Petrophysics and Geochemistry of Unconventional Reservoirs

A special issue of Geosciences (ISSN 2076-3263). This special issue belongs to the section "Geochemistry".

Deadline for manuscript submissions: closed (1 May 2021) | Viewed by 40355

Special Issue Editor


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Guest Editor
Skolkovo Institute of Science and Technology, Nobel Street 3, Moscow 121205, Russia
Interests: unconventional reservoirs; hard-to-recover reserves; petrophysics; lithology; geochemistry; isotope geochemistry; enhanced hydrocarbon recovery; reactive transport modeling
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Special Issue Information

Dear Colleagues,

Together with the Editorial Board, we are pleased to announce a Special Issue of Geosciences dedicated to unconventional reservoirs and their characterization.

Unconventional reservoirs are discovered in all hydrocarbon basins around the world. Their exploration and production is an increasingly important challenge for the oil and gas industry due to maturity and depletion of conventional plays. The complexity of unconventional formations associated with high production costs leads to significant uncertainties and risks when it comes to the development of such reserves. Unconventional kerogen rich reservoirs exhibit high heterogeneity in a wide range of scales while their many physical properties are typically highly anisotropic.  Comprehensive petrophysical and geochemical studies are of particular importance in the analysis of petroleum generation and maturation processes in unconventional plays. Multivariate study of kerogen rich rocks is essential for development and optimization of production technologies, including hydraulic fracturing and various methods of enhanced hydrocarbon recovery. Consequently, multidisciplinary approaches in evaluation of unconventional formations are an essential part of successful exploration and development projects.

The Special Issue aims to reflect new ideas, concepts, and methods in research related to petrophysics, lithology, and geochemistry of unconventional formations, including but not limited to collector properties, mechanical and thermal properties, molecular and isotope composition of organic matter, as well as mechanisms of rock and organic matter transformations under the effect of temperature and pressure.

Prof. Mikhail Spasennykh
Guest Editor

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Keywords

  • Unconventional reservoirs 
  • Reservoir characterization 
  • Petrophysics 
  • Lithostratigraphy 
  • Logging and log interpretation 
  • Core and fluid analysis 
  • Pore space structure 
  • Geomechanics 
  • Geochemistry 
  • Biomarkers 
  • Isotope geochemistry

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Published Papers (14 papers)

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Editorial

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6 pages, 178 KiB  
Editorial
A Summary of “Petrophysics and Geochemistry of Unconventional Reservoirs”
by Mikhail Spasennykh, Evgeny Chekhonin and Evgenia Leushina
Geosciences 2021, 11(11), 453; https://doi.org/10.3390/geosciences11110453 - 2 Nov 2021
Cited by 1 | Viewed by 1760
Abstract
Unconventional reservoirs are discovered in all petroleum basins around the world [...] Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)

Research

Jump to: Editorial

7 pages, 12355 KiB  
Article
δ13C and δD Values of n-Alkanes from In-Reservoir Biodegraded Oils: Implications for Understanding the Mechanisms of Biodegradation and for Petroleum Exploration
by Nikolai Pedentchouk, Barry Bennett and Steve Larter
Geosciences 2021, 11(9), 365; https://doi.org/10.3390/geosciences11090365 - 30 Aug 2021
Cited by 2 | Viewed by 2286
Abstract
This study investigates the magnitude and direction of stable C and H isotope shifts of n-C15–30 alkanes from biodegraded oils sourced from Type II (Oil suite S) and Type II/III (Oil suite H) kerogens. Compound-specific isotope data show a 2.0‰ 13 [...] Read more.
This study investigates the magnitude and direction of stable C and H isotope shifts of n-C15–30 alkanes from biodegraded oils sourced from Type II (Oil suite S) and Type II/III (Oil suite H) kerogens. Compound-specific isotope data show a 2.0‰ 13C-enrichment and no D-enrichment of n-alkanes in the most biodegraded oil from sample suite S. Similarly, there is a 1.5–2.5‰ 13C-enrichment and no D-enrichment in Oil suite H. Overall, there is a <2.5‰ δ13C and <20‰ δD variability among individual n-alkanes in the whole sequence of biodegradation. N-alkanes from the least biodegraded Oil H samples are 2–4‰ 13C-enriched in comparison with the least biodegraded Oil S. However, there are no differences in the δD values of n-alkanes in these samples. Our indirect isotopic evidence suggests (1) a site-specific biodegradation process, most likely at position C-2 and/or C-3 or another site-specific process, and (2) a significant D/H exchange between organic compounds in the source rock and isotopically similar marine formation waters. We conclude that, unlike δD methodology, investigation of δ13C composition of n-alkanes has strong potential as a supplementary tool for oil–oil and oil–source-rock correlation even in biodegraded oils when n-alkanes are present. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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15 pages, 5492 KiB  
Article
Pyrite Morphology and δ34S as Indicators of Deposition Environment in Organic-Rich Shales
by Elizaveta Idrisova, Rinat Gabitov, Tagir Karamov, Andrey Voropaev, Ming-Chang Liu, Natalia Bogdanovich and Mikhail Spasennykh
Geosciences 2021, 11(9), 355; https://doi.org/10.3390/geosciences11090355 - 24 Aug 2021
Cited by 5 | Viewed by 2859
Abstract
This study is focused on the mineralogical, chemical, and isotopic characterization of pyrites from the rocks of the Bazhenov Formation (Upper Jurassic–Lower Cretaceous organic-rich shales, Western Siberia, Russia). Scanning electron microscopy (SEM) revealed pyrites of different morphologies: small and large framboids, small crystals, [...] Read more.
This study is focused on the mineralogical, chemical, and isotopic characterization of pyrites from the rocks of the Bazhenov Formation (Upper Jurassic–Lower Cretaceous organic-rich shales, Western Siberia, Russia). Scanning electron microscopy (SEM) revealed pyrites of different morphologies: small and large framboids, small crystals, and large euhedral crystals; all morphotypes were usually combined into aggregates. Isotope ratio mass spectrometry (IRMS) and secondary ion mass spectrometry (SIMS) showed that small framboids and microcrystalline pyrite are isotopically light, with δ34SCDT varying from −55 to −20‰. Large framboids and euhedral crystals of pyrite are isotopically heavy with δ34SCDT up to +26‰. Both morphology and δ34S were suggested to be controlled by the redox conditions and sedimentation regime. The abundance of small framboids suggests that pyrite sedimentation occurred under anoxic conditions; the presence of the large framboids and euhedral crystals of pyrite suggest the accumulation of sediments occurred at suboxic conditions, possibly in the presence of oxygen. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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33 pages, 5311 KiB  
Article
Advanced Determination of Heat Flow Density on an Example of a West Russian Oil Field
by Yury Popov, Mikhail Spasennykh, Anuar Shakirov, Evgeny Chekhonin, Raisa Romushkevich, Egor Savelev, Anastasia Gabova, Dzhulia Zagranovskaya, Rim Valiullin, Rashid Yuarullin, Inessa Golovanova and Raushaniya Sal’manova
Geosciences 2021, 11(8), 346; https://doi.org/10.3390/geosciences11080346 - 18 Aug 2021
Cited by 4 | Viewed by 2855
Abstract
Reliable geothermal data are required for basin and petroleum system modeling. The essential shortcomings of the methods and results of previous geothermal investigations lead to a necessity to reappraise the data on the thermal properties and heat flow. A new, advanced experimental basis [...] Read more.
Reliable geothermal data are required for basin and petroleum system modeling. The essential shortcomings of the methods and results of previous geothermal investigations lead to a necessity to reappraise the data on the thermal properties and heat flow. A new, advanced experimental basis was used to provide reliable data on vertical variations in the thermal properties of formation and heat flow for the area surrounding a prospecting borehole drilled through an unconventional hydrocarbon reservoir of the Domanik Formation in the Orenburg region (Russia). Temperature logging was conducted 12.5 months after well drilling. The thermal properties of the rocks were measured with continuous thermal core profiling on all 1699 recovered core samples. Within non-cored intervals, the thermal conductivity of the rocks was determined from well-logging data. The influence of core aging, multiscale heterogeneity and anisotropy, in situ pressure and temperature on the thermal properties of rock was accounted for. The terrestrial heat flow was determined to be 72.6 ± 2.2 mW·m−2—~114% larger than the published average data for the studied area. The experiment presents the first experience of supporting basin modeling in unconventional plays with advanced experimental geothermal investigations. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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28 pages, 7552 KiB  
Article
Upper Jurassic–Lower Cretaceous Source Rocks in the North of Western Siberia: Comprehensive Geochemical Characterization and Reconstruction of Paleo-Sedimentation Conditions
by Evgeniya Leushina, Timur Bulatov, Elena Kozlova, Ivan Panchenko, Andrey Voropaev, Tagir Karamov, Yakov Yermakov, Natalia Bogdanovich and Mikhail Spasennykh
Geosciences 2021, 11(8), 320; https://doi.org/10.3390/geosciences11080320 - 30 Jul 2021
Cited by 5 | Viewed by 2398
Abstract
The present work is devoted to geochemical studies of the Bazhenov Formation in the north of the West Siberian Petroleum Basin. The object is the Upper Jurassic–Lower Cretaceous section, characterized by significant variations in total organic carbon content and petroleum generation potential of [...] Read more.
The present work is devoted to geochemical studies of the Bazhenov Formation in the north of the West Siberian Petroleum Basin. The object is the Upper Jurassic–Lower Cretaceous section, characterized by significant variations in total organic carbon content and petroleum generation potential of organic matter at the beginning of the oil window. The manuscript presents the integration of isotopic and geochemical analyses aimed at the evaluation of the genesis of the rocks in the peripheral part of the Bazhenov Sea and reconstruction of paleoenvironments that controlled the accumulation of organic matter in sediments, its composition and diagenetic alterations. According to the obtained data, the sediments were accumulated under marine conditions with a generally moderate and periodically increasing terrigenous influx. The variations in organic matter composition are determined by redox conditions and terrigenous input which correlate with the eustatic sea level changes during transgressive/regressive cycles and activation of currents. Transgression is associated with an intensive accumulation of organic matter under anoxic to euxinic conditions and insignificant influence of terrigenous sources, resulting in the formation of rocks with oil-generating properties. During the regression periods, the terrigenous sedimentation increased along with the dissolved oxygen concentration, and deposits with low organic matter content and gas-generating properties were formed. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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17 pages, 3609 KiB  
Article
Geochemical Trends Reflecting Hydrocarbon Generation, Migration and Accumulation in Unconventional Reservoirs Based on Pyrolysis Data (on the Example of the Bazhenov Formation)
by Mikhail Spasennykh, Polina Maglevannaia, Elena Kozlova, Timur Bulatov, Evgeniya Leushina and Nikita Morozov
Geosciences 2021, 11(8), 307; https://doi.org/10.3390/geosciences11080307 - 24 Jul 2021
Cited by 15 | Viewed by 3431
Abstract
The current study is devoted to the determination and interpretation of geochemical trends reflecting hydrocarbon generation, migration and accumulation in unconventional reservoirs; the study is performed on the Bazhenov shale rock formation (Western Siberia, Russia). Results are based on more than 3000 Rock-Eval [...] Read more.
The current study is devoted to the determination and interpretation of geochemical trends reflecting hydrocarbon generation, migration and accumulation in unconventional reservoirs; the study is performed on the Bazhenov shale rock formation (Western Siberia, Russia). Results are based on more than 3000 Rock-Eval analyses of the samples from 34 wells drilled in the central part of the West Siberian petroleum basin, which is characterized by common marine sedimentation environments. Pyrolysis studies were carried out before and after the extraction of rocks by organic solvent. As a result, we have improved the accuracy of kerogen content and maturity determination and complemented the standard set of pyrolysis parameters with the content of heavy fraction of hydrocarbons. The data obtained for the wells from areas of different organic matter maturity was summarized in the form of cross-plots and diagrams reflecting geochemical evolution of the source rocks from the beginning to the end of the oil window. Interpretation of the obtained results revealed quantitative trends in the changes of generation potential, amount, and composition of generated hydrocarbons in rocks at different stages of oil generation process. The analysis of geochemical trends allowed us to improve approaches for the productivity evaluation of the formation and study the effect of organic matter maturity on distribution of productive intervals of different types. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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17 pages, 7628 KiB  
Article
Lithological and Geochemical Heterogeneity of the Organo-Mineral Matrix in Carbonate-Rich Shales
by Natalia Bogdanovich, Elena Kozlova and Tagir Karamov
Geosciences 2021, 11(7), 295; https://doi.org/10.3390/geosciences11070295 - 16 Jul 2021
Cited by 5 | Viewed by 2449
Abstract
The paper discusses the issues of interaction of the organic matter and the siliceous-carbonate mineral matrix in unconventional reservoirs of the Upper Devonian Domanik Formation of the Upper Kama Depression of the Volga-Ural Basin. The Domanik Formation is composed of organic-rich low-permeability rocks. [...] Read more.
The paper discusses the issues of interaction of the organic matter and the siliceous-carbonate mineral matrix in unconventional reservoirs of the Upper Devonian Domanik Formation of the Upper Kama Depression of the Volga-Ural Basin. The Domanik Formation is composed of organic-rich low-permeability rocks. Lithological and geochemical peculiarities of rocks were studied using light microscopy, X-ray diffraction analysis (XRD), scanning electronic microscopy (SEM), and evaporation method. Organic matter was examined by the Rock-Eval pyrolysis with quantitative and qualitative evaluation of generation potential and maturity degree. Integrated analysis of results of lithological and geochemical studies allowed identifying intervals in the studied section where organic matter can form a complex association with the siliceous-carbonate matrix. It was fixed experimentally that in some cases the mineral carbonate matrix and the organic matter form a one-whole high-molecular compound. The authors supposed that in the course of sedimentation, organic matter is immobilized into the structure of the mineral carbonate matrix. At the deposition and diagenesis stage, the carbonate matter interacts with acids of the organic matter and forms natural organo-mineral polymers. Special physicochemical properties of such organo-mineral associations shed new light onto the problems of producing from hard-to-develop nonconventional carbonate reservoirs and evaluating the associated risks. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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31 pages, 12969 KiB  
Article
Laboratory Investigation of Hydraulic Fracture Behavior of Unconventional Reservoir Rocks
by Maria Bobrova, Sergey Stanchits, Anna Shevtsova, Egor Filev, Vladimir Stukachev and Tagir Shayahmetov
Geosciences 2021, 11(7), 292; https://doi.org/10.3390/geosciences11070292 - 15 Jul 2021
Cited by 10 | Viewed by 3131
Abstract
The heterogeneity of the rock fabric is a significant factor influencing the initiation and propagation of a hydraulic fracture (HF). This paper presents a laboratory study of HF created in six shale-like core samples provided by RITEK LLC collected from the same well, [...] Read more.
The heterogeneity of the rock fabric is a significant factor influencing the initiation and propagation of a hydraulic fracture (HF). This paper presents a laboratory study of HF created in six shale-like core samples provided by RITEK LLC collected from the same well, but at different depths. For each tested sample, we determined the breakdown pressure, the HF growth rate, and the expansion of the sample at the moment when the HF reaches the sample surface. Correlations were established between the HF parameters and the geomechanical characteristics of the studied samples, and deviations from the general relationships were explained by the influence of the rock matrix. The analysis of the moment tensor inversion of radiated acoustic emission (AE) signals allows us to separate AE signals with a dominant shear component from the signals with a significant tensile component. The direction of microcrack opening was determined, which is in good agreement with the results of the post-test X-ray CT analysis of the created HF. Thus, it has been shown that a combination of several independent laboratory techniques allows one to reliably determine the parameters that can be used for verification of hydraulic fracturing models. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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21 pages, 4047 KiB  
Article
Study of Organic Matter of Unconventional Reservoirs by IR Spectroscopy and IR Microscopy
by Natalya Tanykova, Yuliya Petrova, Julia Kostina, Elena Kozlova, Evgenia Leushina and Mikhail Spasennykh
Geosciences 2021, 11(7), 277; https://doi.org/10.3390/geosciences11070277 - 30 Jun 2021
Cited by 23 | Viewed by 3874
Abstract
The study of organic matter content and composition in source rocks using the methods of organic geochemistry is an important part of unconventional reservoir characterization. The aim of this work was the structural group analysis of organic matter directly in the source rock [...] Read more.
The study of organic matter content and composition in source rocks using the methods of organic geochemistry is an important part of unconventional reservoir characterization. The aim of this work was the structural group analysis of organic matter directly in the source rock in combination with a quantitative assessment and surface distribution analysis of the rock sample by FTIR spectroscopy and FTIR microscopy. We have developed new experimental procedures for semi-quantitative assessment of the organic matter content, composition and distribution in the source rocks and applied these procedures for the study of the samples from the Bazhenov shale formation (West Siberia, Russia). The results have been verified using the data from the study of organic matter obtained by Rock-Eval pyrolysis and differential thermal analysis. The obtained results demonstrate the prospects of FTIR spectroscopy and FTIR microscopy application for non-destructive and express analysis of the chemical structure and distribution of organic matter in rocks. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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12 pages, 4389 KiB  
Article
Types of Void Space in the Bazhenov Reservoir Rocks
by Olga V. Postnikova, Alexander V. Postnikov, Olga A. Zueva, Artem E. Kozionov, Ekaterina V. Milovanova and Lyubov A. Savinova
Geosciences 2021, 11(7), 269; https://doi.org/10.3390/geosciences11070269 - 25 Jun 2021
Cited by 5 | Viewed by 2218
Abstract
The deposits of the Bazhenov formation are a unique reservoir of unconventional oil reserves in Western Siberia. They contain both solid organic matter (kerogen) and liquid light oil. The successful development of these hydrocarbons is largely determined by the adequacy of the void [...] Read more.
The deposits of the Bazhenov formation are a unique reservoir of unconventional oil reserves in Western Siberia. They contain both solid organic matter (kerogen) and liquid light oil. The successful development of these hydrocarbons is largely determined by the adequacy of the void space models. The aim of the study is to identify the types of void space in the sediments of the Bazhenov formation and to identify the distribution patterns across the section of the researched wells. The void space was studied by electron and optical microscopy, and the mineral composition of the rocks was determined by X-ray diffraction analysis. The deposits of the Bazhenov productive formation in the territory of Western Siberia are represented by a wide complex of lithotypes, including various kinds of silicites, carbonate, clay rocks, and mixtites. The reservoir space in the reservoir rocks of the Bazhenov formation is a complex and hierarchically subordinated system, which includes voids and fractures of various sizes, configurations, and genesis. The void space of the Bazhenov formation is characterized by a fairly high degree of spatial heterogeneity, which is controlled by lithological, facies, and tectonic factors, as well as the direction of catagenetic processes. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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16 pages, 2590 KiB  
Article
Application of the Data on δ13C and δ18O of Carbonates for the Study of Unconventional Reservoirs on the Example of the Bazhenov Source Rocks, Western Siberia, Russia
by Anna Yurchenko, Andrey Voropaev, Elena Kozlova, Nikita Morozov and Mikhail Spasennykh
Geosciences 2021, 11(7), 264; https://doi.org/10.3390/geosciences11070264 - 22 Jun 2021
Cited by 5 | Viewed by 2552
Abstract
This paper addresses potential application of data on stable carbon and oxygen isotope composition of carbonates for study of organic rich source rocks on the example of the Late Jurassic–Early Cretaceous Bazhenov Formation (West Siberian petroleum basin, Russia). Geochemical studies were conducted for [...] Read more.
This paper addresses potential application of data on stable carbon and oxygen isotope composition of carbonates for study of organic rich source rocks on the example of the Late Jurassic–Early Cretaceous Bazhenov Formation (West Siberian petroleum basin, Russia). Geochemical studies were conducted for sections located in central (most productive) and peripheral (northern and southern) regions of the Bazhenov Formation distribution area, containing deposits formed under different conditions. We identified key factors impacting stable isotope composition of carbonate minerals and established relation of their isotope composition to the formation conditions. Using a thermodynamic model of carbon and oxygen isotope exchange in the carbonate–water–carbon dioxide system, it is shown that variations in the isotope composition of secondary carbonates are affected by isotopic composition of primary carbonates in sediments and by the isotope exchange reactions with water and carbon dioxide, generated during the source rocks transformation. Our results demonstrate that stable isotope data for carbonates in the Bazhenov Formation together with standard geochemical methods can be efficiently applied to determine sedimentation conditions and secondary alteration processes of oil source rocks. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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22 pages, 10996 KiB  
Article
Integration of Thermal Core Profiling and Scratch Testing for the Study of Unconventional Reservoirs
by Evgeny Chekhonin, Yuri Popov, Raisa Romushkevich, Evgeny Popov, Dzhuliia Zagranovskaya and Vladislav Zhukov
Geosciences 2021, 11(6), 260; https://doi.org/10.3390/geosciences11060260 - 17 Jun 2021
Cited by 3 | Viewed by 1949
Abstract
Core analysis provides the essential information necessary for the characterization and development of hydrocarbon reservoirs. High core-scale heterogeneity and anisotropy, natural in unconventional reservoirs, complicate reservoir characterization and dictate the sampling methodology used. Continuous high-resolution thermal measurements with an optical scanner and scratcher [...] Read more.
Core analysis provides the essential information necessary for the characterization and development of hydrocarbon reservoirs. High core-scale heterogeneity and anisotropy, natural in unconventional reservoirs, complicate reservoir characterization and dictate the sampling methodology used. Continuous high-resolution thermal measurements with an optical scanner and scratcher along the core column can yield benefits in a sampling strategy. This article describes some features of the suggested integration of non-destructive thermal profiling with partially destructive scratch testing applied for the study of rocks from the Bazhenov Formation (West Siberia, Russia). The spatial variation in the unconfined compressive strength and thermal conductivity components parallel and perpendicular to bedding for more than 1000 samples are demonstrated and discussed on core and log scales. The relationships between these properties are established for different rock types composing the formation. The joint analysis allows specialists to correctly define multiscale heterogeneities and facies that would be difficult or impossible to observe with logging data analysis or geological description alone. The established relationships make it possible to partially replace the semi-destructive scratch test with non-destructive optical scanning, providing UCS estimation. One more important outcome of the present work is the lessons learned regarding how to organize future works. The integration of thermal core profiling and scratch testing data looks promising for unconventional reservoir characterization. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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21 pages, 5337 KiB  
Article
Alginite-Rich Layers in the Bazhenov Deposits of Western Siberia
by Timur Bulatov, Elena Kozlova, Evgeniya Leushina, Ivan Panchenko, Natalia Pronina, Andrey Voropaev, Nikita Morozov and Mikhail Spasennykh
Geosciences 2021, 11(6), 252; https://doi.org/10.3390/geosciences11060252 - 11 Jun 2021
Cited by 8 | Viewed by 3085
Abstract
In this study, we identified the luminescent layers containing a significant amount of alginite in the Upper Jurassic–Lower Cretaceous Bazhenov Formation named “the alginite-rich layers”. Lithological and geochemical methods were used to determine distinctive features of these layers and to evaluate their impact [...] Read more.
In this study, we identified the luminescent layers containing a significant amount of alginite in the Upper Jurassic–Lower Cretaceous Bazhenov Formation named “the alginite-rich layers”. Lithological and geochemical methods were used to determine distinctive features of these layers and to evaluate their impact on the total petroleum generation potential of the Bazhenov Formation. We have shown that the composition of the alginite-rich layers differs significantly from the organic-rich siliceous Bazhenov rocks. Rock-Eval pyrolysis, bulk kinetics of thermal decomposition, elemental analysis, and the composition of pyrolysis products indicate type I kerogen to be the predominant component of the organic matter (OM). Isotope composition of carbon, nitrogen, and sulfur was used to provide insights into their origin and formation pathways. The luminescent alginite-rich layers proved to be good regional stratigraphic markers of the Bazhenov Formation due to widespread distribution over the central part of Western Siberia. They can also be applied for maturity evaluation of the deposits from immature to middle of the oil window, since the luminescence of the layers changes the color and intensity during maturation. Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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28 pages, 12864 KiB  
Article
Advanced Methods of Thermal Petrophysics as a Means to Reduce Uncertainties during Thermal EOR Modeling of Unconventional Reservoirs
by Evgeny Chekhonin, Raisa Romushkevich, Evgeny Popov, Yury Popov, Alexander Goncharov, Konstantin Pchela, Maxim Bagryantsev, Alexey Terentiev, Ivan Kireev and Sergey Demin
Geosciences 2021, 11(5), 203; https://doi.org/10.3390/geosciences11050203 - 7 May 2021
Cited by 5 | Viewed by 2627
Abstract
Within the vast category of unconventional resources, heavy oils play an essential role as related resources are abundant throughout the world and the amount of oil produced using thermal methods is significant. Simulators for thermo–hydro–dynamic modeling, as a mandatory tool in oilfield development, [...] Read more.
Within the vast category of unconventional resources, heavy oils play an essential role as related resources are abundant throughout the world and the amount of oil produced using thermal methods is significant. Simulators for thermo–hydro–dynamic modeling, as a mandatory tool in oilfield development, are continuously improving. However, the present paper shows that software capabilities for the integration of data on the rock thermal properties necessary for modeling are limited, outdated in some aspects, and require revision. In this paper, it is demonstrated that a characteristic lack of reliable data on rock thermal properties also leads to significant errors in the parameters characterizing oil recovery efficiency. A set of advanced methods and equipment for obtaining reliable data on thermal properties is presented, and a new, vast set of experimental data on formation thermal properties obtained from the Karabikulovskoye heavy oil field (Russia) is described. The time-dependent results of modeling oil recovery at the field segment using the steam-assisted gravity drainage method with both published and new data are discussed. It is shown that the lack of experimental data leads to significant errors in the evaluation of the cumulative oil production (up to 20%) and the cumulative steam/oil ratio (up to 52%). Full article
(This article belongs to the Special Issue Petrophysics and Geochemistry of Unconventional Reservoirs)
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