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Aspects of rare earth element geochemistry of the Pond Creek coalbed, Pike County, Kentucky Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-08-13 James C. Hower, Cortland F. Eble, Shelley D. Hopps, Tonya D. Morgan
The chemistry of rare earth elements (REE) and selected critical elements was examined in the high volatile A bituminous Pond Creek coal in Pike County, Kentucky. The Pond Creek coal has been one of the most important coal resources in eastern Kentucky but, up to now, no modern methods, such as Inductively coupled plasma – mass spectroscopy (ICP-MS) have been applied to the characterization of the
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Impact of thermal maturity on the diagenesis and porosity of lacustrine oil-prone shales: Insights from natural shale samples with thermal maturation in the oil generation window Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-08-11 Bo Liu, Yi Wang, Shansi Tian, Yuanling Guo, Liu Wang, Qamar Yasin, Jianguo Yang
Shale diagenesis controls the generation, migration and accumulation of hydrocarbons through time and has become a frontier area of study in the fields of sedimentology and petroleum geology. There have been only a few studies on the generation of organic pores in lacustrine shale oil reservoirs during the oil generation thermal evolution stage. In this study, lacustrine organic-rich shale samples
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Oil migration, retention, and differential accumulation in “sandwiched” lacustrine shale oil systems from the Chang 7 member of the Upper Triassic Yanchang Formation, Ordos Basin, China Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-08-10 Qiulei Guo, Yue Yao, Lianhua Hou, Shuheng Tang, Songqi Pan, Feng Yang
To extract hydrocarbons from unconventional shale systems, it is necessary to assess oil retention and accumulation. This study presents experimental findings on oil retention, migration, and accumulation in a lacustrine shale system from the Chang 7 member of the Upper Triassic Yanchang Formation, Ordos Basin. 68 core samples were collected from the target layer to investigate the migration behavior
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Record of Middle Jurassic wildfire and its incidental mercury emissions in northern Qaidam Basin, China: Evidence from the inertinite and mercury anomalies in coal Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-08-11 Wenquan Xie, Jingqiang Tan, Wenhui Wang, Jianliang Jia, Zhaojun Liu, Jian Wu, Yong Wang, Xueqi Song
Inertinite in coals contains important information regarding the palaeo-wildfire history and can provide insights into its triggers and relationship with the evolution of local ecosystems. However, such information in the Middle Jurassic coal is often overlooked, and the impacts of incidental mercury emission from wildfires on the mercury enrichment in coal are also underestimation. In this study,
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Corroborative insights into genetically related kerogen, asphaltenes and hydrocarbons using free and bound biomarkers Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-08-11 Shengyu Yang, Brian Horsfield, Kai Mangelsdorf, Joachim Rinna, Alexander Hartwig, Rolando di Primio, Antonio Martín-Monge, Rafael Antonio Tocco, Rouven Elias
Unlike the free biomarkers, which can be routinely recovered via solvent extraction, the bound biomarkers are covalently linked to the kerogen or asphaltene macrostructures and are more resistant to secondary alteration processes. Although similarities have been identified between these two types of biomarkers using different techniques, it remains unclear how the kerogen- and asphaltene-bound biomarkers
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Characterizing mechanical heterogeneity of coal at nano-to-micro scale using combined nanoindentation and FESEM-EDS Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-08-10 Ang Liu, Shimin Liu, Yiwei Liu, Bangzhi Liu, Ting Liu
The variations of mechanical properties of coals in nano-to-micro scale play vital roles in defining the coal deformative and failure behaviors with a wide range of engineering applications, including coal stimulation for gas recovery and/or CO2 sequestration in coal seams. Based on the assumption that the heterogeneity in the mechanical properties of coals is combinedly determined by the mineralogical/carbon
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Graptolite reflectance anomaly Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-08-03 Xiaowei Zheng, Niels H. Schovsbo, Qingyong Luo, Jia Wu, Ningning Zhong, Fariborz Goodarzi, Hamed Sanei
Thermal maturation is traditionally evaluated based on vitrinite reflectance (VRo) measurements and its relationship to oil and gas generation and diagenetic transformation are ingrained in many basin modeling tools. However, vitrinite derives from higher land plants that evolved in Devonian. In pre-Devonian rocks graptolite reflectance (GR) is the most significant thermal index for establishing thermal
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Facies development of coal seams in the Knurów deposit (Upper Silesia, Poland) Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-08-03 Piotr Sosnowski, Iwona Jelonek
This paper presents the first attempt to develop the facies model of the entire coal deposit belonging to the Carboniferous productive sequence located in the western part of the Upper Silesian Coal Basin. To achieve this objective, six seams from the Knurów deposit were examined. The deposit belongs to the largest producer of coking coal in Europe, which is Jastrzębska Spółka Węglowa SA (Polish state-run
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Decoupling experiments for CH4 “diffusion-seepage” in coal columns to effectively measure sorption time Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-08-02 Qingquan Liu, Wenyi Huang, Lv Biao, Xiaohang Ma, Xiaodong Lu, Jing Wang, Liang Wang
Sorption time is a key parameter for calculating the gas mass exchange between the matrix and the fracture system of coal, and which is generally defined as the time taken for coals to desorbed 63.2% of the total adsorbed CH4. It's usually measured through CH4 isothermal adsorption-desorption experiments with coal particles or blocks. However, the conventional method has many problems in determining
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Specific gas emissions in Bowen Basin longwall mines, Australia Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-08-02 Qingdong Qu, Rao Balusu, Bharath Belle
Longwall coal mines in the Bowen Basin of Australia are highly productive and gassy, comprising many coal seams above the working seam. Predictive modelling of specific gas emission (SGE) using the conventional Winter model developed in Germany or other European based models often results in significant discrepancies from reality. To improve methane emission prediction and management, significant efforts
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Biodegradation of early thermogenic gas and generation of secondary microbial gas in the Tieliekedong region of the northern Tarim Basin, NW China Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-08-02 Haijiao Fu, Detian Yan, Xianbo Su, Jiawei Wang, Quan Li, Xiang Li, Weizhong Zhao, Liwei Zhang, Xiaoming Wang, Yueguo Li
Some important progress has been made in coalbed gas (CBG) exploration in the Kuqa-Bay coalfield in the northern Tarim Basin, where a demonstration base of CBG development and utilization has been established in the Tieliekedong (TD) region. Currently, there has been no detailed study of the formation mechanism of the CBG in the TD region, which has restricted the next phase of the CBG exploration
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Interactions between mineral evolution and organic acids dissolved in bitumen in hybrid shale system Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-07-22 Weijiao Ma, Yingchang Cao, Kelai Xi, Keyu Liu, Miruo Lin, Jinzhong Liu
Lamina, a common lithologic unit in shale, is the smallest unit for organic–inorganic fluid–rock interactions. The effects of lamina-scale diagenetic processes are superimposed to exert on lithofacies-scale diagenetic sequences, which further impose on the entire diagenetic system of a shale reservoir. Organic acids from kerogen maturation are indispensable components in diagenetic reaction. However
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Relating systematiccompositional variability to the textural occurrence of solid bitumen in shales Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-07-26 M. Rebecca Stokes, Brett J. Valentine, Paul C. Hackley, Aaron M. Jubb
This study presents Raman spectroscopic data paired with scanning electron microscopy (SEM) images to assess solid bitumen composition as a function of solid bitumen texture and association with minerals. A series of hydrous pyrolysis experiments (1–103 days, 300–370 °C) using a low maturity (0.25% solid bitumen reflectance, BRo), high total organic carbon [(TOC), 14.0 wt%] New Albany Shale sample
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Organic matter accumulations in the Santonian-Campanian (Upper Cretaceous) lacustrine Nenjiang shale (K2n) in the Songliao Basin, NE China: Terrestrial responses to OAE3? Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-07-21 Wei Liu, Mu Liu, Tao Yang, Xin Liu, Theodore R. Them, Kun Wang, Congsheng Bian, Qi'an Meng, Yongxin Li, Xu Zeng, Wenzhi Zhao
The local and/or global environmental effects on the organic matter (OM) enrichment in ancient sediments has long received extensive attention. The Upper Cretaceous Nenjiang lacustrine shale (K2n) is one of the most essential hydrocarbon source rocks in NE China with massive OM deposition across the Santonian–Campanian boundary interval, which can be correlated with the terminal stage of the last oceanic
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Application of aromatic/aliphatic ratios analysis in revealing migration pathways in unconventional reservoirs: A case study of the Bakken Shale Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-07-25 Arash Abarghani, Omid H. Ardakani, Steven B. Hawthorne, Steven A. Smith, Bethany A. Kurz, James A. Sorensen
The ratio of aromatic to aliphatic (AR/AL) hydrocarbons was used to investigate migration pathways in tight unconventional reservoirs. Analytical methods, including organic petrography and geochemistry, programmed pyrolysis, solid bitumen reflectance, and liptinite autofluorescence, were employed to generate regional thermal maturity maps. While AR/AL ratios are known to increase with thermal maturity
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Paradigms of biomarker and PAH distributions in lower Gondwana bituminous coal lithotypes Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-07-14 Santanu Ghosh, Suryendu Dutta, Sudip Bhattacharyya, Ritam Konar, Tanu Priya
The present study aims to illustrate the paradigms of saturated and aromatic biomarker distributions in the lithotypes of Lower Gondwana bituminous coals (R̄r = 0.50–0.68%), perhaps for the first time. The coal samples were collected from the Early Permian Barakar Formation of the Rajmahal Basin, India. These coals mostly comprise three lithotypes, i.e., vitrain, durain, and fusain. The durain shows
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Geochemistry of two high-lithium content coal seams, Shanxi Province, China Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-07-08 Beilei Sun, Fangui Zeng, Tim A. Moore, Sandra Rodrigues, Chao Liu, Guoquan Wang
Prospecting for trace and rare earth elements will only increase in the coming decades as the world expands into sustainable energy and the use of digital technology. A key component of finding these resources is understanding how they are distributed, mobilized and emplaced. The coal beds in Shanxi Province in China have already been identified as a resource with elevated trace elements, especially
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Effects of confining pressure and microscale heterogeneity on hydrocarbon retention and pore evolution from artificial maturation of Eagle Ford Shale Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-06-30 Deyong Shao, Tongwei Zhang, Yanfang Li, Kitty L. Milliken, Yu Zhang, Hui Song
Although shale heterogeneity has recently emerged as a key topic in unconventional petroleum systems, hydrocarbon (HC) retention and pore evolution in organic-rich shales still remain poorly constrained. In this study, an organic-rich Eagle Ford Shale sample (EqVRo = 0.92%) from a shale-oil prospecting well in South Texas was selected for gold-tube pyrolysis experiments to investigate organic matter
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Geochemical features of altered carbonaceous mudstones from Troyanovo-3 mine borehole (Maritsa Iztok lignite field, Bulgaria) Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-06-30 Zlatka Milakovska, Maya Stefanova, Georgi Vladislavov, Stefan P. Marinov
We sampled and studied a borehole located at the southern part of Maritsa Iztok lignite field (Bulgaria) which comprises Late Miocene-Pliocene sediments of Maritsa Formation. The current report of Troyanovo-3 Mine sequence is the first to our knowledge. It represents a lignite- mudstone succession with variations in organic matter (OM) maturity. Thirty eight coal and mudstone core samples showed predictable
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The transition toward the Messinian evaporites identified by biomarker records in the organic-rich shales of the Tripoli Formation (Sicily, Italy) Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-06-22 Ádám Nádudvari, Martina Forzese, Rosanna Maniscalco, Agata Di Stefano, Magdalena Misz-Kennan, Leszek Marynowski, Tomasz Krzykawski, Bernd R.T. Simoneit
Pre-evaporitic Messinian deposits, consisting of a cyclic alternation of diatomites with lime mudstones, and laminated marls, crop out all over the Mediterranean area, representing important archives of deteriorating environmental conditions. The peculiar section of Torrente Vaccarizzo (Sicily) shows several intervals of organic-rich shales, exceptionally rich in lipid biomarkers, interbedded mostly
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Structural compartmentalization and its relationships with gas accumulation and gas production in the Zhengzhuang Field, southern Qinshui Basin Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-06-23 Dameng Liu, Yanbin Yao, Hui Wang
The Zhengzhuang Field is a new developing coalbed methane (CBM) field in the southern Qinshui Basin. To disclose the high interwell heterogeneity in production, we provide a detailed investigation of local structural controls on the gas accumulation in the Zhengzhuang Field. The Zhengzhuang Field is a northwest-dipping homocline that contains abundant normal faults, and several secondary folds, karst
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Laminae characteristics of lacustrine shales from the Paleogene Kongdian Formation in the Cangdong Sag, Bohai Bay Basin, China: Why do laminated shales have better reservoir physical properties? Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-06-22 Bixiao Xin, Xianzheng Zhao, Fang Hao, Fengming Jin, Xiugang Pu, Wenzhong Han, Qilu Xu, Pengfei Guo, Jinqiang Tian
Laminae are the most typical and representive sedimentary feature in organic-rich shales, and revealing their influences on the reservoir physical properties is vital to understand the oil enrichment mechanisms of lacustrine shale. This study investigated the laminae characteristics and their effects on the physical properties of the shales from the Second Member of the Kongdian Formation (Ek2). The
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Machine learning and data augmentation approach for identification of rare earth element potential in Indiana Coals, USA Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-06-22 Snehamoy Chatterjee, Maria Mastalerz, Agnieszka Drobniak, C. Özgen Karacan
Rare earth elements and yttrium (REYs) are critical elements and valuable commodities due to their limited availability and high demand in a wide range of applications and especially in high-technology products. The increased demand and geopolitical pressures motivate the search for alternative sources of REYs, and coal, coal waste, and coal ash are considered as new sources for these critical elements
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Maturation study of vitrinite in carbonaceous shales and coals: Insights from hydrous pyrolysis Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-06-10 Divya K. Mishra, Paul C. Hackley, Aaron M. Jubb, Margaret M. Sanders, Shailesh Agrawal, Atul K. Varma
The presence of vitrinite in sedimentary rocks of post-Silurian age allows its reflectance to be used to estimate the thermal maturation of organic matter in petroleum systems. Increasing reflectance of vitrinite, which is primarily driven by aromaticity, depends primarily on the time and temperature attributes of its evolutionary pathway. This study evaluated carbonaceous shales proximal to coal measures
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Evaluation of elemental affinities in coal using agglomerative hierarchical clustering algorithm: A case study in a thick and mineable coal seam (kM2) from Soma Basin (W. Turkey) Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-06-09 Mete Eminagaoglu, Rıza Görkem Oskay, Ali Ihsan Karayigit
The hierarchical clustering algorithm, especially Pearson correlation coefficient, along with other statistical approach, is used statistical approach for determining the toxic elements affinities in coal, and this method is one of the common approaches due to the correlations between some elements with minerals that cannot be chemically affiliated. This study aims to correlate geochemical and mineralogical
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Unsupervised contrastive learning for few-shot TOC prediction and application Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-06-09 Huijun Wang, Shuangfang Lu, Lu Qiao, Fangwen Chen, Xipeng He, Yuqiao Gao, Junwei Mei
Total organic carbon (TOC) content is significant for “sweet spots” prediction and resource calculation. Traditional physical methods and machine learning methods, however, only use labeled samples (core TOC samples and well logging data) to predict TOC, resulting in a performance bottleneck. Meanwhile, many oilfields have considerable unlabeled data (well logging data). Therefore, this paper proposed
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Non-overmature equivalents confirmed a high initial hydrocarbon generation potential of the Permian Longtan Shale in southern China Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-06-08 Ende Deng, Qian Zhang, Zhijun Jin, Rukai Zhu, Zhihua Yan, Bingren Jiang, Ralf Littke
This study presents the first organic and inorganic geochemical characterization of a non-over mature section of the Permian Longtan Shale as it can be found in the southwestern Guizhou Province, China. Compared to previous studies, the here analyzed interval lies in the oil window, which allows a more detailed and precise interpretation of the original kerogen quality, the depositional conditions
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Petrographic and geochemical characteristics of selected coal seams from the Late Cretaceous-Paleocene Guaduas Formation, Eastern Cordillera Basin, Colombia Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-06-07 Tim A. Moore, Shifeng Dai, Carme Huguet, Jillian Pearse, Jingjing Liu, Joan S. Esterle, Rongkun Jia
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Effects of acid concentration on the recovery of rare earth elements from coal fly ash Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-31 By K. Mokoena, L.S. Mokhahlane, S. Clarke
A rise in global energy demand has led to an increase in coal consumption. Consequently, global coal fly ash production has increased creating a pressing need for recycling and utilisation of coal fly ash. Since coal fly ash is enriched with rare earth elements one application is to extract rare earth elements from this waste material. There has been a rise in demand for rare earth elements over the
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Organic petrologic and geochemical characterization of petroleum source rocks in the Middle Jurassic Dameigou Formation, Qaidam Basin, northwestern China: Insights into paleo-depositional environment and organic matter accumulation Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-31 Zhongrui Wu, Sebastian Grohmann, Ralf Littke, Tianxu Guo, Sheng He, Alireza Baniasad
The organic matter-rich mudstones of the Middle Jurassic Dameigou Formation in the northern Qaidam Basin are regarded as the principal petroleum source rocks for unconventional resource exploration in China. In this study, a detailed investigation on the organic petrography, inorganic geochemistry as well as bulk and molecular organic geochemistry is presented. Three different source rock units were
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The retention of precursor biotic signatures in the organonitrogen and organooxygen compounds of immature fine-grained sedimentary rocks Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-31 Huiwen Yue, Andrea Vieth-Hillebrand, Shengyu Yang, Hans-Martin Schulz, Brian Horsfield, Stefanie Poetz
To reveal the impact of biomass input (marine algae, terrestrial plants and lacustrine Botryococcus braunii) on the composition of high molecular weight organooxygen and organonitrogen compounds (Ox, Ny and NyOx), solvent extracts of immature–early mature rock and coal samples were systematically characterized by Fourier transform ion cyclotron resonance mass spectrometry using different ionization
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Petrology, palynology, and geochemistry of the Pond Creek coal (Pennsylvanian, Duckmantian), Pike County, Kentucky: Overprints of penecontemporaneous tectonism and peat doming Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-24 James C. Hower, Cortland F. Eble
The petrographic, palynologic, and geochemical character of the high volatile A bituminous Pennsylvanian (Bashkerian, Duckmantian) Pond Creek coal was evaluated for a series of mine samples in the Lick Creek and Jamboree 7 ½’ quadrangles in Pike County, Kentucky. In its prime years of production, the Pond Creek coal was among the most important coal resources in the leading coal producing state in
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Insights into coupling between in-situ coalbed water geochemical signatures and microbial communities Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-20 Qiong Wang, Hao Xu, Dazhen Tang, Pengfei Ren
The degradation of coal into CH4 by microorganisms is a multi-stage process involving a variety of bacteria and archaea. However, little understood about the coupling between in-situ coalbed water geochemical signature and microbial communities involved in different degradation processes. Here, the relation is made between the geochemical signature of the in-situ coalbed water (pH, anions, light metal
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Hydrothermal activity in ultra-deep strata and its geological significance for deep earth gas exploration: Implications from pyrobitumen in the Ediacaran-lower Cambrian Strata, Sichuan Basin Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-25 Lianqiang Zhu, Guangdi Liu, Zezhang Song, Zhang Benjian, Wenzhi Zhao, Xingwang Tian, Kui Ma, Yunlong Wang, Dailin Yang, Qiang Li, Chao Gen, Jiaxun Lu
Abundant pyrobitumen related to an abnormal thermal event has been observed in the Ediacaran-lower Cambrian reservoirs of the central Sichuan Basin. Using reflected light microscopy, this study classified reservoir pyrobitumen in the Ediacaran-lower Cambrian into three groups: isotropic, mosaic, and fibrous; the mosaic pyrobitumen was further subdivided into fine-grained, medium-grained, and coarse-grained
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Petrology of the Parvadeh coals, Tabas Basin, Iran Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-25 R. Esmailpour, S. Alipour, F. Doulati Ardejani, S. Rodrigues, J. Esterle
The Tabas Basin is in the Tabas Block in the central part of Iran, and it contains Iran’s largest coal deposits, mostly in the Parvadeh Coalfield. The basin is structurally characterised by regional scale thrust faults and orthogonal strike-slip faults that segregate the coalfields into different areas namely Parvadeh (P) I to IV. The coals under study are in the upper Triassic Nayband Formation. Samples
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Turonian-Senonian organic-rich sedimentary strata and coal facies in Parnassos-Ghiona Unit, Central Greece: An assessment of palaeoenvironmental setting and hydrocarbon generation potential Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-24 Maria-Elli Damoulianou, Stavros Kalaitzidis, Nikolaos Pasadakis
In the past few years, scientific research related to the hydrocarbon potential in Greece has been focused on the formations of the Ionian Unit in the western areas of the country, where oil-seepages are well known. In contrast, Parnassos-Ghiona geotectonic Unit (PGU), Central Mainland Greece, has mainly been studied for the presence of bauxite ores. However, Upper-Cretaceous organic-rich strata, including
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Characterization of deposited dust and its respirable fractions in underground coal mines: Implications for oxidative potential-driving species and source apportionment Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-18 Yunfei Shangguan, Xinguo Zhuang, Xavier Querol, Baoqing Li, Natalia Moreno, Pedro Trechera, Patricia Córdoba Sola, Gaëlle Uzu, Jing Li
Oxidative potential (OP) is considered to be an efficient indicator of particulate matter (PM) to induce oxidative stress in the lungs and is increasingly considered to be a relevant health metric. In this study, two complementary OP assays were deployed, including dithiothreitol (DTT) and ascorbic acid (AA) assays, to investigate the potential toxicity (as generators of oxidative stress) of respirable
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Rare earth elements and other critical elements in the magnetic fraction of fly ash from several Polish power plants Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-14 Ewa Strzałkowska
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Evaluating aromatization of solid bitumen generated in the presence and absence of water: Implications for solid bitumen reflectance as a thermal proxy Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-13 Paul C. Hackley, Aaron M. Jubb, Patrick L. Smith, Ryan J. McAleer, Brett J. Valentine, Javin J. Hatcherian, Palma J. Botterell, Justin E. Birdwell
Geological models for petroleum generation suggest thermal conversion of oil-prone sedimentary organic matter in the presence of water promotes increased liquid saturate yield, whereas absence of water causes formation of an aromatic, cross-linked solid bitumen residue. To test the influence of hydrogen from water, organic-rich (22 wt% total organic carbon, TOC) mudrock samples from the Eocene lacustrine
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Effects of simulated surface freshwater environment on in situ microorganisms and their methanogenesis after tectonic uplift of a deep coal seam Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-07 Yueguo Li, Haijiao Fu, Detian Yan, Xianbo Su, Xiaoming Wang, Weizhong Zhao, Hu Wang, Gang Wang
Secondary biogenic coalbed gas (CBG) is the gas generated by the microbial degradation of coal or wet gas components after freshwater recharge events. However, in situ microorganisms in deep coalbed water with high total dissolved solids (TDS) content may be overlooked. The evolution of the community structure and gene function of in situ microorganisms and their contributions to secondary biogenic
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A theoretical and experimental investigation of gas adsorption-dependent bulk modulus of fractured coal Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-07 Linan Su, Adelina Lv, Mohammad Ali Aghighi, Hamid Roshan
Changes in the bulk modulus of coal induced by sorbing gases occur during gas production and CO2 sequestration processes in coal seams. Understanding these changes, however, remains a challenge due to the complexity of coupled sorptive poromechanical processes. Some studies report that the bulk modulus of fractured coal reduces with gas adsorption, others state otherwise. In this study, we perform
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Zeolite and associated mineral occurrences in high-sulphur coals from the middle Miocene upper coal seam from underground mines in the Çayirhan coalfield, (Beypazarı, Central Turkey) Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-04 Ali Ihsan Karayigit, Nevin Azeri, Rıza Görkem Oskay, James C. Hower
Three sampling profiles (BA, BB, and BC) from, respectively, the A, B, and C sectors of the Çayırhan coalfield representing the working Tv and Tb splits of the Middle Miocene-age upper seam were investigated for mineralogical and elemental compositions. The Tv and Tb splits are mainly separated by a 70–100-cm thick tuffaceous clastic rock/marl parting in the study area, and the thickness of the Tv
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Hydrological effects of the underground hydraulic curtain with different design parameters based on numerical modeling for a co-exploitation of coal and uranium Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-04 Ting Yan, Wei Wang, Li Chen, Zhenhong Wang, Yuzhe Ren
Coal is both the most widely utilized traditional energy resource and a raw material for chemical industries. Uranium is an important nuclear fuel used to produce clear electric energy. The coal mine is widely distributed, while the uranium deposit is scarce. However, a large storage of both the two ore deposits, with the uranium deposit lying above the coal seam, was found in the Tarangaole coalfield
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Deep-basin gas generation via organic–inorganic interactions: New insights from redox-controlled hydrothermal experiments at elevated temperature Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-04 Yanan Yang, Ningning Zhong, Jia Wu, Yueyang Pan
Under hot, deep-basin conditions, hydrogen-to-carbon ratios of residual kerogen are low. Whether ubiquitous water in sedimentary environments contributes hydrogen directly to hydrocarbon gas formation through organic-inorganic interactions is, therefore, critical for natural gas generation. Accordingly, we conducted laboratory experiments on immature to overmature kerogens at 300–600°C and 700 bar
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Differences and origins of hydrocarbon generation characteristics between mudstone and shale in the Seventh Member of the Yanchang Formation, Ordos Basin, China Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-05-02 Ruihui Zheng, Yifan Wang, Zhipeng Li, Zhihuan Zhang, Guangli Wang, Heng Zhang
Organic-rich black shale and dark-grey mudstone are widespread in the Seventh Member of the Yanchang Formation, Ordos Basin. There are obviously differences in geochemical characteristics and hydrocarbon generation potential between black shale and dark-grey mudstone. Based on the detailed organic geochemical examination, this paper reveals the differences in hydrocarbon generation processes and characteristics
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Deformation-related coalification: Significance for deformation within shallow crust Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-04-26 Song Yu, Jiang Bo, Veerle Vandeginste, Jonathan P. Mathews
With a low mechanical strength and high Poisson's ratio, coal can exhibit brittle or ductile deformation when exposed to lower levels of stress, strain rate, pressure, and temperature compared to the adjacent sedimentary rocks (sandstone, mudrock, and carbonate). The physical and optical properties of deformed coals have been extensively examined. However, it is still unclear if within the shallow
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Integrating advanced soft computing techniques with experimental studies for pore structure analysis of Qingshankou shale in Southern Songliao Basin, NE China Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-04-21 Bo Liu, Reza Nakhaei-Kohani, Longhui Bai, Zhigang Wen, Yifei Gao, Weichao Tian, Liang Yang, Kouqi Liu, Abdolhossein Hemmati-Sarapardeh, Mehdi Ostadhassan
Evaluating pore structure of unconventional shale reservoirs enables us to determine their productivity, allowing for better operational decisions. Despite extensive studies in this field, considering the complexity of shale plays, pore structure analysis of such formations still requires novelties and further research. In this study, 10 samples from the Qingshankou Formation (from 5 wells) were analyzed
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Organic geochemistry and petrography in Miocene coals in the Barito Basin (Tutupan Mine, Indonesia): Evidence for astronomic forcing in kerapah type peats Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-04-16 Hafidz Noor Fikri, Reinhard F. Sachsenhofer, Achim Bechtel, Doris Gross
In the Barito Basin of Borneo, there are extensive coal seams in the Miocene Warukin Formation. The net thickness of subbituminous C coal exceeds 100 m in the Tutupan mine. Three coal seams (from bottom to top: T110, T210, T300) were studied to explore the paleo-peat type and the factors controlling paleo-peat accumulation. The study is based on 93 coal and 7 non-coal samples, each representing a stratigraphic
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Pore accessibility by wettable fluids in overmature marine shales of China: Investigations from contrast-matching small-angle neutron scattering (CM-SANS) Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-04-04 Mengdi Sun, Jianjiang Wen, Zhejun Pan, Bo Liu, Tomasz P. Blach, Yeping Ji, Qinhong Hu, Bingsong Yu, Chunming Wu, Yubin Ke
The characterization of pore accessibility is essential for shale oil and gas reservoir evaluation. However, owing to the extremely low permeability and high heterogeneity of shale components, accurate nanoscale evaluation of pore accessibility remains challenging. In this study, a systematic investigation of nanoscale pore accessibility characteristics and their controlling factors was undertaken
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Source rock evaluation and fluid inclusion reconnaissance study of Carboniferous and Zechstein rocks in the northern margin of the Southern Permian Basin, onshore Denmark Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-04-02 H.I. Petersen, B. Holland, M. Olivarius
Hydrocarbon exploration onshore Denmark has been unsuccessful with no commercial discoveries. Several potential plays have been identified of which the Zechstein carbonate play relying on organic-rich Zechstein (Z2) carbonates as source rock is considered the most promising. Additional source rocks might be lower Carboniferous calcareous and carbonaceous units. This study aims at documenting Palaeozoic
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Geochemical and petrological characteristics of the Middle Jurassic organic-rich siliciclastic sediments from the central part of the Polish Basin Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-04-02 A. Zakrzewski, M. Waliczek, P. Kosakowski
Organic-rich claystones and mudstones can be very good source rocks for hydrocarbons. Middle Jurassic organic-rich siliciclastic horizons are known from the Polish Basin area, however, there are no hydrocarbon accumulations associated with these horizons. The main scientific goal of this paper is to propose why these horizons did not produce significant hydrocarbons quantities. To deal with it, we
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Lateral changes of organic matter preservation in the lacustrine Qingshankou Formation (Cretaceous Songliao Basin, NE China): Evidence for basin segmentation Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-03-30 Penglin Zhang, David Misch, Qingtao Meng, Reinhard F. Sachsenhofer, Zhaojun Liu, Jianliang Jia, Fuhong Gao, Achim Bechtel, Fei Hu
Organic matter-rich intervals in the Cretaceous succession of the large non-marine Songliao Basin in northeastern China (covered area ~ 87 × 103 km2), including the Turonian–Coniacian Qingshankou Formation (K2qn), offer unique records to study the role of global (e.g., climate, “limno-eustasy”) and regional (tectonics, basin geometry) controls on organic matter accumulation. A wealth of scientific
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Fractionation of hydrocarbons and NSO-compounds during primary oil migration revealed by high resolution mass spectrometry: Insights from oil trapped in fluid inclusions Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-03-26 Yufu Han, Mareike Noah, Volker Lüders, Sándor Körmös, Félix Schubert, Stefanie Poetz, Brian Horsfield, Kai Mangelsdorf
The composition of oil trapped in fluid inclusions (FI), occurring in mineral cements, can provide valuable insights into oil migration. Here, FI oils in a calcite vein (representing expelled fluids) and source rock (SR) extracts (representing retained bitumen) from the Hosszúhetény Calcareous Marl Formation (HCMF) in the Mecsek Mountains area of Hungary were investigated to assess how organic compounds
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Mechanism for the formation of natural fractures and their effects on shale oil accumulation in Junggar Basin, NW China Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-03-23 Chen Zhang, Dong-Dong Liu, Zhen-Xue Jiang, Yan Song, Qun Luo, Xin Wang
Despite the importance of natural fractures in shales, few techniques are currently available to examine their formation mechanism and effects on shale oil accumulation directly. The Middle Permian Lucaogou Formation in the Jimsar Sag of the Junggar Basin is a typical fractured shale. The Jimsar Sag has experienced multiple phases of tectonic movement since the Paleozoic Era, forming numerous natural
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Characteristics comparison and occurrence mode of different types of soluble organic matter in lacustrine shale in the Dongying Sag, eastern China Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-03-17 Jinyi He, Jingong Cai, Tianzhu Lei, Mingshui Song, Huimin Liu, Xuejun Wang
Soluble organic matter (SOM) in shale can be divided into free and adsorbed states. However, the characteristics and occurrence mode of different types of SOM remain unclear, which are of great significance to the unconventional oil and gas and hydrocarbon generation mechanism. This paper investigates the characteristics of different types of SOM, discusses the relationships between SOM and minerals
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The influence of Early Cretaceous paleoclimate warming event on sedimentary environment evolution and organic matter sources in Yin'e Basin: Evidence from petrology and molecular geochemistry Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-03-17 Kun Zhang, Rong Liu, Wenjing Ding, Li Li, Zhaojun Liu
The lacustrine organic-rich fine-grained sedimentary rocks of the Early Cretaceous Bayingebi Formation are widely distributed in the Yin'e Basin and they have become important source rocks for oil and gas exploration. To reveal the influence of paleoclimate warming event on sedimentary environment evolution and organic matter sources, the petrological and molecular geochemical analyses of the upper
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Origin of organic matter and organic pores in the overmature Ordovician-Silurian Wufeng-Longmaxi Shale of the Sichuan Basin, China Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-03-11 Juan Teng, Bei Liu, Maria Mastalerz, Juergen Schieber
Organic matter (OM)-hosted pores play important roles in controlling the porosity and gas content of gas shales. However, the control of organic pore development and preservation remains poorly understood, partly because of the inability to distinguish OM types under the scanning electron microscope (SEM). In this study, seven over-mature Wufeng-Longmaxi Shale samples (equivalent vitrinite reflectance
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Mineralogical and geochemical characteristics of tonsteins from the Middle Jurassic Yan'an Formation, Ordos Basin, North China Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-03-08 Zhihui Zhang, Dawei Lv, Chengshan Wang, James C. Hower, Munira Raji, Tiantian Wang, Jianqiang Zhang, Yi Yang
Although the Jurassic features a considerable accumulation of coal worldwide, only a few tonsteins within coal seams in this coal-forming period have been investigated. This paper presents the detailed mineralogical and geochemical compositions of six tonstein layers from the Middle Jurassic Yan'an Formation, Ordos Basin, North China. Based on the typical evidence of the distinct field characteristics
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Methane emissions and dynamics from adjacent coal seams in a high permeability multi-seam mining environment Int. J. Coal Geol. (IF 6.3) Pub Date : 2022-03-08 Qingdong Qu, Hua Guo, Rao Balusu
Reliable prediction of methane emission sources and dynamics from adjacent strata of longwall coal mining is critical for developing efficient methane capture designs to maximise emission reduction and improve mining safety. This paper presents an integrated field monitoring study that has resulted in many new insights into mine methane emissions and dynamics in a relatively high permeability, multi-seam