Palaeoenvironmental evolution of formation of Bayanjargalan oil shale: evidence from trace elements and biomarkers

AbstractThe genetic type of the Bayanerhet Formation oil shale in the Bayanjargalan mine area is an inland lacustrine oil shale deposit. Inorganic element analysis and organic geochemical testing of oil shale samples collected in three boreholes show that the Bayanerhet Formation oil shale has relatively high organic contents, e.g., average TOC values of 6.53, 7.32 and 8.84 (corresponding to oil contents of 5.49%, 6.07% and 7.50%) in boreholes BJ3807, BJ3405 and BJ3005, respectively. Analysis of organic matter sources with biomarkers indicates that lower aquatic organisms such as algae contribute more to the organic matter than higher plants do. According to research on the values of Fe2O3/FeO, Rb/Sr and w (La) n/w (Yb)n in cores from the three boreholes, the Bayanjargalan oil shale is inferred to have formed in a humid paleoclimate with a relatively high sedimentation rate. In research on the evolution of the paleoaquifer in which the oil shale formed, the values of Fe3+/Fe2+, V/V + Ni, Ni/V, Ceanom and δCe are applied as sensitive indicators of the redox conditions in the aqueous medium. These values indicate that the Bayanjargalan oil shale formed in a water body with a weak redox environment. Moreover, the values of Ca/(Ca + Fe) and Sr/Ba and the values of gammacerane/αβC30 hopane in biomarkers show that the oil shale was formed in a saltwater environment. Analysis of Mo and U shows high endogenous lake productivity, corresponding to high TOC, which suggests that the lacustrine productivity played an important role in organic matter enrichment. The Lower Cretaceous Bayanerhet Formation (K1bt) in the Bayanjargalan mine area encompasses a complete sequence and was formed during lowstand, transgression, highstand and regression periods. The dominant oil shale deposits were formed in the transgression system tract and high stand system tract, and these oil shales have a high oil content and stable occurrence. A large set of thick, high-TOC and high-oil-content oil shales in the second member of the Bayanerhet Formation was deposited under such conditions. The abundant terrigenous supply under warm and humid conditions significantly promoted the primitive biological productivity, and the weak redox saltwater environment had relatively high productivity. All the favorable conditions promoted the formation of high-quality oil shale.

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ORGANIC MATTER IN OIL SHALES

The APPEA Journal ◽

10.1071/aj79005 ◽

1980 ◽

Vol 20 (1) ◽

pp. 44 ◽

Cited By ~ 17

Author(s):

A.C. Hutton ◽

A.J. Kantsler ◽

A.C. Cook ◽

D.M. McKirdy

Keyword(s):

Organic Matter ◽

Oil Shale ◽

Large Scale ◽

Mineral Matter ◽

Green River ◽

Fine Grained ◽

Recovery Cost ◽

Oil Shales

The Tertiary oil-shale deposits at Rundle in Queensland and of the Green River Formation in the western USA, together with Mesozoic deposits such as those at Julia Creek in Queensland, offer prospects of competitive recovery cost through the use of large-scale mining methods or the use of in situ processing.A framework for the classification of oil shales is proposed, based on the origin and properties of the organic matter. The organic matter in most Palaeozoic oil shales is dominantly large, discretely occurring algal bodies, referred to as alginite A. However, Tertiary oil shales of northeastern Australia are chiefly composed of numerous very thin laminae of organic matter cryptically-interbedded with mineral matter. Because the present maceral nomenclature does not adequately encompass the morphological and optical properties of most organic matter in oil shales, it is proposed to use the term alginite B for finely lamellar alginite, and the term lamosites (laminated oil shales) for oil shales which contain alginite B as their dominant organic constituent. In the Julia Creek oil shale the organic matter is very fine-grained and contains some alginite B but has a higher content of alginite A and accordingly is assigned to a suite of oil shales of mixed origin.Petrological and chemical techniques are both useful in identifying the nature and diversity of organic matter in oil shales and in assessing the environments in which they were formed. Such an understanding is necessary to develop exploration concepts for oil shales.

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Application of a scanning electron microscope for differentiation of organic matter in oil shales and of oil shale kerogens.

BUNSEKI KAGAKU ◽

10.2116/bunsekikagaku.37.10_530 ◽

1988 ◽

Vol 37 (10) ◽

pp. 530-537

Author(s):

Mariko ISHIWATARI ◽

Haru SAKASHITA ◽

Takashi TATSUMI ◽

Koichi ADACHI ◽

Mitushiro ADACHI ◽

...

Keyword(s):

Organic Matter ◽

Electron Microscope ◽

Scanning Electron Microscope ◽

Oil Shale ◽

Oil Shales ◽

Scanning Electron

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XIII.—A Chemical Examination of the Organic Matter in Oil-Shales

Proceedings of the Royal Society of Edinburgh ◽

10.1017/s0370164600013341 ◽

1914 ◽

Vol 34 ◽

pp. 190-201 ◽

Cited By ~ 1

Author(s):

John B. Robertson

Keyword(s):

Organic Matter ◽

Microscopic Examination ◽

Oil Shale ◽

The Other ◽

Chemical Examination ◽

Chemical Action ◽

Orange Yellow ◽

Other Hand ◽

Bacterial Action ◽

Oil Shales

Investigations into the nature of the organic matter in oil-shales began at the time of the famous Torbanehill case in 1854, when experts attempted to settle the question as to whether the substance known as “ Torbanite ” or “ Boghead Mineral” was a coal or an oil-shale. Several witnesses at the trial (Gillespie v. Russel, Session Papers, 1854) maintained that the oilproducing material in the Mineral was of organic origin, while others pronounced it to be bituminous and produced by subaqueous eruptions. T. S. Traill, M.D., proposed for the Boghead Mineral the name “ Bitumenite,” as it seemed to him to “ consist of much bitumen, mingled with earthy matter” (Trans. Roy. 8oc. Edin., 1857, xxi. p. 7). Dr Redfern (Quart. Jonrn. Micros. Soc, 1855, x. pp. 118-119), on the other hand, supposed the round orange-yellow bodies which occur in torbanite to have had their origin in "“ a mass of vegetable cells and tissues which have been disintegrated and otherwise changed by maceration, pressure, and chemical action, and subsequently solidified."” C. E. Bertrand and B. Renault (Bull. Soc. Hist. Nat. Autun, 1892-3) on microscopic examination have classed these bodies as the remains of gelatinous algae which have been altered by bacterial action.

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Comparison of Geochemical and Mineralogical Characteristics of Palaeogene Oil Shales and Coals from the Huangxian Basin, Shandong Province, East China

Minerals ◽

10.3390/min10060496 ◽

2020 ◽

Vol 10 (6) ◽

pp. 496

Author(s):

Xue Zheng ◽

Baruch Spiro ◽

Zuozhen Han

Keyword(s):

Organic Matter ◽

Oil Shale ◽

Shandong Province ◽

Depositional Environments ◽

East China ◽

High Concentration ◽

Volcanic Origin ◽

Depositional Processes ◽

Mineralogical Characteristics ◽

Oil Shales

Coal and oil shale are both organic matter-rich sedimentary rocks. However, their sources of organic matter and their depositional environments are different. The present study focuses on the Palaeogene Lijiaya Formation sequence in the Huangxian Basin, Shandong Province, East China, which has oil shales showing marine geochemical indicators overlain by coals indicating marine regression. We investigated the C1 coal seam and underlying OS2 oil shale layers, compared their geochemical and mineralogical characteristics, clarified the details of their constituents, in order to elucidate the features of their sources, their depositional environments, and the post depositional processes in the context of the geological evolution of the basin. The Al2O3/TiO2 (18.1–64.9) and TiO2/Zr ratios (28.2–66.5) in the C1 coals and OS2 oil shales, respectively, suggest a felsic to intermediate source, and the Mesozoic granite on the South of Huangxian Fault may be one of the provenances of these sediments. The low sulphur content (0.53–0.59%) and low Sr/Ba ratios (0.32–0.67) suggest a freshwater depositional environment for the C1 coals. In contrast, the higher total sulphur contents (0.60–1.44%), the higher Sr/Ba ratios (0.31–1.11%), and the occurrence of calcareous shells, indicate seawater intrusions during deposition of the oil shales. The V/Ni, V/(V + Ni), and V/Cr ratios of the OS2 oil shale suggest oxic to suboxic conditions with a distinct change in palaeo-redox between the lower and upper parts of OS2 seam. The high boron contents in C1 coals (average, 504 ppm) is related to the high content of analcime (with the correlation coefficient of 0.96), and the high concentration of boron was attributed to a secondary enrichment by epigenetic hydrothermal solutions. The occurrence of idiomorphic-authigenic albite in association with analcime and quartz in veins in the coals suggests that albite is a product of a reaction between analcime and silica, both of volcanic origin. The reaction takes place at about 190 °C, indicating that the area was affected by hydrothermal fluids.

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Structural Characteristics of Low-Aromaticity Marine and Lacustrine Oil Shales and their NaOH-HCl Kerogens Determined Using 13C NMR and XPS

Australian Journal of Chemistry ◽

10.1071/ch20168 ◽

2020 ◽

Vol 73 (12) ◽

pp. 1237

Author(s):

Mohammad W. Amer ◽

Jameel S. Aljariri Alhesan ◽

Thomas Gengenbach ◽

Marc Marshall ◽

Yi Fei ◽

...

Keyword(s):

Organic Matter ◽

Elemental Analysis ◽

13C Nmr ◽

Photoelectron Spectroscopy ◽

Oil Shale ◽

Structural Characteristics ◽

Average Chain Length ◽

Near Surface ◽

Organic C ◽

Oil Shales

Few comparisons have been made between low-aromaticity marine and lacustrine oil shales and their kerogens, because the reliability of structural analyses has been limited by a reliance on only one method of kerogen isolation, HCl-HF. Therefore, a detailed analysis by 13C NMR and X-ray photoelectron spectroscopy (XPS) was made for Attrat marine oil shale (Jordan) and Colorado (Green River) lacustrine oil shale (USA) and their NaOH-HCl kerogens. Some differences between oil shales and their kerogens were noted, but many structural features were considered to be true characteristics of the organic matter. The results emphasise the importance of comparing the analyses of kerogens isolated by different methods to ensure that features of the organic matter are not an artefact of the method of kerogen isolation. For both oil shales, the predominantly aliphatic character of the organic part was confirmed and the long average chain length of the aliphatic hydrocarbons was established. All shales and their kerogens showed a small cluster size for the aromatic rings. The elemental analysis obtained by XPS, compared with the bulk elemental analysis, indicated major differences between the near-surface region sampled by XPS and the bulk. The organic S was determined to be aliphatic and aromatic S with possibly small amounts of sulfoxide. Most of the N was pyrrolic with smaller amounts in pyridinic or quaternary form. Nearly all of the surface organic C in both kerogens was bonded to C and H. Two major forms of organic O were distinguishable. A good correlation between the proportion of aliphatic S and pyrolysis reactivity is suggested.

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Comprehensive Spectral and Thermal Characterization of Oil Shales

10.2118/spe-172952-ms ◽

2015 ◽

Author(s):

S.. Guven ◽

S.. Akin ◽

B.. Hascakir

Keyword(s):

Organic Matter ◽

Oil Shale ◽

Thermal Characterization ◽

Organic Content ◽

Depositional Environments ◽

Gravimetric Analysis ◽

Dsc Analysis ◽

Reserve Estimation ◽

Oil Shales

Abstract The heterogeneous nature of oil shale resources associated to the depositional environments, lithology, and organic content make the reserve estimation complex and unpredictable. However, comprehensive laboratory studies on organic rich shale samples collected from different regions can increase the understanding about the organic content of oil shales, interaction of shale with organic matter and injected fluid used during enhanced oil recovery method. This study investigates the characterization of eight different Turkish and American oil shale samples with several spectral methods and a thermal analysis. The main purpose of this study is to characterize the oil shale samples to increase the understanding about the organic content and interaction of shale with organic matter. In this study, we used Thermal Gravimetric Analysis/Differential Scanning Calorimetry (TGA/DSC) analysis to estimate organic content of each oil shale sample in air and nitrogen environments. X-Ray Diffraction (XRD) was used to define minerals in oil shale. Fourier Transform Infrared Spectroscopy (FTIR) was used to detect the mineral and kerogen in oil shale before and after the TGA/DSC analysis. Scanning Electron Microscope (SEM) was used to characterize the depositional environment of each oil shale samples. TGA/DSC results verified that oil shale samples have up to 50% of organic matter. XRD and FTIR results helped to identify the organic and inorganic compounds. Effects of minerals and ions were recognized by comparing TGA/DSC curves and FTIR spectra. It was recognized that the more carbonate ion in the oil shale the more increase in weight loss occurred. Diatoms identified from SEM results showed that depositional environments of the some oil shale samples are marine environments. This study provides insight for the reserve estimation of the eight different oil shale samples with comprehensive spectral and thermal characterization.

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Biomarkers geochemistry of the Alpagut oil shale sequence: an evaluation of dispositional environments and source rock potential from Dodurga-Çorum basin (N-Turkey)

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01450-5 ◽

2022 ◽

Author(s):

S. Korkmaz ◽

R. Kara-Gülbay ◽

T. Khoitiyn ◽

M. S. Erdoğan

Keyword(s):

Organic Matter ◽

Source Rock ◽

Oil Shale ◽

Sedimentary Environment ◽

Organic Matter Content ◽

Type I ◽

Terrestrial Organic Matter ◽

High Hydrogen ◽

Oil Shales ◽

Biomarker Data

AbstractThe Cenozoic Çankırı-Çorum basin, with sedimentary facies of varying thickness and distribution, contains raw matters such as coal deposits, oil shales and evaporate. Source rock and sedimentary environment characteristics of the oil shale sequence have been evaluated. The studied oil shales have high organic matter content (from 2.97 to 15.14%) and show excellent source rock characteristics. Oil shales are represented by very high hydrogen index (532–892 mg HC/g TOC) and low oxygen index (8–44 mgCO2/g TOC) values. Pyrolysis data indicate that oil shales contain predominantly Type I and little Type II kerogen. The biomarker data reveal the presence of algal, bacterial organic matter and terrestrial organic matter with high lipid content. These findings show that organic matters in the oil shales can generate hydrocarbon, especially oil. High C26/C25, C24/C23 and low C22/C21 tricyclic terpane, C31R/C30 hopane and DBT/P ratios indicate that the studied oil shales were deposited in a lacustrine environment, and very low Pr/Ph ratio is indicative of anoxic character for the depositional environment. Tmax values from the pyrolysis analysis are in the range of 418–443 °C, and production index ranges from 0.01 to 0.08. On the gas chromatography, high Pr/nC17 and Ph/nC18 ratios and CPI values significantly exceeding 1 were determined. Very low 22S/(22S + 22R) homohopane, 20S/(20S + 20R) sterane, diasterane/sterane and Ts/(Ts + Tm) ratios were calculated from the biomarker data. Results of all these analyses indicate that Alpagut oil shales have not yet matured and have not entered the oil generation window.

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Three-Phase Segmentation Method for Organic Matter Recognition in Source Rocks via CT Images: A Case Study On Oil Shale Pyrolyzed by Steam

Energy & Fuels ◽

10.1021/acs.energyfuels.1c00917 ◽

2021 ◽

Author(s):

Xudong Huang ◽

Dong Yang ◽

Zhiqin Kang

Keyword(s):

Organic Matter ◽

Oil Shale ◽

Ct Images ◽

Source Rocks ◽

Segmentation Method ◽

Three Phase

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The mechanical behavior of the Kettle Point oil shale

Canadian Geotechnical Journal ◽

10.1139/t86-011 ◽

1986 ◽

Vol 23 (1) ◽

pp. 87-93 ◽

Cited By ~ 4

Author(s):

Maurice B. Dusseault ◽

Matthias Loftsson ◽

David Russell

Keyword(s):

Oil Shale ◽

Clay Content ◽

Organic Content ◽

Point Load ◽

Brazilian Test ◽

Point Load Strength ◽

Triaxial Strength ◽

Deformation Properties ◽

Strength And Deformation ◽

Oil Shales

Samples of eastern black shale (Kettle Point oil shales, Ontario) were subjected to extensive mineralogical and geomechanical tests. We prove that the mineralogy, as measured by the ratio of quartz to illite, controls strength and deformation properties, and the organic material plays no significant role. The reason is that increasing clay content dilutes the rigid quartz–quartz grain contacts that are responsible for the high strengths and stiff behavior. Tests of temperature effects on point load strength of another low organic content oil shale confirm that organic matter is not important to mechanical properties in matrix-supported shales. Key words: shale, mineralogy, Brazilian test, triaxial strength, organic content, slake durability, thermogravimetry.

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