Ore and Energy Resource Geology最新文献

{"title":"Lead and Barium strata-bound deposits in eocene carbonate ramps of Iran: Implications for the influence of sedimentary environment characteristics on the distribution of Ore reserves","authors":"Hadi Veysi ,&nbsp;Saeid Jamshidi Taghabi ,&nbsp;Meysam Babaiy ,&nbsp;Mehdi Tafazoli","doi":"10.1016/j.oreoa.2024.100073","DOIUrl":"10.1016/j.oreoa.2024.100073","url":null,"abstract":"<div><div>In the case of ore deposits that are formed in marine environments, including kuroko deposits, the effect of paleo-sedimentary environment parameters and microfacies changes is very important, but it is often neglected in economic geological research. These factors determine the dispersion and concentration of ore horizons in an ore deposit area, and recognition them leads us to the localization of high concentration ore horizons.</div><div>In this regard, lead and barite ore deposit area in the southeastern of Tafresh city (the border of Markazi and Qom provinces, Iran) was investigated. This ore deposit is of the kuroko type and is of the early to middle Eocene epoch (Ypresian-Lutetian ages) and was formed in a relatively deep ancient carbonate ramp. Investigating the concentration of different minerals and ore minerals in the mentioned ore deposit area using by remote sensing techniques indicates that the distribution of minerals and ore minerals is non-uniform with a noteworthy correlation unto the carbonate ramp microfacies in the southeastern of Tafresh. The scrutiny of microfacies characteristics and paleo-sedimentary environment showed that the distance from hydrothermal smokers, the action of different seawaves, sedimentological changes, structural features and initial morphology of microfacies have a remarkable impressiveness in the dispersion of ore reserves and the formation of horizons with a high concentration of ore.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"18 ","pages":"Article 100073"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833848","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":"Multispectral remote sensing expression of lineaments and alteration minerals in part of crystalline rock units of Southwestern Nigeria: Implication on gold prospecting","authors":"Kazeem Oladimeji Olomo ,&nbsp;Muriana Zaid Mohammed ,&nbsp;Oluwatoyin Khadijat Olomo ,&nbsp;Omowumi Ademila ,&nbsp;Marvelous Ayomide Dadamu","doi":"10.1016/j.oreoa.2025.100091","DOIUrl":"10.1016/j.oreoa.2025.100091","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The Ilesha schist belt, the location of the research area, comprises one of Nigeria's most notable schist belts, which has attracted attention due to its considerable mineral resources, including gold deposits. Recent studies in the region have emphasized aerogeophysical mapping of geological features and the implication this has for mineral potential. However, various types of alteration and their relationships with gold deposits in the region have not received proper consideration. This research is aimed at identifying specific type of hydrothermal alteration associated with existing gold deposits in the study area as a reference to establishing new prospective zones and producing mineral prospect map of the area. To achieve this, Landsat Enhanced Thematic Mapper plus (Landsat-7 ETM+), and Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER) data were utilized to define the association of lineaments and propylitic, phyllic, and argillic alteration types with Gold deposit within the study area. The processing of Landsat-7 ETM+ data were aided by applying Band ratio procedure and Principal Component Analysis (PCA). The validation was carried out using the active mining site of the study area, X-ray diffraction (XRD) analysis of some rock samples and electrical resistivity method. The results were integrated to provide information on lineaments, alteration minerals, and different types of hydrothermal alteration within the study area. Processed Landsat-7 ETM+ data delineated the structural elements as lineaments synonymous to lithologic contacts and faults/fracture zones, trending NE–SW direction, most probably controlling the alteration zones formation, distribution and localization of mineral in the country rocks of the belt. The Band ratio procedure and Principal Component Analysis (PCA) also showed that the area is rich in alteration minerals, particularly ferrous, ferric and clay minerals. ASTER multispectral analysis gave an imprint of the key alteration types within the study area, with phyllic alterations being noticeably the major alteration type associated with Gold deposits, and poses the highest prospective zone for Gold occurrence in the study area. Validation of the observed lineament dense areas with Vertical Electrical Sounding (VES) revealed highly fracture zones, thereby validating the structural framework of the study area. Also, spatial analysis involving percentage correlation evaluation carried out to compute the spatial connection between gold locations and altered zones showed that gold mine pits strongly matched with mapped altered zones with 85 percent correlation. Lastly, mineral compositions of the altered zones were confirmed by X-ray diffraction (XRD) analysis of the analyzed samples collected within the area. The research helped in understanding the spatial distribution of gold mineralisation within the study area. It is recommended that exploitation efforts be expanded to the delineated ","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"18 ","pages":"Article 100091"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512368","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":"Geological and biostratigraphical factors in hydrocarbon recovery optimization using integrated seismic, petrophysical, and core data, Niger Delta","authors":"Samuel Obomheile Salufu ,&nbsp;Kesyton Oyamenda Ozegin ,&nbsp;Charles Chibueze Ugbor ,&nbsp;Sunday O. Isehunwa ,&nbsp;Emmanuel O. Salufu ,&nbsp;Daniel Osezua Aikhuele","doi":"10.1016/j.oreoa.2024.100069","DOIUrl":"10.1016/j.oreoa.2024.100069","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The study of geologic heterogeneities (the quality of reservoir rock according to its spatial variation in properties such as grain size, mineralogy, organic content, fossil content, and natural fracture) and their impact on recovery factors, optimization, and performance of injection fluids in concurrent development (production of both oil and gas at the same time) of oil rim reservoirs (reservoirs with a thin oil column that is overlain with a large gas cap) has become necessary to explore the role of geological and biostratigraphical heterogeneity in optimizing hydrocarbon recovery from oil rim reservoirs in the Niger Delta using integrated seismic, petrophysical, and core data. This is to achieve optimum hydrocarbon recovery instead of relying only on development strategies, which is usually the practice and thus fails. Petrel and Eclipse software were used to simulate the static and dynamic models, respectively, for three oil rim reservoirs, using data (seismic, petrophysical, core, and reservoir data) from a green field in the Niger Delta, Nigeria, for concurrent development under the natural depletion (base case), surfactant enhanced-water-alternating-gas (SeWAG), and water-alternating-gas (WAG) injection options. In each option, two scenarios of injection well positions were simulated: gas-oil contact (GOC) and oil-water contact (OWC). Geological studies showed that Reservoir 1 is a heterolith facies of lower-shoreface deposits with traces of Ophiomorpha burrows, Reservoir 2 is a channel facies of lower shoreface deposits with Ophiomorpha burrows, and Reservoir 3 is a heterolith facies of upper shoreface without vertical burrows. When SeWAG of ratio 1:4:2 was injected at OWC, the highest oil recovery factor was observed compared to other options, and injection at GOC gave the highest gas recovery factor. Permeability anisotropy (Kv/Kh) for reservoirs 1 and 2, with Ophiomorpha burrows being considered, was 0.32 and 0.34, respectively. High recovery factors for both oil and gas were recorded. However, the model of the same reservoir without Ophiomorpha burrows gave reduced values of Kv/Kh of 0.12 and 0.15, respectively, with reduced recovery factors. Reservoir 3, which doesn't have burrows in the initial model, has a Kv/Kh value of 0.11 with low recovery factors in various development cases. However, when Ophiomorpha burrows were integrated into the model, Kv/Kh was 0.31, and the recovery factors increased significantly. The study has shown that geological and biostratigraphical interactions induce Kv/Kh. It has a significant optimization impact on recovery factors in concurrent development and enhances vertical sweep efficiency in EOR (Enhanced Oil Recovery). The study further shows that &lt;em&gt;Ophiomorpha&lt;/em&gt; burrows improve the geologic heterogeneity quality of a reservoir (permeability anisotropy) by enhancing the injection fluid to get into micro- and macropore spaces for efficient sweeping of oil and gas into the development w","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"18 ","pages":"Article 100069"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834019","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":"Production indication curve of fracture-cave units in carbonate reservoirs","authors":"Yuanyuan Tian ,&nbsp;Changhui Yan ,&nbsp;Hong Cheng ,&nbsp;Jing Xue ,&nbsp;Xindan Zhou","doi":"10.1016/j.oreoa.2024.100078","DOIUrl":"10.1016/j.oreoa.2024.100078","url":null,"abstract":"<div><div>Determining the production performance of fracture-cave carbonate reservoirs is difficult because of the heterogeneous properties of these reservoirs and various production performance levels. Also, data series such as formation pressure and conductivity of fractures are hard to obtain. Thus, common methods, such as the IPR (inflow performance relationship) and water flooding curves, are often ineffective for analyzing of carbonate reservoirs. We propose a new method to analyze the production performance of fracture-cave carbonate reservoirs based on a fracture-cave model delineated by well log and seismic interpretation data, referred to as, the production indication curve. In essence, the production indication curve represents the relationship between flowing bottomhole pressure and accumulated liquid rate, and recoverable reserves can be estimated via the equation of the production indication curve. And it was validated by experiment method which revealed that recoverable reserves calculated by production indication equation was credible. With the production indication curve, recoverable reserve of typical well was estimated, and the results revealed that the proposed production indication curve technique is a dependable method for the characterization of the production performance of fracture-cave carbonate reservoirs.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"18 ","pages":"Article 100078"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mapping iron oxides with Landsat-8/OLI imagery from iron ore deposit in Singhbhum craton, eastern India: Its implication to mineral exploration","authors":"Arvind Chandra Pandey ,&nbsp;Sagar Kumar Swain ,&nbsp;Chandra Shekhar Dwivedi","doi":"10.1016/j.oreoa.2025.100089","DOIUrl":"10.1016/j.oreoa.2025.100089","url":null,"abstract":"<div><div>This research mainly focused on the Kiriburu-Meghahataburu-Bolani iron ore deposit (KMBIOD) in the Singhbhum craton, eastern India, with over 150 million tons of iron ore reserves. By applying Landsat-8/OLI multispectral remote sensing techniques, including band ratio analysis, principal component analysis (PCA), and spectral angle mapper (SAM) classification, the research effectively mapped various types of iron ores. This study employed RGB band combinations of band ratios {4(0.64–0.67 μm)/2(0.45–0.51 μm), 5(0.85–0.88 μm)/7(2.11–2.29 μm), 5(0.85–0.88 μm)/4(0.64–0.67 μm)} and PCA (PC bands 1, 5, and 6; PC bands 4, 5, and 6). These techniques were used to effectively distinguish iron ore from associated lithological units. Specific band ratios (5/7, 4/5, and 4 + 6/5) were instrumental in identifying high-grade and low-grade iron ore zones. PCA was used to provide detailed spectral information, identifying various iron ore types, including low-grade iron ore and clay minerals. The results were validated with spectral analysis and spectral angle mapper (SAM) classification methods, supported by X-ray Diffraction (XRD) analysis of iron ore samples collected during field survey. This integrated remote sensing approach proved effective for mapping iron ore in densely vegetated areas and enhancing geological understanding of mineralized zones. Landsat-8/OLI imagery demonstrated robust performance in iron ore exploration, concluding that these techniques were effective for discriminating and classifying iron ore in the Singhbhum craton and could be applied to similar regions.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"18 ","pages":"Article 100089"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534475","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":"The origin and migration mechanism of natural gas in the Yacheng Gas Field, Qiongdongnan Basin, South China Sea: Constraints from noble gas isotopes","authors":"Zefan Bai ,&nbsp;Shuyi Dong ,&nbsp;Yuhe Fan ,&nbsp;Ben Dong ,&nbsp;Feng Zheng ,&nbsp;Yingchun Wang ,&nbsp;Rongcai Song","doi":"10.1016/j.oreoa.2025.100094","DOIUrl":"10.1016/j.oreoa.2025.100094","url":null,"abstract":"<div><div>The Qiongdongnan Basin, located on the northern continental shelf of the South China Sea, is a prominent hydrocarbon-rich region. Among its core gas fields, the Yacheng Gas Field has drawn significant attention due to its complex tectonic framework and substantial natural gas reserves. However, the mechanisms governing the phase behavior (gas or liquid) and migration of natural gas in deep strata remain poorly understood and require further investigation. This study employs advanced mass spectrometry to analyze natural gas and noble gas components sampled from the Sanya and Lingshui formations in the Yacheng Gas Field. By integrating carbon isotope ratio measurements, noble gas isotopic analyzes, and PHREEQC-based solubility modeling, the research investigates the origin, migration mechanisms, and interactions of natural gas with subsurface fluid systems in this region. The results reveal that natural gas in the Yacheng Gas Field primarily originates from a mixed crust-mantle source and is closely associated with the basin's groundwater system, particularly through significant vertical interactions with formation water. In deep strata, natural gas predominantly migrates in the gaseous phase, with solubility decreasing progressively with depth.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"18 ","pages":"Article 100094"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molybdenum fertility indicators, granite zircon chemistry, and U-Pb geochronology of the Manjo pluton, southwestern Cameroon","authors":"Ngambu Aloysius Afahnwie ,&nbsp;Ralain Bryan Ngatcha ,&nbsp;Gus Nono Kouankap Djibril ,&nbsp;Cheo Emmanuel Suh","doi":"10.1016/j.oreoa.2024.100074","DOIUrl":"10.1016/j.oreoa.2024.100074","url":null,"abstract":"<div><div>Due to an increasing interest in mineral prospection, Manjo granites which are orogenic have been studied in terms of the geochemistry of whole rock and isotopes of interest found in the associated zircons. This was done to define and situate these rock unit within the context of the regional belt that is Pan African in age, establish the source of Manjo granites and their evolution during the Pan-African orogeny. More so, this study sheds more light on the controversy around the orogenic statues of granites in this section of the geological region, examines their potential for hosting molybdenum, establishes their link with other rocks within this part of the region and how they relate to the Mo-U-bearing biotite-granite in its Ekomedion neighborhood. Sixty-six zircon grains gotten from the granites and their trace elements and Lu-Hf isotopic signatures were examined. The zircon grains' ages were gotten by mass spectrometric method using the U-Pb systematics by laser ablation.The zircons ratios of U to Th varry between 0.2–2.3 relating to sources that are originally magmatic and totally different from those related to souces related to hydrothermalism and metamorphism. The granites were emplaced within the 585±17–616±12 Ma age bracket. Zircons in this study similar to the nearby Ekomedion U-Mo-bearing two mica granites and other felsic massifs found within the shear zones of central Africa (CASC)point to the fact that the Manjo granites were formed at low oxygen fugacity (log ƒO₂; -15.848 to -4.515, and log ƒO₂@FMQ; -17.409 to -3.677). More so, samples plot mainly outside the defined fertile fields on plots of Eu/Eu* Vs (Ce/Nd)/Y, 10000 × (Eu/Eu*)/Y Vs (Ce/Nd)/Y and Eu/Eu* Vs Dy/Yb. The above points support dominantly plagioclase fractionation in a reduced and less hydrous melt system pointing to a low Mo fertility potential of this pluton emplaced at an average Ti-in-zircon temperature of 861± 56°C. The apparent εHf(<em>t</em>) values for CMR-01 zircon grains range between -15.84 and -1.45 and apparent εHf_(t) values for CMR-02 zircon grains vary from -25.02 to -12.39. On spidergraphs, the grainites are depleted in HREE and enriched in LREE . These plots together with εHf_(t) values and other indications point to the fact that the granites were derived through partial melting of quartzo-feldspathic crustal magmatic sources. More so, the data showing a new age here show clear signs of post collisional Pan-African magmatism at ∼ 585±17 Ma in the context of a pre-drift Gondwana evolution.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"18 ","pages":"Article 100074"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833893","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":"Comparative analysis of Na+ and Ca2+ ion effects on the physical-chemical properties of Bentonite: Implications for industrial applications","authors":"Hanane Ait Hmeid ,&nbsp;Mustapha Akodad ,&nbsp;Mouhssin El Halim ,&nbsp;Fatima Ezzahra Omdi ,&nbsp;Mourad Baghour ,&nbsp;Ali Skalli ,&nbsp;Chaouki Sadik ,&nbsp;Hicham Gueddari ,&nbsp;Mohamed Chahban ,&nbsp;Yassine El Yousfi ,&nbsp;Mohamed Abioui ,&nbsp;Lahcen Daoudi","doi":"10.1016/j.oreoa.2025.100095","DOIUrl":"10.1016/j.oreoa.2025.100095","url":null,"abstract":"<div><div>This study investigates the potential industrial applications of two types of bentonite - Calcium Bentonite (Ca-B) and Sodium Bentonite (Na-B) <strong>-</strong> from the Kert Basin in northern Morocco. The bentonite samples' structural characteristics, inclusions, and microcracks were examined using scanning electron microscopy. X-ray diffraction analysis of both the whole rock and clay fractions was conducted to determine the bentonite type and mineralogical composition. The chemical composition was assessed through X-ray fluorescence<strong>.</strong> The physico-chemical properties analyzed included cation exchange capacity, swelling index, colloidality index, water content, and pH. The plasticity index and liquid limit were determined using Atterberg limits tests. The results indicate that sodium bentonite exhibits superior absorption and plasticity compared to calcium bentonite, with a higher cation exchange capacity, particularly after activation. The analyzed bentonites contain high amounts of iron and silica, with moderate levels of calcium and aluminum. Quartz, feldspars, and clay minerals were identified in all samples, with smectite being the dominant clay mineral phase (80 %), along with traces of kaolinite, illite, and interstratified illite-smectite. These bentonites generally display high plasticity, making them well-suited for hydraulic drilling applications. Additionally, their low organic matter and calcium carbonate (CaCO₃) content may indicate mechanical strength, water sensitivity, and purity.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"18 ","pages":"Article 100095"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611304","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":"Advances in estimations of number of undiscovered mineral deposits in three-part assessments","authors":"Donald A. Singer","doi":"10.1016/j.oreoa.2024.100077","DOIUrl":"10.1016/j.oreoa.2024.100077","url":null,"abstract":"<div><div>A central part of three-part mineral assessments is estimating number of undiscovered mineral deposits. Internal consistency and well-explored deposits in grade–tonnage models reduce chances of biased estimates in three-part quantitative assessments. Estimates are of specific types of deposit permitted by geology in delineated tracts. Regardless of estimation method, each deposit type needs a grade–tonnage model constructed with well-explored deposits and estimated numbers must be consistent with this model. Local well-explored deposits are typed and statistically tested to ensure the global grade and tonnage model is representative of them.</div><div>Three-part assessments used expert judgements since 1975 that relied on analogy-based guidelines to aid in estimation of number. The advantage of expert judgements is that they can use all available information and adapt to information supplied by other experts during the assessment. A targeting method has seen limited application due to the requirement that location indicators of each possible target need to be present. Another estimation method developed around 2008 is a generalized deposit density model based on multiple deposit types which uses deposit type's median tonnage, permissive tract area, and number of known deposits in well-explored control areas. It is remarkably robust and can be applied to any deposit type in a proper permissive tract.</div><div>Advanced deposit estimations use the generalized density method to guide expert estimates. Experts can then identify possibly flawed estimates and improve estimates based on local information such as local exploration results or observations by experts thereby further reducing chances of biased estimates.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"18 ","pages":"Article 100077"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833849","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":"Integrated geomechanical analysis of shear failure wellbore instability in abnormal and normal pore pressure zones using diverse input data: A case study","authors":"Masoud Ziaie ,&nbsp;Amirhossein Takmili ,&nbsp;Saeid Sadeghnejad ,&nbsp;Mehdi Hakimzadeh","doi":"10.1016/j.oreoa.2025.100093","DOIUrl":"10.1016/j.oreoa.2025.100093","url":null,"abstract":"<div><div>The analysis of data obtained from previous drilled wells play a crucial role in enhancing the operational safety and reducing drilling expenses. A pivotal aspect of this lies in employing a geomechanical model, offering valuable insights into predicting pore pressure, ensuring borehole stability, and optimizing casing placement. This study centers on developing an integrated geomechanical model for three wells within an oil field, especially focusing on pore pressure variations in two distinct formations. An abnormal pressure is observed at overburden zone, while the reservoir zone is characterized by a normal pressure behavior. All relevant data sources including full set logs, dipole shear sonic imager reports, image logs, drilling operation data, and leak of tests are combined as an input to the geomechanical model. The main purpose of this study is to examine the geomechanical behavior of rocks within both abnormal and normal pore pressure zones. Identification of breakout points is achieved through image logs and caliper log data, which results in providing the direction of the minimum horizontal stress. Subsequently, the entire geomechanical model undergoes adjustment and validation based on these identified points. Moreover, the calibration of minimum horizontal stress is accomplished by analyzing the leak of test data. The main finding of this study indicates that the direction of the horizontal stresses varies across different points of the reservoir. Based on the results of the image log interpretation, the minimum horizontal stress direction in well#1 is 145°, in well #2, 125°, and in well# 3, 115°. Moreover, the presence of abnormal pore pressure results in a shift in the stress regime from a normal to strike slip or reverse stress regimes. In Well#1 conforms to a strike-slip regime with wellbore stable azimuths at 30, 70, 210, and 250°. Well#2 and Well#3 exhibit a reversed regime. The well's most stable state aligning with the azimuth of maximum horizontal stress. Lastly, it is determined that the Mogi-Coulomb and the modified Lade failure criterion exhibit superior accuracy in identifying shear failure of rocks when compared to the Mohr-Coulomb criterion. By integrating diverse input data and employing comprehensive validation methods, our model emerges as a robust tool for understanding and predicting geomechanical instability in drilling operations.</div></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"18 ","pages":"Article 100093"},"PeriodicalIF":0.0,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620683","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}