Ore and Energy Resource Geology最新文献

{"title":"Petrography and sulfur isotope geochemistry of middle Miocene evaporites on the active continental margin, Ras Banas Peninsula, Red Sea coast, Egypt","authors":"Kamal Abou Elmagd ,&nbsp;Ryo Matsumoto ,&nbsp;Mohamed Abioui ,&nbsp;Muhammad Hazem","doi":"10.1016/j.oreoa.2025.100119","DOIUrl":"10.1016/j.oreoa.2025.100119","url":null,"abstract":"<div><div>The present study aims to investigate the paleoenvironmental conditions and relative sea-level change during the middle Miocene evaporite deposition at the Ras Banas Peninsula, Red Sea Coast, Egypt. The tectono-sedimentological evolution of the evaporite suite may provide a geological relationship with the surrounding structures of the peninsula. To address this objective, the study examines the petrology and sulfur isotope geochemistry of the middle Miocene sulfate evaporites (approximately 100 meters in thickness) of the Abu Dabbab Formation at the Ras Banas Peninsula, located along the Red Sea continental margin. The Abu Dabbab Formation can be subdivided into three distinct sedimentary facies, from base to top: (1) lower supratidal gypsiferous claystone, (2) middle lagoonal sandy and clayey gypsum, and (3) upper subaqueous marine laminated gypsum. Petrographic analysis reveals the presence of both primary and secondary evaporite facies, with the mineralogical composition dominated by gypsum, alongside minor amounts of anhydrite and dolomite. Geochemical data indicate that the average sulfur isotopic compositions (δ³⁴S) for the lower, middle, and upper facies are 23.62⁰/₀₀, 23.30⁰/₀₀, and 23.83 ⁰/₀₀ VCDT, respectively. These findings suggest that the Abu Dabbab evaporites were deposited in a tectonically active basin that received inputs of meteoric water and fine clastics, influenced by seasonal shifts between arid and wet conditions. The occurrence of stratabound mineralization and isotopically light sulfur suggests that algal biological activity played a role in reducing sulfate to iron sulfide and native sulfur. The rapid lateral and vertical facies changes observed in this active continental margin are primarily attributed to tectonic processes and the associated paleoenvironmental dynamics.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100119"},"PeriodicalIF":0.0,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145219202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrokinetic removal of Cd, Ti, Pb, and Sb from abandoned and active artisanal gold tailings from Amansie West District of Ghana","authors":"Timothy Amangdam Anemana ,&nbsp;Ernest Pankah ,&nbsp;Mohammed Moro Buri","doi":"10.1016/j.oreoa.2025.100118","DOIUrl":"10.1016/j.oreoa.2025.100118","url":null,"abstract":"<div><div>This study explores the effectiveness of electrokinetic removal of heavy metals, such as Cd, Ti, Sb, and Pb from abandoned and active tailing soils among different soil fractions/phases. owing to the nature of the soil components in tailings, traditional methods may encounter various challenges that are ineffective. The aim of the study is to understand and address the distribution of heavy metals among tailing soil fractions (exchangeable, carbon, iron manganese oxide, organic/sulfide, and residual bound fractions) via electrokinetic remediation. The research was conducted in a 1215 cm³ electrochemical cell containing gold tailings via a continuous constant current of 1 A for five days. A platinum electrode served as the anode, and a titanium plate acted as the cathode. After five days, the remediation efficiency was assessed via aqua regia and sequential extraction methods. The findings showed lower metal removal efficiencies of the abandoned tailings (&lt;5 %) than those of active tailing soil. This phenomenon could be attributed to the surface charge of the soil particles and the diffusion of metals into soil minerals resulting in the stabilization and occlusion of the the heavy metals into the nonavailable phases of the soil (organic/sulfide and residual bound fractions). In the speciation studies, Pb species were enriched mainly in the residual fraction. Antimony was also enriched in the residual, organic/sulfide bound, and Fe/Mn fractions. The Cd was associated with organic/sulfide and residual fractions, whereas Ti was enriched mainly in organic/sulphide fractions. The concentration of heavy metals in the active and abandoned tailing soils were comparable. The study concluded that electrokinetic remediation has the potential to remove harmful elements from abandoned and active tailings whiles providing insightful information on the physicochemical phenomena governing these processes.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100118"},"PeriodicalIF":0.0,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145157117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical characteristics of Upper Cretaceous asphaltenes from bitumen seeps in the Kurdistan region, northern Iraq: Insights from trace metals and Fourier Transform Infrared (FTIR) spectroscopy","authors":"Edris Muhammed Pirot ,&nbsp;Ayad Nuri Faqi Edilbi ,&nbsp;Mahdi Mohammed Pirot Mamash ,&nbsp;Bzhar Abdulmanaf Delizy ,&nbsp;Sardar Mhyadin Balaky ,&nbsp;Nabaz Abdulmajed Muhammad Salih ,&nbsp;Hossein Khojasteh","doi":"10.1016/j.oreoa.2025.100117","DOIUrl":"10.1016/j.oreoa.2025.100117","url":null,"abstract":"<div><div>Fourier Transform Infrared Spectroscopy (FTIR) and trace metal analysis were conducted on the set of 20 solid bitumen samples obtained from two geological formations; upper Campanian – lower Maastrichtian Bekhme Formation and Maastrichtian Aqra Formation. This study analyzes the infrared (IR) spectra of extracted asphaltene samples of both studied formations from two regions in northern Iraq (Bekhme region and Sare Sada region), focusing on key functional groups and molecular vibrations. The spectra reveal consistent peaks for alcohols (O<img>H stretching), alkyl groups (CH₂ and CH₃ bending), and unsaturated bonds (alkenes and alkynes) across all studied samples. Additional peaks indicate the presence of C<img>O stretching (suggesting alcohols and ethers) and metal-carbon stretching, pointing to metal coordination. The analysis highlights the complex structure of asphaltenes, which combine aliphatic chains, aromatic components, and trace metals. Peak intensities reflect slight similarities in composition. The stretching phenomenon can be attributed to the stretching vibration of hydroxyl groups. Comparing the aromatic, aliphatic, and long chains, together with the nickle to vanadium ratio, indicates that the examined samples originated from the same source of organic matter. Furthermore, it is highly probable that all samples from both studied regions originated from a mixed marine-terrestrial-oxic-dysoxic carbonate environment.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100117"},"PeriodicalIF":0.0,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145094914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alteration mapping in granitic gneiss using handheld geophysical and geochemical instruments: Implications for iron oxide-apatite and rare earth elements exploration","authors":"Kaitlyn A. Suarez ,&nbsp;Michael L. Williams ,&nbsp;Gregory J. Walsh ,&nbsp;Daniel E. Harlov ,&nbsp;Michael J. Jercinovic ,&nbsp;Daniel J. Tjapkes ,&nbsp;Ian W. Hillenbrand","doi":"10.1016/j.oreoa.2025.100116","DOIUrl":"10.1016/j.oreoa.2025.100116","url":null,"abstract":"<div><div>The Adirondack Mountains of New York, U.S.A. contain iron oxide-apatite (IOA) mineral deposits with variable concentrations of rare earth elements (REE). The IOA mineral deposits are typically hosted in the Lyon Mountain Granite Gneiss and are spatially correlated with extensive Na metasomatism (albitization) of the surrounding country rocks, although some mineral deposits also occur in metagabbro, paragneiss, and anorthosite hosts. The location of albitization zones is key to finding new IOA mineral deposits and better understanding the mineralization processes associated with their genesis. However, the Na alteration zones are generally not visibly identifiable in outcrop or hand specimens because the color and textural changes are subtle and are thus difficult to map. Here, we discuss the results from testing two spectroscopic techniques (handheld, field gamma-ray spectroscopy, and portable X-ray fluorescence (pXRF)) to characterize albitization zones surrounding IOA mineral deposits.</div><div>The gamma-ray and pXRF spectrometers successfully distinguished the relative intensity of alteration in the Lyon Mountain Granite Gneiss based on the K abundance. The measured K content decreases towards the IOA mineral deposits, and the magnitude and width of the gradient are similar along the strike of each mineral deposit. Elevated Th and U values are present in host rocks adjacent to REE-bearing IOA mineral deposits. The pXRF and gamma-ray spectrometer K values are remarkably consistent with laboratory-based, whole-rock XRF compositional data and, therefore, useful for semi-quantitative analysis. Notably, albitization aureoles are consistent around REE-rich and REE-poor mineral deposits, suggesting that saline fluids are essential for the petrogenesis of IOA mineral deposits but may not be critical to REE mineralization. Ultimately, this study demonstrates the utility of handheld gamma-ray and pXRF spectrometry for identifying otherwise cryptic albitization gradients associated with IOA mineral deposits in granitic gneiss.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100116"},"PeriodicalIF":0.0,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mineralogy and geochemistry of nephrite from Drosh area, district Chitral, northern Pakistan","authors":"Aamir Khan ,&nbsp;Mohammad Tahir Shah ,&nbsp;Liaqat Ali ,&nbsp;Shah Fahad Alam ,&nbsp;Ihtisham Islam ,&nbsp;Salman Ahmed Khattak","doi":"10.1016/j.oreoa.2025.100115","DOIUrl":"10.1016/j.oreoa.2025.100115","url":null,"abstract":"<div><div>This study evaluates the quality of nephrite by investigating its gemological, mineralogical and geochemical properties. Petrographic analysis revealed that the nephrite is primarily composed of tremolite, with minor amounts of actinolite, while the host rock, serpentinite, is predominantly composed of chrysotile and antigorite, with traces of tremolite, diopside, zoisite, talc, and plagioclase. Geochemically, the major oxides such as SiO₂, MgO, CaO and Fe₂O₃ are ranging from 54.69 to 59.1 wt. %, 20.18 to 21.89 wt. %, 10.24 to 13.98 wt. % and 2.09 to 3.01 wt. %, respectively. The trace elements, including cobalt (Co), chromium (Cr) and nickel (Ni) are ranging from 6 to 31 ppm, 401 to 1005 ppm and 789 to 987 ppm, respectively. The Fe²⁺/(Mg²⁺ + Fe²⁺) ratios for the bulk rock range from 0.10 to 0.14. Gemologically, the nephrite exhibits a color range from light-green to green, a refractive index from 1.61 to 1.62, specific gravity from 2.97 to 3.04, a hardness from 5.8 to 6.2, and Schmidt hammer values from 38.00 to 39.60 MPa. These properties are consistent with typical nephrite characteristics. The intensity of light to dark green color is controlled by variations in the contents of Fe, Cr and Ni. Additionally, the Fe²⁺/(Mg²⁺ + Fe²⁺) ratio, along with high contents of Ni and Cr, and field observations suggest that the nephrite is of serpentinite-related origin, having undergone hydrothermal metasomatic transformation through elemental exchange between the silica-rich intrusions and host ultramafic rocks. The findings of this study contribute valuable insights into the geological processes of nephrite formation, which may aid in the exploration and research of nephrite deposits in other regions.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100115"},"PeriodicalIF":0.0,"publicationDate":"2025-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144932121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linking mineralogical, geochemical, and textural controls to petrophysical signatures in the Kiruna Mining District, Sweden","authors":"Ervin Veress ,&nbsp;Oskar Rydman ,&nbsp;Rayhan A. Farrenzo ,&nbsp;Joel B.H. Andersson ,&nbsp;Mathis Warlo ,&nbsp;Irvine R. Annesley ,&nbsp;Tobias E. Bauer","doi":"10.1016/j.oreoa.2025.100114","DOIUrl":"10.1016/j.oreoa.2025.100114","url":null,"abstract":"<div><div>Discoveries of deposits at shallow depths are becoming scarce, leading exploration efforts to increasingly focus on deeper targets. Traditional exploration techniques for subsurface mapping are often ineffective in terrains obscured by vegetation and glacial sediments, prompting the development of new methods, particularly those centered on geophysics. While geophysical surveys can be valuable for peering beneath the surface cover, reducing initial exploration costs, they are often insufficient to resolve the three-dimensional architecture in structurally complex settings. Integrating geological and geophysical studies ensures that geological characteristics of rock units and structural frameworks are considered, leading to geologically validated results. Merging geological and geophysical models demands a strong understanding of how physical properties are distributed and influenced by geological factors. Our study aims to enhance the understanding of geological factors controlling petrophysical properties in the Kiruna Mining District (Sweden). We conducted an integrated analysis of geochemistry, mineralogy, texture, and petrophysical properties from 35 outcrop locations, including 105 density, magnetic susceptibility, and P-wave velocity measurements from the Kiruna area. The results reveal not only distinct contrasts between lithological units but also significant intraformational variability driven by alteration and fabric, which can obscure lithological boundaries in geophysical surveys. Structural processes such as crustal shortening and basin inversion were found to impose a strong control on the petrophysical properties, contributing to complex and diagnostic signatures. The geological-petrophysical framework presented in this study serves as a foundation for integrated studies in northern Sweden, enabling geophysical methods to serve as a tool for understanding mineral system components and test conceptual models.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100114"},"PeriodicalIF":0.0,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrographic characterization of organic matter and solid bitumen from the Pimenteiras Formation (Devonian), Parnaíba Basin (Brazil), potential for hydrocarbon generation","authors":"Agostinho Mussa,&nbsp;Wolfgang Kalkreuth,&nbsp;Ana Maria Pimentel Mizusaki,&nbsp;Marleny Blanco González,&nbsp;Tais Freitas da Silva","doi":"10.1016/j.oreoa.2025.100113","DOIUrl":"10.1016/j.oreoa.2025.100113","url":null,"abstract":"<div><div>The Paleozoic-Mesozoic Parnaiba Basin is an intraplate volcano-sedimentary basin which the Pimenteiras Formation (Devonian) has the higher potential for hydrocarbon generation, mainly gas and condensate. The present study aims to make a petrographic characterization of organic matter and solid bitumen from the Pimenteiras Formation (Devonian), Parnaíba Basin (Brazil), potential for hydrocarbon generation. The study observed the presence of solid bitumen, formed as a result of the cracking of terrestrial organic matter (gas-prone) and marine organic matter (oil-prone) during diagenesis and catagenesis. These solid bitumens were classified according to the reflectance values such as glance pitch, grahamite and epi-impsonite. The solid bitumens were observed in all analyzed wells with a significance variation in terms of thermal maturity from top to bottom of the Pimenteiras sequence. High reflectance values (epi-impsonite) were observed in samples located at the bottom of the sequence in relation to the top samples, mainly in the BP-77 well. On the other hand, significance variations in terms of vitrinite reflectance values were not observed in samples close to igneous intrusions. Greater presence of macerals such as vitrinite and inertinite was identified, and rarely were observed liptinites. Large particles of solid bitumens were observed, being mostly biostructured and characterized by a homogeneous gray surface, mostly well preserved and isotropic. Similar biostructuring was also observed in palynofacies data, through the phytocasts. The solid bitumen reflectance ranges from 0.46 to 1.16 %R_o in the BP-77 well samples, with vitrinite reflectance equivalent (VRE_o) ranging from 0.68 to 1.12 %R_o, from 0.33 to 0.50 %R_o (with VRE_o varying from 0.60 to 0.71 %R_o) in the BP-59 well samples, and between 0.36 and 0.7 %R_o with VRE_o varying between 0.62 and 0.84 %R_o in the BP-22 well samples, respectively. These data suggest that the organic matter ranges from early to late mature in terms of thermal maturity. On the other hand, the solid bitumen versus vitrinite reflectance, and solid bitumen versus T_max suggest that the OM (organic matter) varies from immature to early mature. The presence of solid bitumens suggests a thermal maturity of the organic matter and potential for hydrocarbon generation.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100113"},"PeriodicalIF":0.0,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the hydrocarbon potential of source rocks in Northern Borneo, Southeast Asia: a review of organic geochemical and petrological characteristics","authors":"Ayodele O. Falade ,&nbsp;Yousif M. Makeen ,&nbsp;Habeeb A. Ayinla ,&nbsp;Abayomi A. Edema","doi":"10.1016/j.oreoa.2025.100112","DOIUrl":"10.1016/j.oreoa.2025.100112","url":null,"abstract":"<div><div>This study provides a comprehensive review of hydrocarbon source rocks in Northern Borneo by integrating findings from previous organic geochemical and petrological studies across the Sabah, Sarawak, and Brunei basins. Unlike earlier basin-specific research, this work offers a broader regional perspective, evaluating sixteen (16) formations ranging from Late Cretaceous to Pleistocene. The majority of the samples exhibit good to excellent organic richness (mean total organic carbon (TOC) content exceeding 1 wt%, with promising S₂ and S₂/S₃ ratios). The hydrogen index (HI) values (7.1 and 401.8 mg HC/g TOC) and HI vs. Oxygen Index (OI) plots indicate that the organic matter is primarily composed of Type II/III, Type III and Type IV kerogen. Remarkably, coal-related samples consistently show excellent organic richness, predominantly plotting within the Type II/III kerogen area, indicating a strong potential for mixed oil and gas generation. Other lithologies primarily contain gas-prone Type III kerogen, while Type IV is largely inert. The thermal maturity assessments, based on T_max (324–570 °C) and production index (PI) (0.00–0.37), indicate a wide range from immature to overmature source rocks. Vitrinite reflectance (VR_o) measurements (0.15–3.10 %) and T_max vs VR_o plots further confirm these maturity trends. The organic petrological analysis reveals that the vitrinite macerals dominate the liptinite and inertinite across all the formations, with coal-related source rocks exhibiting the highest maceral concentrations, reinforcing their generative capacity. Specifically, the coal-rich Nyalau, Tanjong, Liang, Batu Arang, Balingian, and Bergih formations stand out as highly promising, presenting substantial economic significance for unconventional plays such as coalbed methane (CBM). This review highlights the significant hydrocarbon potential across Northern Borneo, while also emphasizing the need for further assessment of the Brunei Basin to refine the current understanding of source rock distribution and quality within the regional petroleum system.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100112"},"PeriodicalIF":0.0,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of CO₂ treatment on fracture development and mineralogical composition in organic-rich and organic-lean unconventional reservoirs","authors":"Israa S. Abu-Mahfouz ,&nbsp;Ahmed Al-Yaseri","doi":"10.1016/j.oreoa.2025.100111","DOIUrl":"10.1016/j.oreoa.2025.100111","url":null,"abstract":"<div><div>Fracturing associated with carbon dioxide (CO₂) treatment in unconventional hydrocarbon reservoirs presents a huge potential for CO₂ geological sequestration in carbonate mudrock and shale reservoirs and the use of CO₂ as a working fluid for oil recovery. This study aims to examine the impact of CO₂ treatment on fracture growth and propagation in unconventional carbonate reservoirs. Experimental studies were conducted on both organic-rich (Jordanian) and organic-lean (Wolf Camp) mudrock samples and a careful examination of fracture initiation and propagation induced by CO₂ treatment was examined. After an extensive 30-day treatment with carbonate brine (i.e., a mixture of brine and CO₂) under 75 °C temperature and 4158 psi pressure, mineralogical and geochemical results revealed an increase in the carbonate mineral content (calcite) in the organic-rich sample, along with a decline in total organic carbon content from after CO₂/carbonate brine treatment. The organic-lean sample, inversely, showed negligible change in the calcite content and almost no change in the total inorganic carbon. Microscopic investigations showed that the organic-rich sample exhibited a remarkable development of a new set of horizontal (bedding-parallel) microfractures, while the organic-lean sample did not display any significant fracture development. In addition, the surface roughness of the organic-rich sample increased significantly (from 20 to 37 uµ on average), after carbonate brine treatment, while the organic-lean sample showed a slight increase from 18 to 19 uµ. The outcomes of this study will be used to develop a comprehensive understanding of the mechanisms driving the fracture growth and propagation in organic-rich unconventional reservoirs induced by CO₂ treatment, which can inform strategies to enhance oil/gas recovery. They will also aid in defining the potential benefits of CO₂-induced fracturing for underground CO₂ storage, such as improving the permeability and porosity of unconventional rock formations, and for oil recovery, such as enhancing the recovery factor.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100111"},"PeriodicalIF":0.0,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144858282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comprehensive review of advanced polymer gel technologies in enhanced oil recovery and water production control","authors":"Amir Javad Borhani,&nbsp;Fatemeh Ghazi,&nbsp;Ali Akbari,&nbsp;Ali Ranjbar,&nbsp;Yousef Kazemzadeh","doi":"10.1016/j.oreoa.2025.100109","DOIUrl":"10.1016/j.oreoa.2025.100109","url":null,"abstract":"<div><div>Excessive water production is a major challenge in the petroleum industry, significantly reducing oil recovery efficiency and increasing operational costs by approximately $50 billion annually. Enhanced Oil Recovery (EOR) methods, such as thermal and non-thermal techniques, aim to improve oil production by altering reservoir and fluid properties. Thermal methods, including steam injection and electromagnetic heating (EMH), have shown oil production increases ranging from 11 % to 500 %, despite high initial costs and operational complexities. Non-thermal methods, such as polymer, surfactant, and alkaline injections, target light to medium viscosity oils, achieving oil recovery improvements between 5 % to 45 %. Chemical methods, particularly polymer gels, have gained prominence for their efficacy in controlling excessive water production and enhancing oil recovery. Polyacrylamide gels, known for their profile control capabilities, can increase oil recovery by 10–30 %. Recent advancements in microgels and nanogels offer better stability and compatibility with harsh reservoir conditions, such as high salinity and temperatures, resulting in recovery improvements up to 35 %. Field studies demonstrate the USA and Canada leading in EOR adoption, with polymer injection projects constituting over 80 % of chemical EOR applications. To further advance oil recovery and address excessive water production, continued research into optimizing polymer gel formulations and exploring new chemical EOR methods is essential. Tailoring EOR techniques to specific reservoir conditions, including temperature, salinity, and rock permeability, will enhance their effectiveness. The integration of nanoparticles into polymer gels shows promise for improving structural strength and performance, highlighting the need for innovative approaches in the petroleum industry.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"19 ","pages":"Article 100109"},"PeriodicalIF":0.0,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144738660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}