished slabs, to construct and decorate floors and walls of buildings and monuments. Representative quarries in Khur areas, east of Esfahan Province, central Iran, are selected for this study in order to evaluate the type and geometry of the stylolite networks in differentially dolomitized limestones and their control on the quality of the mined rock blocks and processed polished rock slabs. Field observation, examining the mined wall-rock cuttings in quarries, and petrography of the selected thin sections of Upper Cretaceous Haftoman Formation were performed with a comparative study of thickly developed, rudist-bearing rudstones-grainstones to bioclastic packstone-wackestone microfacies. What is typically considered in this study is evaluating the geometry of stylolite networks (cells), as they merge and result in a 3D network, rather than laterally continuous single stylolites.Stylolite networks and their insoluble residues (IR) are among the major concerns and the fundamental controls on the mining and processing of sedimentary decorative stones, largely made from dolomitized limestones. They are mainly used, as natural rock blocks and polished slabs, to construct and decorate floors and walls of buildings and monuments. Representative quarries in Khur areas, east of Esfahan Province, central Iran, are selected for this study in order to evaluate the type and geometry of the stylolite networks in differentially dolomitized limestones and their control on the quality of the mined rock blocks and processed polished rock slabs. Field observation, examining the mined wall-rock cuttings in quarries, and petrography of the selected thin sections of Upper Cretaceous Haftoman Formation were performed with a comparative study of thickly developed, rudist-bearing rudstones-grainstones to bioclastic packstone-wackestone microfacies. What is typically considered in this study is evaluating the geometry of stylolite networks (cells), as they merge and result in a 3D network, rather than laterally continuous single stylolites.University of TehranGeopersia2228-78171220111101A fast and simple method for modeling of oil swelling in Co2 injectionA fast and simple method for modeling of oil swelling in Co2 injection39462328210.22059/jgeope.2011.23282ENJafarValiPetroleum IndustryEzatallahKazemzadehPetroleum IndustryHessamAloki BakhtiariPetroleum IndustryMortezaKhodabakhshiPetroleum Engineering Texas A&M UniversityMohammad RezaEsfahaniPetroleum IndustryJournal Article19700101In this paper, the role of molecular diffusion in mobilization of waterflood residual oil is examined. A moving mesh method is applied to solve the moving interface problem of residual oil blobs swelling by Co2 diffusion through a blocking water phase. The results of this modeling are compared with experimental results of a 2D glass micromodel experiment. Although, the solution method is applied for a 1D system, a good agreement between numerical and experimental results validates the solution method. In this method a fixed time step is proposed. Furthermore, the results of this method have been compared with the results of the Grogan’s finite difference method. This supposed that, the mesh network is fixed and time step increasing will be continued until the oil-swelling equal to one spatial step size.In this paper, the role of molecular diffusion in mobilization of waterflood residual oil is examined. A moving mesh method is applied to solve the moving interface problem of residual oil blobs swelling by Co2 diffusion through a blocking water phase. The results of this modeling are compared with experimental results of a 2D glass micromodel experiment. Although, the solution method is applied for a 1D system, a good agreement between numerical and experimental results validates the solution method. In this method a fixed time step is proposed. Furthermore, the results of this method have been compared with the results of the Grogan’s finite difference method. This supposed that, the mesh network is fixed and time step increasing will be continued until the oil-swelling equal to one spatial step size.University of TehranGeopersia2228-78171220111101Empirical correlation for porosity deduction from X-ray computed
tomography (CT)Empirical correlation for porosity deduction from X-ray computed
tomography (CT)47542328310.22059/jgeope.2011.23283ENKazemSaadatRIPI,Production Research CenterHossainRahimpour-BonabUniversity of Tehran0000-0003-3647-2897Mohammad RezaEsfahaniRIPI,Production Research CenterJafarValiRIPI,Production Research CenterJournal Article19700101For obtaining reservoir petrophysical properties, for example porosity, non-destructive methods such as X-ray computed
tomography, CT, seems to be precise and accurate. Porosity is deducted from the CT image with a single scan via
different techniques, such as pore space detection by image segmentation techniques then correlation with porosity. More
than one hundred samples with carbonate lithology have been scanned and analyzed in this study which leads to empirical
correlation used for porosity calculation from CT data. The samples mainly grouped as dolostone, limestone and
carbonate with respect to their mineral contents, having porosity ranges between 4.56 to 30.5 % and permeability from
0.25 to 3350.8 md. The results showed that the effect of atomic number is higher than the density on CT image. It is
because density and atomic number in carbonate mineral (calcite and dolomite) show diverse relations. Thus, the
assumption of known lithology would be a large source of error. A good linear relationship exists between the porosity
and CT no. according to the developed correlations.For obtaining reservoir petrophysical properties, for example porosity, non-destructive methods such as X-ray computed
tomography, CT, seems to be precise and accurate. Porosity is deducted from the CT image with a single scan via
different techniques, such as pore space detection by image segmentation techniques then correlation with porosity. More
than one hundred samples with carbonate lithology have been scanned and analyzed in this study which leads to empirical
correlation used for porosity calculation from CT data. The samples mainly grouped as dolostone, limestone and
carbonate with respect to their mineral contents, having porosity ranges between 4.56 to 30.5 % and permeability from
0.25 to 3350.8 md. The results showed that the effect of atomic number is higher than the density on CT image. It is
because density and atomic number in carbonate mineral (calcite and dolomite) show diverse relations. Thus, the
assumption of known lithology would be a large source of error. A good linear relationship exists between the porosity
and CT no. according to the developed correlations.University of TehranGeopersia2228-78171220111101Synthesis, characterization, stability and structure of solid solutions
between ?-miargyrite(AgSbS2) – smithite (AgAsS2) and ?- miargyrite -
smithiteSynthesis, characterization, stability and structure of solid solutions
between ?-miargyrite(AgSbS2) – smithite (AgAsS2) and ?- miargyrite -
smithite55662328410.22059/jgeope.2011.23284ENMortezaRazmaraFerdowsi University of MashhadRichardPattrickUniversity of ManchesterJournal Article19700101Sulphosalts in the system AgSbS2-AgAsS2 have been experimentally investigated using dry methods. The solid solutions
which form between ?-miargyrite and smithite have different structures. The EPMA data for the solid solution series show
that there is an inverse relation between Sb and As. The cell parameters of the solid solution between ?-miargyrite and
smithite increase up to about 50% of AgSbS2 substitution in the smithite structure and then reveal a structural phase
transition as a function of composition. Electron diffraction (TEM) data for ?-miargyrite is consistent with the space
group A2/a , but for the compositions Ag(As0.1Sb0.9)S2 and Ag(As0.3Sb0.7)S2, the phases do not show good Laue zones and
Kikuchi lines and the symmetry could be either monoclinic or triclinic. The variation in the DW factor derived from the
EXAFS spectra for the first shell of S atoms surrounding As in Ag(As0.3Sb0.7)S2 tends to be smaller than for AgAsS2
indicating that the As environment in Ag(As0.3Sb0.7)S2 is more ordered than in Ag(As0.5Sb0.5)S2 and AgAsS2. This ordering
indicates that with more substitution of Sb in AgAsS2, the monoclinic (A2/a) Ag(As0.5Sb0.5)S2 collapses around As atoms
to a probable low-monoclinic or triclinic structure.Sulphosalts in the system AgSbS2-AgAsS2 have been experimentally investigated using dry methods. The solid solutions
which form between ?-miargyrite and smithite have different structures. The EPMA data for the solid solution series show
that there is an inverse relation between Sb and As. The cell parameters of the solid solution between ?-miargyrite and
smithite increase up to about 50% of AgSbS2 substitution in the smithite structure and then reveal a structural phase
transition as a function of composition. Electron diffraction (TEM) data for ?-miargyrite is consistent with the space
group A2/a , but for the compositions Ag(As0.1Sb0.9)S2 and Ag(As0.3Sb0.7)S2, the phases do not show good Laue zones and
Kikuchi lines and the symmetry could be either monoclinic or triclinic. The variation in the DW factor derived from the
EXAFS spectra for the first shell of S atoms surrounding As in Ag(As0.3Sb0.7)S2 tends to be smaller than for AgAsS2
indicating that the As environment in Ag(As0.3Sb0.7)S2 is more ordered than in Ag(As0.5Sb0.5)S2 and AgAsS2. This ordering
indicates that with more substitution of Sb in AgAsS2, the monoclinic (A2/a) Ag(As0.5Sb0.5)S2 collapses around As atoms
to a probable low-monoclinic or triclinic structure.University of TehranGeopersia2228-78171220111101Petrology and geochemistry of Aligoodarz granitoid, Western Iran: implications for petrogenetic relation with Boroujerd and Dehno granitoidsPetrology and geochemistry of Aligoodarz granitoid, Western Iran: implications for petrogenetic relation with Boroujerd and Dehno granitoids67862328510.22059/jgeope.2011.23285ENAmirEsna-AshariUniversity of TehranMohammadVali ValizadehUniversity of TehranAbolfazlSoltaniUniversity of Shahid Rajaee, LavizanAliAsghar SepahiBu-Ali Sina University, HamadanJournal Article19700101The Aligoodarz granitoid occurs in Sanandaj-Sirjan Zone (SSZ), Western Iran. Tonalite, granodiorite and granite are the main rock types cropping out in the area. Comparison of Aligoodarz granitoid with Dehno and Boroujerd granitoids reveals several similarities in their chemical characteristics. Thus, the above mentioned granitoids can be assigned as a co-genetic magmatic suite, in which plutons evolved from a parental magma; with fractional crystallization being the main mechanism for magma evolution. Samples with lower SiO2 content from different areas, are not similar in composition, and indicating varying degrees of mineral accumulation and trapped interstitial melts. These granitoids are compositionally similar to normal I-type granitoid rocks originated from continental arcs. Compared with the primordial mantle, they are enriched in Large Ion Lithophile Elements (LILE) and Light Rare Earth Elements (LREE) over High Field Strength Elements (HFSE) and Heavy Rare Earth Elements (HREE). This feature together with relative depletion of Ta, Nb, Ti, and P confirm derivation of these granitoids from a crustal source region in continental arc environmentThe Aligoodarz granitoid occurs in Sanandaj-Sirjan Zone (SSZ), Western Iran. Tonalite, granodiorite and granite are the main rock types cropping out in the area. Comparison of Aligoodarz granitoid with Dehno and Boroujerd granitoids reveals several similarities in their chemical characteristics. Thus, the above mentioned granitoids can be assigned as a co-genetic magmatic suite, in which plutons evolved from a parental magma; with fractional crystallization being the main mechanism for magma evolution. Samples with lower SiO2 content from different areas, are not similar in composition, and indicating varying degrees of mineral accumulation and trapped interstitial melts. These granitoids are compositionally similar to normal I-type granitoid rocks originated from continental arcs. Compared with the primordial mantle, they are enriched in Large Ion Lithophile Elements (LILE) and Light Rare Earth Elements (LREE) over High Field Strength Elements (HFSE) and Heavy Rare Earth Elements (HREE). This feature together with relative depletion of Ta, Nb, Ti, and P confirm derivation of these granitoids from a crustal source region in continental arc environmentUniversity of TehranGeopersia2228-78171220111101Volume1 refereesVolume1 referees991002328610.22059/jgeope.2011.23286EN--Volume 1 RefereesJournal Article19700101Following is a list of our colleagues who volunteered to review the manuscripts received to Geopersia during the past 12 months. I appreciate the positive actions that you have taken to participate in reviewing the manuscripts and implementing our recommendations to get the two issues published. We certainly would not be able to continue without your support and I wish to acknowledge your continued support for the coming issues and look forward to our joint continuing work in the future. Dr. Ebrahim Ghasemi-Nejad (Editor in Chief of Geopersia).We certainly would not be able to continue without your support and I wish to acknowledge your continued support for the coming issues and look forward to our joint continuing work in the future. Dr. Ebrahim Ghasemi-Nejad (Editor in Chief of Geopersia).Following is a list of our colleagues who volunteered to review the manuscripts received to Geopersia during the past 12 months. I appreciate the positive actions that you have taken to participate in reviewing the manuscripts and implementing our recommendations to get the two issues published. We certainly would not be able to continue without your support and I wish to acknowledge your continued support for the coming issues and look forward to our joint continuing work in the future. Dr. Ebrahim Ghasemi-Nejad (Editor in Chief of Geopersia).We certainly would not be able to continue without your support and I wish to acknowledge your continued support for the coming issues and look forward to our joint continuing work in the future. Dr. Ebrahim Ghasemi-Nejad (Editor in Chief of Geopersia).