https://igj-iraq.org/igj/index.php/igj/issue/feed The Iraqi Geological Journal 2024-02-29T10:10:00+00:00 Iraqi Geological Journal info@igj-iraq.org Open Journal Systems <p>The <strong><em>Iraqi Geological Journal (IGJ)</em></strong> is a peer-reviewed and indexed journal, issued twice a year in English by the Union of Iraqi Geologists (UIG).&nbsp;</p> https://igj-iraq.org/igj/index.php/igj/article/view/2025 Detrital Chromian Spinel Geochemistry from Miocene Red Bed Sandstones of Northeastern Iraq: Implication for Provenance and Tectonic Setting 2024-02-29T10:09:59+00:00 Nabaz R.H. Aziz nabaz.hamaaziz@univsul.edu.iq <p>The provenance and tectonic setting of clastic sediments present in the Miocene Red Bed Series located in northeastern Iraq were analyzed. The analysis is based on the composition of detrital chrome spinel and represents the first examination of this topic. The detrital chrome spinel exhibits Cr # (Cr/(Cr + Al)) values ranging from 0.54 to 0.77 and Mg # (Mg/(Mg + Fe<sup>2+</sup>)) values ranging from 0.37 to 0.69. This indicates a potential incorporation of ultramafic sources, possibly including peridotites (namely Harzburgite and Lherzolite precursors), within the supra-subduction zone. The analysis of modified Cr-spinels extracted from the Red Beds indicates that the source rocks underwent a process of metamorphism and that the Cr-spinel particles were surrounded by a magnetite rim. The Cr-spinel compositions of the examined samples are situated tectonically in the fore-arc setting of peridotite protoliths, except for a small number of samples that exhibit boninite affinity. The observed resemblance in the Cr-spinel number content between the examined specimens and the Zagros Ophiolite peridotites suggests that the Red Beds may have originated from the Cretaceous Mawat Ophiolite Complex. The deposition of Paleocene Walash-Naopurdan rocks indicates that the lower allochthon served as a source during this process. The tectonic context of the Red Bed Series suggests that the allochthonous terranes in the Mawat region were transported and obducted onto the northeastern Arabian passive margin in the early Miocene period. The deposition of the Red Bed Series occurred concurrently with the closure of the Neo-Tethys Ocean in the&nbsp;Miocene.</p> 2024-02-23T12:34:43+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/2080 Petrography and Heavy Minerals as Tools for Provenance Identification of the Injana Sandstone (Upper Miocene), Al-Habbaniyah City, Anbar Governorate, Iraq 2024-02-29T10:09:59+00:00 Nazar Z. Al-Salmani nazarzidan1989h@gmail.com Osama J. Mohammad info@igj-iraq.org Abdulhameed Alhadaithy info@igj-iraq.org Mahmood H. Al-Kubaisi info@igj-iraq.org <p>This study deals with the petrography and heavy mineral analysis of the Injana sandstone at Al-Habbaniyah City. Thirteen samples are collected from the Injana Formation. A petrographic study is achieved on ten samples while all samples are analyzed for heavy minerals. The petrographic analysis showed that the common components of the Injana sandstone are rock fragments, especially sedimentary fragments. Quartz grains (monocrystalline and polycrystalline) and feldspars (k-feldspar and plagioclase), bounded by matrix and carbonate cement. The suggested provenance for the Injana Formation is mainly sedimentary and igneous sources and the less dominant metamorphic source. These sandstones are considered to be mineralogically submature-immature and classified as litharenites. Heavy minerals analysis showed two sets of minerals including opaque and transparent minerals, the opaque minerals are significant components of the heavy mineral assemblages, then chlorite, epidotes, amphiboles, garnet, pyroxenes (ortho and clino), zircon, tourmaline, biotite, muscovite, rutile, and others. This assemblage implies that the dense minerals are typically found in basic igneous and metamorphic rocks, with less frequent occurrences in acidic igneous and reworked sediments. According to QLF and QmFLt classifications, the tectonic provenance of the Injana sandstone is described as recycled orogen. The MF-MT-GM classification showed that the sandstone of Injana is derived primarily from active continental margins. The result of maturity MI and ZTR revealed low values of maturity, the MI value ranges between 0.6 to 1.5 with an average of 0.9 and ZTR Maturity ranges between 0.7% and 9% with an average of 3.9%, these low&nbsp;values of maturity indicate sub-mature to immature sandstone.</p> 2024-02-23T12:35:15+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/2122 Depositional Model of Early-Middle Turonian Deep Water Gulneri Formation, in Selected Outcrop and Subsurface Sections in Northern Iraq 2024-02-29T10:09:59+00:00 Mohammed A. Al-Haj mohamedalhaj@uomosul.edu.iq Irfan Sh. Asaad irfan.asaad@su.edu.krd Noor T. Al-Taee noortalal@uomosul.edu.iq Sardar M. Balaky Sardar.balaky@soran.edu.iq <p>The Gulneri Formation (Early-Middle Turonian) Deep-water depositional model was constructed using detailed microfacies analysis from the northern Iraqi wells of Kirkuk (K-116) and Bai Hassan (BH-81) as well as the Dokan outcropped area. In the outcropped section, the formation consists of 2 m of thin friable marly limestone with high organic matter and thin-bedded black shale in addition to boulder and gravel-like limestone masses in the lower part. In the K-116 and BH-81 wells, the formation is 4.3 m and 9 m thick, respectively. It is composed mainly of black bituminous, pyritic calcareous shale, and shaley limestone with scattered glauconites. Petrographic studies of seventeen thin sections of the Gulneri rocks reveal that the pelagic/deep marine faunas are the dominant skeletal grain in the micritic groundmass. Three main microfacies were recognized in the studied rocks of the Gulneri Formation, namely lime mudstone, lime wackestone, and lime packstone. However, the latter is absent in the Dokan section. According to their environmental interpretation, these microfacies were grouped into two facies associations (basinal deep water and deep shelf). Based on the results of petrographic and microfacies analyses, it is concluded that the Gulneri Formation was deposited in a basinal deep marine environment with quiet and reducing conditions in the Dokan section and a basinal deep marine environment in the K-116 and BH-81 wells which changed at intervals to a shallower deep shelf setting toward the upper part with semi reducing conditions. The euxinic deep basin that formed at the beginning of the Kurdistan foreland basin's formation was quite anoxic and deeper from the northeast to the relatively shallower basin with semi-reduced conditions towards the southwest. This is how the depositional model&nbsp;of the Gulneri Formation in northern Iraq changed.</p> 2024-02-23T12:35:50+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/2056 Construction of Regional Seismic Section Along Central Part of Iraq and its Geological Importance 2024-02-29T10:09:59+00:00 Ahmed S. Al-Banna info@igj-iraq.org Hayder H. Majeed haidargeo38@gmail.com Salar S. Al-Karadaghi info@igj-iraq.org Salah M. Shalash info@igj-iraq.org <p>&nbsp; &nbsp;A regional seismic section was constructed from fourteen local seismic lines from different surveys crossing the central part of Iraq from west to east. The seismic lines’ surveys were performed during the period 1974–1990. The length of the regional seismic section is 662.5 km. The considered seismic lines are unified to the sea level datum. The quality of seismic lines is relatively poor in the western part of the regional seismic section, but it is of good quality in the central and eastern parts. Seven reflectors were identified along the regional seismic section, corresponding to ages from the Ordovician to the Miocene. The formations are Khabour (Mid-Ordovician), Akkas (Upper Silurian), Kurra Chine (Upper Triassic), Najmah (Upper Jurassic), Mauddud (Mid-Cretaceous), Shiranish (Upper Cretaceous) and Fatha (Lower Fars) (Mid-Miocene). The Two-way times for these seismic reflectors from the west to the east are 1691 – 4000 ms, 750-4000 ms, 0-4000 ms, 208-4000 ms, 206 -3310 ms, 205 -2700 ms, and 216-2500 ms for the seven formations; starting from the oldest formation (Khabour Formation to the youngest one (Fath Formation ), respectively. The top depth values of the considered formations were defined from west to east for each formation (0-4.189) km, (0.456-4.880) km, (0.708-5.936) km, (0.802-8.5) km, (0-8.977) km, (0.5-9) km, and (1.8-9) km from the oldest to the youngest formation, respectively. The horizon generally dips towards the east. Two sedimentary basins were identified, the first in the western part of Iraq within the Paleozoic formation, while the eastern basin was within the Cenozoic and Mesozoic formations. These two basins are separated by an uplift at the central part of the regional seismic section. This uplift region was confirmed by gravity and magnetic high anomaly. Many faults were detected along the regional seismic profile. Most of these faults extend from the deeper to the shallower&nbsp;formations.&nbsp;</p> 2024-02-23T12:36:26+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/1935 CBR Mapping Prediction from 2D Resistivity Imaging Using Regression Following Archie’s Formula 2024-02-29T10:09:59+00:00 Mohamed El Basri mohamed.elbasri@is.um5.ac.ma Hasnaa Harmouzi har.hasnaa@gmail.com Lahcen El Basri info.polygeo@gmail.com Mohamed Mastere mohamed.mastere@gmail.com Ibrahim Ouchen ouchen.ibrahim@gmail.com Bouchta El Fellah elfellahbouchta@gmail.com Brahim Benzougagh benzougaghbrahim@gmail.com <p>Indirect geophysical methods are increasingly associated with direct underground methods in<br>investigating the subsurface to address environmental and geotechnical problems and reduce<br>the cost of underground studies. These methods make it possible to explore large areas with<br>acceptable precision, time, and cost. The present study combines the electrical resistivity<br>method with the California Bearing Ratio for exploring an area located west of the<br>Nouakchott port in Mauritania. The study aims firstly to verify that the thickness of the<br>backfill layer must be less than 2 m throughout the entire study area and secondly to map<br>areas with low California Bearing Ratio values (&lt;80%) indicating substandard backfill<br>compaction using 2D Electrical Resistivity Tomography imaging survey and regression. The<br>measured Electrical Resistivity values exhibit a good nonlinear regression with California<br>Bearing Ratio, following Archie's equation. A map of California Bearing Ratio variation was<br>derived from the Electrical Resistivity values, indicating the distribution and variation of soil<br>strength in the study area. The results revealed that the backfill layer did not meet the<br>standards, with approximately 35% of the total area having a California Bearing Ratio value<br>below 80%. The areas with poor compaction requiring treatment were primarily located in<br>the southern sector, followed by the middle and eastern sectors.</p> 2024-02-23T12:37:09+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/2016 Permeability Prediction Using Advanced Magnetic Resonance Tools and Hydraulic Reservoir Units Techniques for the Pliocene Sand Reservoirs, Sapphire Offshore Gas Field, Mediterranean, Egypt 2024-02-29T10:09:59+00:00 Ahmed A. Baghdadi aabaghdady12@gmail.com Abdullah M. El-Sayed Qc@canspect.com Abdel-Khalek M. El-Werr aelwerr1@yahoo.com Ali E. Farag Af7007@gmail.con <p>Permeability derived from magnetic resonance advanced logging tools was used to unlock&nbsp;the Pliocene sandstone reservoir heterogeneity. Permeability prediction from well logs is a&nbsp;significant target due to the unavailability of core data. The hydraulic flow unit approach is&nbsp;used to classify the reservoir rocks according to their porosity-permeability relationship.&nbsp;The predicted permeability is calculated using Sapphire-Dh magnetic resonance porosity&nbsp;and permeability relationship for each flow unit. Flow Zone Indicator and the quality flow<br>unit have a direct proportion relationship. For the model's verification, the predicted&nbsp;permeability is plotted against the measured resonance permeability in Sapphire-Dh as a&nbsp;reference studied well, showing highly matching results. Accordingly, the applied approach&nbsp;is implemented in the other three wells, which have neither core samples nor advanced logs&nbsp;measurements.</p> 2024-02-23T12:37:40+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/1969 The Role of Geological and Geotechnical Factors in Shale Slope Instability: Case of Landslides on Road Embankments (Tizi Ouadrene Sector-Rif Extern, Morocco) 2024-02-29T10:09:59+00:00 Amine Akoudad amine.akoudad@usmba.ac.ma Hicham El Asmi info@igj-iraq.org Mostafa El Qandil info@igj-iraq.org Ahmed Zian info@igj-iraq.org Ahmed S. Senhaji info@igj-iraq.org Sabah Zandar info@igj-iraq.org Ibrahim Darkik info@igj-iraq.org Anass Marzouki info@igj-iraq.org Kaoutar Bargach info@igj-iraq.org <p>Constructing roads in geologically unstable regions such as northern Morocco poses a major challenge. The Tizi Ouadrene sector, located in the Rif External Nappe of the Rif Belt, exemplifies a significant complexity in this issue, with a risk of landslides threatening the road embankments in this area. This study aims to characterize the frequent Cretaceous shales in the study area and analyze the landslides that have occurred on the road embankments cut into these shales. It examines the role of lithology, geometry, tectonics, human activity, and water in these landslides. The geological structure of slopes and their geometric configuration are crucial factors in determining the occurrence, distribution, and other characteristics of these landslides. Defects are controlled by the relative position of sedimentary and tectonic discontinuities, as well as the relative abundance of indurated shales compared to crushed ones. Crushed shales are susceptible to rotational slides, while the indurated ones are prone to planar and wedge sliding. The latter are mainly associated with bedding planes, particularly those oriented N65-80 with slopes facing south and SSE, as well as NW-SE and NE-SW-trending&nbsp;fractures. Hydrological, tectonic, and anthropogenic factors also contribute to the instability.</p> 2024-02-23T12:38:09+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/1662 Impact of Petrophysical and Mechanical Properties on Engineering Classification of the Facha Reservoir Rocks, Western Sirte Basin, Libya 2024-02-29T10:09:59+00:00 Bahia M. Ben Ghawar muftahgloria@gmail.com Moncef Zairi moncef.zairi@enis.rnu.tn Amal M. Naji M. Elkhoja am.elkhoja@uot.edu.ly <p>Rock identification and classification have contributed to the enhancement of drilling oil&nbsp;wells and production reservoir performance. Therefore, understanding the properties of&nbsp;reservoir rocks is a major concern in the petroleum industry. In this context, Young’s modulus&nbsp;and uniaxial compressive strength are major mechanical rock properties essential for defining&nbsp;the engineering classification and modulus ratio of rocks. However, these parameters are used&nbsp;in order to examine the impact of the petrophysical properties on mechanical strength in the&nbsp;Facha member (reservoir) of the Gir Formation in the western central of Sirte Basin, oilfields&nbsp;of central Libya. Dolomite, limestone, dolomitic limestone, and anhydrite are the main&nbsp;lithofacies rock components of this reservoir, as well as of a third member of the Gir&nbsp;Formation (Lower Eocene). Young’s modulus and uniaxial compressive strength were&nbsp;computed from sonic and bulk density well logs data from six wells in four different oil fields.&nbsp;This oil-rich reservoir has an average thickness of 104 m, an average total porosity of 16%,&nbsp;and argillaceous material content (clay) of 4%. According to the engineering classification&nbsp;chart of Deere and Miller, the Facha reservoir rocks have a very low class (E &lt; 27.5 Mpa) to&nbsp;high strength class (B ≈ 110-220 Mpa) and have a medium-to-high modulus ratio (M ≈ 200–500 and H ≈ 500). Generally, the diagenesis process, for instance dolomitization, affected&nbsp;both the strength and the modulus ratio.</p> 2024-02-23T12:38:37+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/2084 Unlocking the Mysteries of the Mishrif Formation: Seismic Data Reinterpretation and Structural Analysis for Reservoir Performance Optimization in the Garraf Oil Field, Southern Iraq 2024-02-29T10:09:59+00:00 Alaa S. Al-Rikaby alaa.awad2108p@coeng.uobaghdad.edu.iq Mohammed S. Al-jawad mjawad@coeng.uobaghdad.edu.iq <p>The seismic survey is based on the reflected wave’s inherent nature from the interface among layers, which depends on the layer's density and velocity. This is called acoustic impedance and is used to resolve the confusion associated with the stratigraphic structure of the Mishrif formations in the Garraf oil field. The seismic section of the Garraf oil field in Thi-Qar Province, south of Iraq, was analyzed and interpreted. Considering the most important petroleum accumulation reservoir in the Garraf oil field, to update the structural images of the Mishrif Formation. A seismic study of the actual amplitude reflections, temporal maps, and three-dimensional depositional models demonstrated that the Mishrif Formation generate hydrocarbon from an individual structural trap in the presence of oil. Numerous abrupt discontinuities were observed in the seismic reflectors of the reservoir units of the Mishrif Formation, suggesting either a reef or a fault. The correct probability can be shown by establishing a historical match between the reservoir model and the actual behavior of the reservoir or by running a 3D vertical seismic profile log (VSP), which is more precise than the&nbsp;seismic survey previously used to explore faults.</p> 2024-02-23T12:39:11+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/2121 Nodal Analysis of Naturally Flowing Wells in Faihaa Oil Field, Yamama Formation 2024-02-29T10:09:59+00:00 Um Albanian H. Qasim um.hamed2108m@coeng.uobaghdad.edu.iq Dhifaf J. Sadeq Dhifaf.sadeq@coeng.uobaghdad.edu.iq <p>This study focuses on the Yamama Formation, a significant carbonate reservoir in southern Iraq that is one of the most important productive reservoirs in the region. The Formation is characterized by porous limestone interspersed with thin layers of argillaceous and tight limestone. The Yamama reservoir in the Faihaa oil field is divided mainly into four units; YA, YB, YC, and YD. YA and YB units are considered to be the most important oil-bearing subunits due to their good petrophysical properties. The main objective of the study is to determine the optimum production rates of four naturally flowing wells in the Faihaa oil field using the Inflow Performance Relationship and Vertical Lifting Performance curves. The study investigates four critical parameters; tubing size, water cut, reservoir pressure, and wellhead pressure, and their impact on well performance. The study finds that wellhead pressure is the primary determinant of well performance, and deviations from the original tubing size have adverse effects on well performance. An increase in water cut beyond the recommended threshold, coupled with a reduction in reservoir pressure, results in decreasing well performance. The study underscores the importance of careful monitoring and analysis of these parameters to sustain and enhance well performance in the Faihaa oil field, providing valuable insights for well operators and petroleum engineers. The study's findings can be used to optimize well performance and increase oil production rates, with significant implications for&nbsp;the petroleum industry.</p> 2024-02-23T12:39:49+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/1957 Friction Angle Prediction of Carbonate Rocks: A Case Study, Rumaila Oil Field 2024-02-29T10:09:59+00:00 Doaa S. Mahdi 150082@uotechnology.edu.iq Ayad A. A.Alrazzaq dr.ayad.a.h@coeng.uobaghdad.edu.iq <p>Friction angle (φ) and Cohesion (C) are the most important factors to depict rock's shear&nbsp;strength. The friction angle (φ) expresses a unit of rock's capacity to endure shear stress. For&nbsp;the optimization of drilling operations, monitoring of the reservoir, and production of&nbsp;hydrocarbons, the prediction of friction angle is essential. From laboratory measurements or&nbsp;wireline logging data, this parameter can be empirically predicted. The main goal of this study&nbsp;is to develop a new correlation for predicting friction angle for carbonate formations from&nbsp;well logs using the typically accessible well log data (i.e. neutron porosity, gamma ray, bulk&nbsp;density, and sonic logs) and core data. A total of 5197 well log data points were collected&nbsp;from carbonate formation with depth interval of (1920 m to 2711 m) from Rumaila oil field.&nbsp;For all 5197 data points neutron porosity, and gamma ray logs were recorded as a function of&nbsp;depth, and the corresponding shale volume and total porosity were estimated. In addition to&nbsp;these well log data, 20 data core points with 9 different values of friction angle were collected.<br>The developed correlation's estimated friction angle has been contrasted with measured ones.&nbsp;The results show that the new correlation is able to predict the friction angle of carbonate&nbsp;rocks with high accuracy (i.e. R coefficient of the new correlation was 90% and average&nbsp;absolute error of 1.6%).Thus, we conclude that the new correltion can be used to estimate the&nbsp;friction angle for carbonate formation. The new correlation helps in providing continues&nbsp;profile for friction angle with depth and leads to reduce the cost of estimating the rock<br>strength.</p> 2024-02-23T14:01:53+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/2116 Quantitative Interpretation of the Petrophysical Properties of Selected Wells for the Mishrif Formation in Nasiriyah Oilfield, Southern Part of Iraq 2024-02-29T10:09:59+00:00 Hamid A. Alsultan info@igj-iraq.org Maha R. Manhi info@igj-iraq.org Shahad L. Abbas shahadlaith779@yahoo.com Amer J. Al-Khafaji info@igj-iraq.org <p>One of the oil field's main reservoirs is the Mishrif Formation, which is found in the Nasiriyah oilfield in the southern part of Iraq (Late Cenomanian-Early Turonian). It was one of the three oil wells selected for this study. To extract various petrophysical parameters for open wells indicated by gamma ray, density, neutron, self-potential, acoustic, and resistance, a variety of well logs were analyzed. The qualitative interpretation of the logs allowed for the identification of different types of rocks, the boundaries and thicknesses of the strata, the depths of the formation, and the zones that contained water and hydrocarbons. The quantitative interpretation, which assesses the reservoir's attributes by computing its porosity, the quantity and distribution of the shales, the levels of water and oil saturation, and other elements, that are necessary to evaluate the reservoir’s units in the research wells. The features of the study wells and the used logs were reported, to make clear how these features were distributed among the sample wells. The collected petrophysical characteristics were handled and shown as charts. There are two types of units within the Mishrif Formation: reservoir-containing CR-I, MA, CR-II, and MB. In most wells, reservoir units are made up of hard, low-porous rocks that are positioned between highly porous reservoir units. For a few wells, the MA unit had low residual and mobile hydrocarbon percentages, whereas the MB unit had large percentages, while the hard rocks had significant&nbsp;percentages of water saturation.</p> 2024-02-23T14:02:21+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/1995 Determine the Reservoir Characterization, Using Seismic Data, Well Logs, Attribute Interpretation, and Static Modelling in the Duhok Province, Kurdistan Region, Iraq 2024-02-29T10:09:59+00:00 Kakarash I. Gardi kakarashgeo@gmail.com Bakhtiar Q. Aziz info@igj-iraq.org Ezzadin N. Baban info@igj-iraq.org <p>Although the High Folded Zone in the Kurdistan Region of Iraq forms part of the Zagros-Taurus Folds and Thrust belt considered one of the potential hydrocarbon provinces, the oil fields within the zone are still lacking in geophysical exploration and scientific research. So, the rationale behind this study is the prospecting and evaluation of one of the Tertiary carbonate reservoirs at the “WN” oil field in the Duhok area by integrating the 3D seismic and well-log data. The methodology covered seismic interpretation, well logs and their relevant petrophysical analysis, attribute computation, and 3D static property modeling. The constructed reservoir maps revealed a double-plunging rollover anticlinal structure trending in the East-West direction parallel to the Taurus Mountain series. A total of nineteen minor reversal faults trending E-W to ENE-WSW dissecting the northern limb of the anticline were manually interpreted. The isopach map shows various thicknesses ranging from 160 to 330 m, averaging 245 m. The property models show the limited values of their parameters as the effective porosity is limited (0.97-23%), the secondary porosity (0.43-11.7%), permeability (0.00-238.8 mD), the water saturation (12.44-99.8%), and the clay volume (0.00-9.8%). The results of this research indicate that the horizon is a promising reservoir characteristic.&nbsp;</p> 2024-02-23T14:02:48+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/2037 Petrophysical Properties Evaluation Using Well Logging of Jeribe Formation in Mansuriya Gas Field Diyala Governorate, Eastern Iraq 2024-02-29T10:09:59+00:00 Mohammed M. Al-Mahdawi Mohammed.96.1231@gemail.com Salah A. Hussain info@igj-iraq.org <p>Al-Mansuriya gas field is regarded as one of Iraq's most important gas fields because of its good economic gas reserves. The major gas reserves of the Mansuriya field are situated in the Jeribe Formation. The present study aims to determine the petrophysical properties of the Jeribe Formation in the Mansuriya gas field by using the interpretation of different well logs for the open wells MN-1, MN-2, MN-3, and MN-4. The Jeribe Formation was divided into several reservoir units depending on the final results of CPI computer processing interpretation using the Interactive Petrophysics program (Techlog). According to the results of the CPI, the Jeribe Formation in the Mansuriya gas field was divided into seven units, which are J1, J2, J3, J4, J5, J6, and J7. Matrix definition (MID) and density-neutron cross plots indicate that the lithology of the Jeribe Formation consists of a large proportion of dolomite and limestone and a little anhydrite, also in the direction of the gas evident in the Jeribe Formation. The Gamma-ray log showed that the volume of the shale is very small in the Jeribe Formation, and the formation may be clean of shale content. The reason for this small reading is the presence of some radioactive materials in the rocks of formation. Through the readings of the RHOB and NPHI logs and the results of cutoff boundaries, we can conclude that units J1 and J6 represent non-reservoir units and can be considered a cap rock for the reservoir units, and the units J2, J3, J4, and J5 are the main reservoir units for Jeribe Formation according to CPI results and the results of high porosity in these units, as they are characterized by the porosity of up to 24% and water saturation of 40 to 60%, which makes them reservoirs of high quality. The Mn-4 well showed different results from the rest of the wells, and none of its units can be considered a reservoir due to the large water&nbsp;saturation volume.</p> 2024-02-23T14:03:19+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/1880 Geoengineering Evaluation of Dammam Formation Rocks-Bahr Al-Najaf Depression-Middle of Iraq 2024-02-29T10:09:59+00:00 Haider A.S. Al-Amar Haider_abaid73@yahoo.com <p>The Dammam Formation, a 250-meter-thick geological formation in the Bahr Al-Najaf Depression that is part of the Salman Platform, comprises re-crystallized limestone mixed with nummulite near the base. It was deposited in a shallow marine environment and extends from Al-Qaim to Samawa along the Euphrates River. The formation is part of the secondary Salman Zone of the main outstanding Stable Shelf. The engineering evaluation of the Dammam Formation in Bahr Al-Najaf depression was determined by ten samples which were chosen to represent the study area. The study includes both field and laboratory components. On the field side, data on the study region and samples were obtained. Physical, engineering, chemical, and mineralogy tests were carried out in laboratories. The total density ranges from 1.848 to 2.664 gm/cm<sup>3</sup>, the porosity value ranges from 5–20 %, while the water absorption of limestone rocks values 1-7.7 %. Engineering tests were performed, including uniaxial compressive strength, which ranges between 59 and 177 Mpa. The rocks of the Dammam Formation are suitable for the manufacture of Portland cement according to global standards, as supported by chemical&nbsp;analysis.</p> 2024-02-23T14:03:48+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/1972 The Practicality of Resistivity Method for Recognizing Vertically Distributed Anomalies Using Simulated Models 2024-02-29T10:10:00+00:00 Raad Eissa raad.m@uokerbala.edu.iq <p>In brownfield sites, two proposed shallow horizontal targets were numerically modelled to mimic variable underground conditions; these targets were sequenced vertically in a different manner. Synthetic 2D electrical resistivity datasets were generated using the RES2DMOD and then inverted by using RES2DINVx64. These targets have different lengths, one with a higher and the second with a lower resistivity value relative to the background resistivity. The effectiveness of dipole-dipole, Wenner, and Wenner-Schlumberger configurations was tested by conducting a qualitative comparison. The inverted resistivity images suggest that the target sequence has a significant effect on the configuration detectability. The high resistivity target was conveniently recognized when it overlies a low resistivity target. Dipole-dipole configuration&nbsp;showed optimum results in recognizing complicated underground conditions.</p> 2024-02-23T00:00:00+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/1915 Natural and Artificial Radionuclides Distribution in Surface Soil in Baghdad International Airport Region 2024-02-29T10:10:00+00:00 Hussian A. Hussian alzbedyhussen@gmail.com Kamal K. Ali kamal.ali@sc.uobaghdad.edu.iq <p>This is the first time that radiological assessment achieved in the Baghdad International Airport (BIA) in Iraq. Twenty-three sites were sampled from upper 5 cm of the surface soil within the BIA to be analyzed for the radioactivity of natural radionuclides Ra-226, Th-232 and K-40 and the artificial radionuclide, Cs-137 using gamma spectroscopy based on Hyper pure Germanium detector (HPGe). Ten samples out of the 23 samples were analyzed for U-238, U-235 using the Neutron Activation Analysis method. To determine the percentage of DU [DU (%)] which is calculated from the <sup>235</sup>U/<sup>238</sup>U isotope ratio. The study showed that there is a possibility of slight contamination with depleted uranium in two sites out of the 23 sites that were examined. The average activities of Ra-226, Th-232, and K-40 in the study area are within the limits of world averages, while there are evidences that new feeding of Cs-137 in the region, reaches about 19 Bq/kg, from the new global fallout after Chernobyl accident. The measured and calculated absorbed doses in the study area were within international limits and no need for farther monitoring. Annual effective dose equivalent due to resuspension of Ra-226 is estimated to be 1.0E-10Sv, and this value is negligible compared with 1 mSv permissible value for public recommended by ICRP.</p> 2024-02-23T14:04:51+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/2095 Calculating the Water Balance for Kubaisa Basin by Simulating the SWAT Model, Western Iraqi Desert 2024-02-29T10:10:00+00:00 Mahmood H. Al-Kubaisi mahmoodgeologist@uoanbar.edu.iq <p>This study aims to calculate the water balance of the Kubaisa Basin in the Western Iraqi Desert using the SWAT model. The study is based on simulating water discharges and the factors affecting them over several years (1990-2023). The geographical, climatic, and hydrological data were collected to run the model. The research results indicate that water distribution in the Kubaisa Basin was estimated during the studied period, including the quantities of surface water, groundwater, and discharges. Climatic results for the Kubaisa Basin indicated an increase in the trend line for total rainfall, temperature, humidity as a relative, and solar radiation, while the trend line retreated for wind speed for the same period. The results of the hydrological components of the basin, which were shown by the SWAT model, namely rainfall (RN-P), surface runoff (SR-Q), flow as lateral (LT-Q), flow as groundwater (GW-F), evapotranspiration as actual (ET), evapotranspiration as potential (PET), water-yield (WLD), and water that permeates past (percolates) the root zone (PEC) which are considered the main elements of the water balance, had values of 79.72mm, 3.10mm, 0.02182mm, 0.0028mm, 76.47mm, 1742.16mm, 3.12mm, and 0.00mm, respectively. This research makes important contributions to the understanding and management of water resources in the Kubaisa Basin and the Western Iraqi Desert regions and can be a basis for future research in the field of improving water sustainability in these regions.</p> 2024-02-23T14:05:20+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/2110 Biostratigraphy of Jeribe Formation in Selected Wells Mansuriyha Gas Field, Eastern Iraq 2024-02-29T10:10:00+00:00 Hamza S. Mahmood sahamza687@gmail.com Luay S. Shakir info@igj-iraq.org <p>Among the most important formations to be deposited during the Tertiary period was the Jeribe Formation. It has been investigated in two wells (Mn-1 and Mn-2) in the eastern Iraqi Dyala Government's Mansuria Oil Field. To identify fauna, 65 thin sections are examined under a microscope. Benthonic Foraminifera and limestone, occasionally dolomitized, make up its composition. There are twenty species of coralline and foraminiferan algae known to science. There were two unique biozones in the range. These biozones are the Ammonia beccria Linne Range Zone (Middle Miocene) and the Borelis melo curdica (Reichel) Range Zone (Early Miocene). The age of the formation was estimated to be Early Middle-Miocene based on these biozones of Foraminifera and other fossils such as gastropods, pelecypods, coral, fossils,&nbsp;Brayozoa, shell fragments, Echinoderm, echinoid plate, and echinoid spine.</p> 2024-02-23T14:05:49+00:00 ##submission.copyrightStatement## https://igj-iraq.org/igj/index.php/igj/article/view/2015 Geomorphology of Pramuka Cay, Kepulauan Seribu Regency, Jakarta, Indonesia 2024-02-29T10:10:00+00:00 Ahmad Cahyadi ahmad.cahyadi@ugm.ac.id Muh A. Marfai arismarfai@ugm.ac.id Tjahyo N. Adji adji_tjahyo@ugm.ac.id Indra A. Riyanto indraagusriyanto@unmaha.ac.id Dhandhun Wacano dhancano@gmail.com <p>Small islands have unique characteristics that make them highly vulnerable to environmental&nbsp;damage and disasters. A good understanding of geomorphological characteristics will greatly&nbsp;assist in understanding the potential damage to natural resources that may occur, as well as&nbsp;help in planning better environmental management and assist in more effective disaster&nbsp;mitigation in the future. This study aims to analyze geomorphological characteristics and&nbsp;identify their influence on potential environmental damage and existing geomorphological&nbsp;hazards. The analysis shows that the geomorphological characteristics of Pramuka Cay cause<br>it to have potential environmental damage and geomorphological hazards consisting of high&nbsp;vulnerability to sea level rise, water resource scarcity, seawater intrusion, groundwater&nbsp;pollution, coastal erosion and tsunami.</p> 2024-02-23T14:06:16+00:00 ##submission.copyrightStatement##