oil shales
Recently Published Documents


TOTAL DOCUMENTS

799
(FIVE YEARS 63)

H-INDEX

38
(FIVE YEARS 3)

Author(s):  
S. Korkmaz ◽  
R. Kara-Gülbay ◽  
T. Khoitiyn ◽  
M. S. Erdoğan

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.


Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7191
Author(s):  
Jianliang Jia ◽  
Zhaojun Liu

The synchronous variation and association of organic matter (OM) and minerals in the hydrocarbon-generated process of oil shales are poorly understood. The goal of the paper is to investigate OM occurrence and thermal variation so as to reveal the hydrocarbon generation potential of oil shales. Based on detailed analyses of particle, organic, mineral, and thermal data from lacustrine oil shales in the Songliao Basin, we observed three layers of shale particles after settling in the water column characterized by a distinct color, degree of consolidation, and particle size. The particle sizes are divided into three ranges of fine grain (<1 μm), medium grain (1–20 μm), and coarse grain (>20 μm) via laser particle analysis. The particle-size distribution indicates the presence of OM polymerization and dominant contribution of the associated mineral surface and bioclastic OMs to the OM abundance of oil shale. Various OM occurrences are influenced by OM sources and redox conditions, whereas the degree of biodecomposition and particle sizes affect the placement of OM occurrences. Based on multiple thermal analyses, a synchronous response of OM and minerals to thermal variation dominates at 300–550 °C. The I/S and chlorite minerals are characterized by an entire illitization, while solid/absorbed OMs and hydrocarbon-generated water were expelled in large quantities. This contributes to major loss weights of oil shales during heating. The peak hydrocarbon-generated rate occurred at 457 °C for oil shales, corresponding to around 1.3% vitrinite reflectance value. These results are suggested to improve the understanding of OM occurrences and the thermal degradation constraint on the hydrocarbon-generated process, and contribute to the interpretation of the hydrocarbon generation potential and in-situ exploitation of oil shales.


2021 ◽  
pp. 178999
Author(s):  
Patrice Portugau ◽  
Martín Torres ◽  
Luis Yermán ◽  
Andrés Cuña ◽  
Jorge Castiglioni

2021 ◽  
Vol 155 ◽  
pp. 105023
Author(s):  
Jameel S. Aljariri Alhesan ◽  
Mohammad W. Amer ◽  
Marc Marshall ◽  
W. Roy Jackson ◽  
Yi Fei ◽  
...  

2021 ◽  
pp. 138707
Author(s):  
El.Hassan Chafyq ◽  
Khadija Legrouri ◽  
Mohamed Aghrouch ◽  
Mina Oumam ◽  
Said Mansouri ◽  
...  
Keyword(s):  

2021 ◽  
pp. 4-7
Author(s):  
M.Ya. Aghamammadova ◽  

Petroleum sediments in Azerbaijan have been researched and described by now in the form of complexes. Not only oil and gas deposits, but also the fields and accumulations of bitumen, bituminized rocks and oil shales are associated with these sediments. Furthermore, there are iodine, brom, the components of natural soda and so on in the oil, oil products and sediments as well. Alongside with it, a great amount of valuable metals present in the content of oil, produced water, bitumen and oil shales as an addition. This circumstance dictates the necessity of formation division of oil sediments. There are ten oil formations: Upper Pliocene-Lower Pleistocene, oil bearing-terrigenic; Middle Pliocene, oil-gas-bituminous-terrigenic; diatom-oil bearing-sand-clay; Miocene, oil-bituminous-sand-aleurite; Upper Oligocene-Miocene, oil bearing-terrigenic-carbonate; Eocene, oil bearing-clay-sand-marly; Upper Cretaceous, oil bearing-carbonate; Lower Cretaceous, oil bearing-terrigenic-carbonate; Upper Jurassic, oil bearing-sand-aleurite.


2021 ◽  
Vol 9 ◽  
Author(s):  
Xinxing Cao ◽  
Zhiguang Song ◽  
Sibo Wang ◽  
Puliang Lyu

Maoming oil shales are typical low-altitude lacustrine sediments that were deposited during the late Paleogene. The hydrocarbon composition and compound-specific stable carbon isotopic composition (δ13C) of organic matter in the profile samples of the oil shales have been analyzed. The results show that algae and aquatic plants are major parent sources of the organic matter in the oil shales associated with a small portion of terrestrial higher plant input. The δ13C composition of the bulk organic matter and the n-alkanes varies greatly on the profile from −26.9 to −15.8‰ and −31.7 to −16.2‰, respectively. While a good positive correlation among the δ13C composition of individual n-alkanes implies that these n-alkanes were originated from the similar source input. The δ13C composition of n-alkanes on the profile displays a positive excursion trend from the bottom to the top, and this excursion was likely related to the general decreasing trend of the partial pressure of atmospheric CO2 (pCO2) during the late Paleogene. The δ13C composition of the C30-4-methyl steranes ranges from −11.9 to −6.3‰, which is suggestive of Dinoflagellates-related source input. Coincidently, the high abundance C33-botryococcanes were detected in the samples on the top section of the profile and display an extremely positive carbon isotopic composition of −4.5 to −8.4‰, suggesting that the lower partial pressure of atmospheric CO2 had triggered a bicarbonate consumption mechanism for Botryococcus braunii B. Therefore, the δ13C composition of n-alkanes and C33-botryococcanes and their profile variation suggest that a general declining process associated with fluctuation in the partial pressure of atmospheric CO2 is likely the major reason for the rapid climatic changes toward the end of the late Paleogene.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Youhong Sun ◽  
Demchig Tsolmon ◽  
Xuanlong Shan ◽  
Wentong He ◽  
Wei Guo

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.


Sign in / Sign up

Export Citation Format

Share Document