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EAGE/SPE Workshop on Shale Science 2021
- Conference date: April 5-6, 2021
- Location: Moscow, Russia
- Published: 05 April 2021
28 results
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Numerical Study of Deformation Processes During Core Recovery on The Example of a Layered Medium an Unconventional Reservoir
Authors E. Grishko, Y. Stefanov, R. Bakeev and A. MyasnikovSummaryRecently in geomechanics, much attention has been paid not only to the quality of geomechanical laboratory tests but also to maintaining the quality of the core from which the samples are drilled. During core drilling, two types of impact on the core can be defined: mechanical impact of the drill head to break the rock and form the core; change in the load at the boundaries of the core and wellbore, which is determined by the pressure of the drilling fluid. In this work, a numerical algorithm has been developed and implemented in 3D code, which simulates the creation of new surfaces in the process of core recovery and setting on them boundary conditions corresponding to the pressure of the drilling fluid, as well as the effect of the drilling tool. On its basis, a numerical study of deformation and fracture processes during core recovery for a real layered medium of an unconventional reservoir was performed.
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Probabilistic Assessment of Oil Reserves of Unconventional Reservoirs in Domanik Deposits
Authors V.I. Poroskun, E.N. Soboleva and A.V. ShalomeenkoSummaryTaking into account the uncertainty of the parameters adopted in the deterministic assessment of reserves, a probabilistic assessment of oil reserves of unconventional deposits in the Domanik deposits of the Troitskoe and Krasnogorskoe fields was carried out to assess the veracity.
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Determination of Recoverable Oil Reserves in Sediments of The Bazhenov Formation
More LessSummaryDetermination of recoverable oil reserves in sediments of the Bazhenov formation
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Exploration of Bazhen-Abalak Complex at Krasnoleninsky Arch by Seismic Methods
Authors I. Musatov, A. Novokreschin, E. Gaifulina and M. GrischenkoSummaryThe paper presents the results of prediction of geological parameters for Bazhen-Abalak complex by the product of elastic moduli restored by simultaneous and stochastic inversion combined with structural attributes. In the process of geological properties prediction, this combination enables to account for both inherent characteristics of the media associated with mineral organization and external ones that result from tectonic deformation.
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Peculiarities of The Structure of Productive Layers and Perspective Zone Localization of Unconventional Reservoir on The Example of a West Siberian Oilfield
Authors M. Grischenko, M. Smishlayeva, E. Avramenko, I. Musatov, I. Oshnyakov and L. MelnikovSummaryThe area of research was delineated at the 400-km2 Em-Egovsky license block. Research work was attempted at this block for the purpose of developing the hydrocarbon reserves localization technology in Bazhen-Abalak complex (BAC). As a result, 14 petrotypes (reservoir and non-reservoir) were identified, 5 fracture zones were singled out and algorithms of volumetric parameters and brittleness for BAC were obtained. On the basis of detailed 3D geological model of double porosity methodological algorithms for productive zones localization were proposed using key parameters. Regions of experimental-industrial drilling with first ordered wells were proposed for confirmation and exploration of high-potential zones.
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Shale Strata of The Azov-Kuban Oligocene-Miocene Generation-Accumulation Hydrocarbon System
Authors A. Kudryashov, V. Kerimov and N. YandarbievSummaryThe paper considers the Shale strata of the Azov-Kuban Oligocene-Miocene generation-accumulation hydrocarbon system. The Maikop series in the study area is a hybrid phenomenon, including both oil and gas source properties and hydrocarbon accumulating complexes-natural reservoirs. The study of these objects allows us to conclude that organic porosity plays an important role in determining the total volume of the accumulated part of hydrocarbons in the oil and gas source strata. In dense immature kerogen, during oil formation, organic pores ("kerogen porosity") begin to form, which towards the end of the main oil formation zone form a coherent system that provides space for newly formed oil hydrocarbons.
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Geochemical Characteristics of Organic Matter and Oils of The Bazhenov and Domanik Shale Formations in Connection with The Prediction of Their Oil-Bearing Prospects
Authors M. Dakhnova, Y. Kiseleva and S. MozhegovaSummaryThe Bazhenov and Domanik formations are organic carbon-rich shale-like sediments. The specific feature of their structure is the alternation of highly and less enriched with organic matter interlayers. Such structure of the formation makes it difficult for the HC to escape from the strata. The distribution of oil in high-carbon shale-like strata depends mainly on the original content of total organic carbon (TOC before active oil and gas generation), as well as on OM thermal maturity. The paper observes geochemical approaches to prediction and estimation of hydrocarbon resources of shale-like strata on the example of the Bazhenov and Domanik formations.
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Approaches to Studying of Associated Gas Diffusion in Oil Saturated Shale Core Samples
Authors P. Khmelenko, E. Mukhina, A. Mukhametdinova, V. Lompik, A. Ushakova, M. Zvada and A. CheremisinSummaryDiffusion is a key mechanism controlling the transport of hydrocarbons between fractures and matrix in low permeable shales in associated gas EOR. Diffusion in shales plays more important role than in conventional reservoirs, however low reservoir properties are the reasons for emerging issues in understanding and modelling of multiphase flows. Furthermore, literature does not provide reliable data on gas diffusion inside oil saturated shale core samples under reservoir conditions. Following this, laboratory modelling of associated gas diffusion and calculation of diffusion coefficient inside shale core samples will decrease the uncertainty in production modelling. Traditional ways of diffusion measurements are not applicable in shales because of low permeability values. NMR and CT scanning are promising technologies for such type of shale core analysis. The NMR measurements are based on recalculation of NMR relaxation signals to saturations, and as a result, to concentrations, which allows to determine diffusion coefficients based on Fick`s law. The principle of measurements in CT is based on tracking the difference in CT numbers dependent on oil and gas densities inside the core within the gas diffusion process. The received CT data can be recalculated to saturations and used in numerical model for gas diffusion coefficient estimation.
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Study of the Bazhenov Formation Kerogen by Fourier Transform Infrared Spectroscopy
Authors N. Tanykova, Yu. Petrova, M. Spasennykh and E. KozlovaSummaryInformation on the structural-group composition of organic matter is important for the evaluation of kerogen maturity and oil generation potential of unconventional reservoir rocks. In the work kerogen samples (type II) of the Bazhenov formation of the West Siberian oil and gas basin have been studied. On the example of unconverted kerogen and the middle of oil window kerogen samples, the possibilities of structural-group analysis of the high-carbon organic matter of the Bazhenov formation by FTIR spectroscopy by recording transmission and attenuated total reflectance spectra have been shown. It has also been shown, that the IR-coefficients characterizing aromaticity, branching and aliphaticity of organic matter allow to evaluate the maturity degree using on the example of type II kerogen, and the obtained data are in good agreement with the results of Rock-Eval pyrolysis and elemental analysis.
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The Structural Features Unconventional Reservoirs Domanik Type of rocks
Authors D. Zagranovskaya, S. Isaeva, А.P. Vilesov and O. ZakharovaSummaryProperties of unconventional prospective deposits are interconnected by the processes of reservoir formation and oil and gas formation. Dispersed dolomite in situ formed during the maturation of TOC from syngenetic magnesium in the rock matrix increases the void space of the rock, thereby forming an unconventional reservoir filled with autochthonous hydrocarbons and oil components. In the process of TOC maturation and hydrocarbon migration, the TOC components are redistributed in the void space, thereby, the released volume of rocks is filled with stationary resinous asphaltene substances, which sharply reduces the reservoir properties of unconventional reservoirs. As a result, the definition of "organic" porosity includes a broader concept than just the porosity of kerogen. This is a more complex physicochemical process of transformation of the organic matter itself and the redistribution of elements within the formation as a result of the maturation of TOC components and hydrocarbon migration. When assessing the oil and gas potential in the section, we distinguish three groups of rocks: unconventional reservoirs with an increased TOC content and the presence of mobile hydrocarbons; bituminous rocks, in which part of the pore volume is filled with resinous-asphaltene substances and host dense carbonate rocks without organic matter. Also, sporadically developed traditional reservoirs are distinguished throughout the section of the Domanik type of rocks.
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Scientific Basis of Hydrocarbons Generation and Accumulation in Bazhenov Formation Rocks: Comparison of Rock Samples Investigation and Laboratory Modeling Results
Authors A. Kalmykov, G. Savostin, M. Tikhonova, V. Levkina, D. Ivanova, O. Vidischeva, G. Kalmykov and A. BychkovSummaryComplex investigation of Bazhenov source rocks was made to study patterns of hydrocarbons generation and accumulation. Sequent soxhlet extraction and heating in autoclaves with water were used to determine amount of existing and generated hydrocarbons in the rocks. Composition of hydrocarbons was investigated using GC-MS. It was shown that kerogen maturity plays role in the accumulation of generated compounds, and asphaltenes might block part of pore space. Rock composition affects process of hydrocarbons generation. Espetially amount of silica and carbonates. In the middle-end of oil window some oil migrates higher through the section, some is captured with asphaltenes, and hydrocarbons from lower formations can move inside Bazhenov formation. Experiments that model hydrocarbons generation show good agreement with natural processes. It was found that the highest amount of newly formed compounds accumulate in the rocks, and at least half of hydrocarbons is blocked with asphaltenes. Kerogen nature highly affect the process of n-alkanes, polyaromatic compounds and other hydrocarbons generatinon. The method designed in this work allows investigating the nature of kerogen, model processes of hydrocarbons generation and accumulation, and increase accuracy of basin modeling and oil fields search.
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Improving The Reliability of Basin Modeling Results by Enhancement of Determination of Geothermal Characteristics and Their Integration into Basin Model
Authors E. Chekhonin, Y. Popov, A. Vladimirov, M. Spasennykh, D. Zagranovskaya and O. ZakharovaSummaryRecently developed techniques for obtaining a geothermal dataset (rock thermal conductivity, volumetric heat capacity, thermal anisotropy, and heat flow) were applied for a well drilled in the Baleykinskoe oilfield (Orenburg region) that significantly improved the reliability of the geothermal data required for basin modeling. However, there are pitfalls in setting the reliable thermal conductivity and heat flow in a numerical basin representation that can reduce the quality of the final basin model. We proposed an advanced workflow for setting these characteristics into basin models and demonstrated its effectiveness on the example of a one-dimensional model specially built using the data determined for the well. It was established that using the traditional method of obtaining and setting geothermal characteristics in the model overestimates the transformation ratio of organic matter and therefore the mass of the generated hydrocarbon volume (by 30%). The application of the developed methodology of determination geothermal characteristics and its integration into a model is necessary in work involving basin and petroleum system modeling to avoid serious errors, which are practically inevitable in the opposite cases.
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Important Evaluation Parameters for Unconventional Reservoirs of Paleogenic Sediments of Central and Eastern Caucasia
By Y. VarovSummaryAn important aspect for exploration work is the presence of critical parameters of the productive deposits. To solve this problem, a table was compiled with this information for unconventional reservoirs of North America. When analyzing the logging data, it was shown that as the clay content decreases (less than 75%) and the porosity increases (more than 9%), the probability of the appearance of productive intervals in the Paleogene sediments of the Central and Eastern Ciscaucasia increases. Geomechanical properties make it possible to differentiate between brittle and ductile deposits. The intervals with maximum fractures and permeability are characterized by Young’s modulus of more than 20 GPa and Poisson’s ratio of less than 0.3. The importance of considering flexural faults in the interpretation of seismic data is shown. The integration of various geometric attributes and seismic inversion makes it possible to identify sweet spots for place a horizontal wells and performing hydraulic fracturing.
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Prediction of Geomechanical Parameters Based on Anisotropic Rock Physics Model of Khadumites of the Eastern and Central Ciscaucasia
Authors I. Bayuk, D. Danko, V. Ryzhkov and M. KulapovaSummaryThe khadumites of the Eastern and Central Ciscaucasia belong to unconventional anisotropic reservoir rocks of VTI symmetry. Because the rocks have extremely low permeability, hydraulic fracturing is commonly used to increase hydrocarbon production. To develop an appropriate design for hydraulic fracturing, knowledge of geomechanical characteristics is required, which includes two Young moduli and three Poisson ratios for the VTI medium. In this paper, we present correlations between the geomechanical characteristics and other parameters that can be measured at the log or seismic scale. The correlations are derived on the base of the rock physics model previously developed by the authors from log data available for a well penetrating these rocks. It is shown that the Young moduli correlate well with the acoustic impedance (a positive correlation). The Poisson ratio characterizing the vertical-to-horizontal strain exhibits a negative correlation with the shear impedance whereas the other two Poisson ratios characterizing the horizontal-to-vertical and horizontal-to-horizontal strain are rather stable within each suite but have certain values. A negative correlation between the kerogen content and the Young moduli is revealed for the Khadumsky suite that serves as a pay zone.
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Application of Sm-Nd Isotope Geochemistry for Unconventional Reservoir Characterization (On The Example of Bazhenov Formation)
Authors Y. Yermakov, M. Spasennykh, E. Leushina, E. Kozlova, N. Bogdanovich, A. Voropaev and Y. KostitsynSummaryThe research objective was to analyze the capabilities of Sm-Nd isotope geochemistry for the characterization of source rocks on the example of the Bazhenov Formation. The chosen geological object is a part of the Upper Jurassic deposits in the Northern region of the Bazhenov Formation. Compared to the well-studied Bazhenov cross-section in the central part of Western Siberia, the cross-section in the North region has a more complex structure with interlayering of intervals of different genesis, characterized by different oil generation potential. The comprehensive comparative analysis of the data on the Sm/Nd and143Nd/144Nd with results of the lithological, petrophysical, and geochemical study shown the considerable difference in the sources of inorganic components of different lithological members. Obtained results allowed us to suggest the changes in preferential direction of continental runoff from the East (Eastern Siberia) and the West (Ural) during the period of sedimentation.
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Compositional Kinetics of The Bazhenov Kerogen Thermal Destruction: The Effect of Organic Matter Maturity
Authors Е. Leushina, V. Shirokova, E. Kozlova, V. Polyakov, D. Kalacheva, N. Morozov and M. SpasennykhSummaryThe work is devoted to the experimental study of the compositional kinetics of kerogen thermal transformation to petroleum for 5 samples from the Bazhenov formation (West Siberia Petroleum Basin). Rock samples containing kerogen of different maturity show gradual change of the bulk kinetic spectra shape from nearly symmetric for immature kerogen to asymmetrical for overmature kerogen (constant frequency factor А = 1×1014 s-1 have been used). For compositional spectra calculation, total HC yield was divided to 4 pseudo-components: gas С1-C5, С6, oil С7-С15 and heavy hydrocarbons С16+, derived from results of pyro-GC-TOFMS/FID analyses. For immature sample, percentage of gas in kerogen decomposition products is 35%, parts of С6, С7-С15, C16+ are 7, 42 and 16 %, respectively. Considering samples from immature to overmature, we noticed a decrease of gas and C16+ percent in the products, along with increasing C6. The main products are oil hydrocarbons С7-С15, the maximum in oil window is 49%. The obtained compositional kinetic spectra are used in petroleum system modeling of hydrocarbons generation during geological history. The results could be applied for the simulation of organic matter transformation into oil and gas in the technological process of thermal EOR (steam, supercritical water, high pressure air injection).
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Void Space Formation in The Bazhenov Formation Kerogen During Isothermal Treament in an Open System
Authors T. Karamov, E. Leushina, E. Kozlova, T. Bulatov and M. SpasennykhSummaryPorosity of the Bazhenov Formation rocks is concentrated in two main components: mineral matrix and solid organic matter (kerogen). Since organic matter may occupy up to 50% of the rock volume and the majority of pores are open (connected), this type of porosity can significantly contribute to the total porosity saturated with hydrocarbons. The aim of the study is to investigate the porosity evolution in organic matter (kerogen) of Bazhenov Formation rocks during physical modeling of thermal maturation. Experimental studies of isothermal treatment of the Bazhenov Formation rocks have shown development of new pores in type II kerogen. At a temperature of 390°C single pores with a size of 50–70 nm were observed. Higher temperatures (400–420 ° C) resulted in bigger pores with a size of more than 1 micron. These results expand the existing knowledge of the Bazhenov Formation porosity in two aspects. Firstly, they show that the kerogen’s porosity can significantly exceed the intercrystalline porosity in case of high thermal maturation. Secondly, thermal treatment leads not only to kerogen conversion but also to the formation of new pores in organic matter.
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Methodology for Reflecting The Geological Concept of The Structure of Bodies in a Digital 3D Model of The Upper Jurassic Sediments of Western Siberia
Authors O. Kim, V. Nemova, T. Maatuhina and A. PogodaevaSummaryMethodology for Reflecting The Geological Concept of The Structure of Bodies in a Digital 3D Model of The Upper Jurassic Sediments of Western Siberia
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Prediction of The Sweet Spots of Unconventional Shale Reservoir in The Eastern and Central Ciscaucasia Based on Anisotropic Petro-Elastic Modelling and Seismic Interpretation
Authors D. Danko, I. Bayuk, M. Kulapova and V. RyzhkovSummaryThe unconventional shale reservoirs of the Eastern and Central Ciscaucasia have extremely low permeability. Therefore, the sweet spots of study rocks are the intervals with natural fractures and high brittleness values. In such rocks, hydraulic fracturing is commonly used to increase hydrocarbon production. To study unconventional shale reservoirs, it is necessary to develop and use more complex petro-elastic models that allow taking into account the standard measurements of the elastic rock properties and the microstructure of the pore space and the anisotropy parameters. The dynamic brittleness index can be calculated using dynamic Young modulus and Poisson ratio as the results of pre-stack seismic inversion. The seismic geometrical attributes give information about the fractured zone. This work shows how to identify sweet spots using complex analysis of the results of anisotropic petro-elastic modelling and seismic interpretation.
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New Data on Heat flow for Modeling Areas of Hydrocarbon Systems of The Bazhenov and Domanik Formations
Authors Yu. Popov, M. Spasennykh, A. Shakirov, E. Chekhonin, R. Romushkevich, E. Savelev and D. ZagranovskayaSummaryThe new experimental geothermal investigations of hydrocarbon systems of the Bazhenov and Domanik Formations are necessary for basin modeling as previous heat flow data have serious errors caused by drawbacks of traditional methods used for experiments. Two wells drilled in the Bazhenov and Domanik Formations (depth of 3202 and 3827 m correspondingly) were studied with advanced techniques that included the method of thermal core logging for thermal properties determination for 4102 and 1699 core samples correspondingly and a new method of thermal property prediction from standard well-logging data for intervals without coring. The measurements were also performed on as-received, dry and brine-saturated core plugs and in-situ conditions. Influence of technological fissuring was accounted for from variations in thermal conductivity components for different states of core plugs. The equivalent thermal conductivity was determined for different depth intervals taking estimated influence of anisotropy and PT-corrections into account. Detailed data on equilibrium temperature gradient along the wells were used. Essential vertical variations in heat flow along the wells were registered (by 55 and 25% correspondingly) and the terrestrial heat flow values were determined (87.1 and 74.4 W/(mK) correspondingly) that exceed significantly (by 65 and 120%) the averaged data published previously for these territories.
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The Nature of The Anomalous Seismic Pattern of Reflector B in The Classical Structure of The Bazhenov Formation on The Eastern Framing of The Surgut Arch
Authors M.E. Smirnova, I.V. Panchenko and N.N. GatinaSummaryThis paper discusses one of the variations in the structure of the classical type of section of the Bazhenov Formation, which has a non-standard expression on seismic sections. The geophysical expression of such sections is similar to the pattern inherent in the anomalous sections of the Bazhenov Formation: the negative phase of reflector B expands, the negative phase is locally bifurcated, and an independent lenticular positive reflection appears inside. In the zone of bifurcation of the negative phase of reflector B in the well sections, an increased thickness of the Formation is noted, namely, its upper part of the section - 6th band. With a sufficient thickness of 6th band, a two-modal high-amplitude negative reflection is formed due to the change in acoustic properties, first when passing from the Lower Achimov clays to clay silicites of the 6th band and further to silicites composing bands 1–5. The well data demonstrate that the Bazhenov Formation is laterally sustained within this zone. Changes in thickness are relatively smoothly, according with the structural-tectonic plan of the territory. Such a structure of the Formation is due to the redistribution of sedimentary material of 6th band into accommodation spaces on the slope of the Surgut arch.
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Molecular Dynamics Modeling of Kerogen Chemical Structure
Authors V. Shirokova, A. Zhugayevych and M. SpasennykhSummaryThe work is devoted to the reconstruction of Bazhenov kerogen chemical structure. For this purpose, the 4-step workflow was developed. At the first stage, available experimental data (CHNS analysis, pyrolysis, 13C NMR, XPS) was processed. It provided with kerogen structural parameters: relative amounts of elements, types and amounts of heteroatomic functional groups and carbon forms in the structure under study. At the second stage, 3 potential macrofragments were built, their structural parameters and 13C NMR spectra were calculated and compared to the real one. As a result, the most possible macrofragment was chosen for structure modeling. The third stage was related to the preparations of input data for molecular dynamics simulation software. It included creation of several files, containing description of each atom and force field parameters. At the final stage, the molecular dynamics simulation of several copies of selected macrofragment was run. It provided with the equilibrated kerogen model. As a result, the first data on chemical structure of Bazhenov kerogen was obtained. It is expected to be applied for the calculation of kerogen chemical transformation in geological and technological processes.
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Reservoir Model of the Bazhenov High-Carbon Formation
SummaryThe area of reservoirs distribution is controlled by depositional environment of radiolarites, phosphates and biogenic carbonates, as well as the degree of catagenetic transformation, which determines the formation of secondary porosity. The largest pore sizes and the best connectivity in the BHCF are found in reservoirs of the pore-microcavernous type in siliceous and carbonate-siliceous radiolarites at the early and middle stages of catagenesis. At the stages of middle and late catagenesis, pore reservoirs also begin to form in phosphate rocks. The kerogen porosity also makes a large contribution to the volume of void space in late catagenesis. The porosity of already existing siliceous reservoirs increases due to the appearance of pores in kerogen, as well reservoirs in kerogen-rich matrix rocks appear. Reservoirs of fractured and fractured-cavernous type are formed under the influence of hydrothermal fluids and are found in rocks, the transformation of which corresponds to middle mesocatagenesis and higher the stages. Thus, it was shown that the reservoirs in the sections thicken with an increase of catagenetic transformation degree due to the appearance of additional elements of the void space in rocks with different composition that compose the BHCF.
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Compound-Specific Stable Isotope Composition of Hydrocarbons as a Tool in Petroleum Exploration
More LessSummaryCompound-specific isotope analysis (CSIA) of individual hydrocarbons is a powerful tool in petroleum exploration. When integrated with other organic geochemical methodologies it can provide evidence of fluid histories including source, maturity, charge history and reservoir processes that can support field development planning and exploration efforts. The purpose of this presentation is to provide a review of the methodology used for generating carbon and hydrogen isotope data for petroleum hydrocarbons. The talk will cover the key factors that control stable carbon and hydrogen isotope compositions of n-alkanes and related compounds in sedimentary and petroleum systems and review current and future applications of this methodology for petroleum exploration. In addition, the presentation will give examples of basin specific case studies that demonstrate the usefulness of CSIA when addressing either particular aspects of petroleum exploration (e.g., charge evaluation, source rock-oil correlation, and investigation of maturity and in-reservoir processes) or when this technique is used to corroborate interpretations from integrated petroleum systems analysis, providing unique insights, which may not be revealed when using other methods. CSIA of petroleum hydrocarbons can provide crucial data to strengthen petroleum systems concepts from generation and expulsion of fluids from source rock, to charge history, connectivity, and in-reservoir processes.
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Pyrite Morphology and Sulfur Isotope Composition in The Bazhenov Formation of West Siberia
Authors E. Idrisova, T. Karamov, A. Voropaev, R. Gabitov, N. Bogdanovich and M. SpasennykhSummaryPyrite morphology and sulfur isotope composition may serve as indicators of redox conditions changes during sedimentation process. Redox conditions, in turn, affect the accumulation and transformation of organic matter in the rocks. Pyrite morphology was studied with scanning electron microscopy (SEM). Sulfur isotope composition was measured with two methods: isotope ratio mass spectrometry (IRMS) and secondary isotope ratio mass spectrometry (SIMS). The studied rock samples of the Bazhenov Formation contain various pyrite types: small (5–10 μm) and large (10–30 μm ) framboids, fine-crystalline (1–2 μm) aggregates and large euhedral crystals (20–50 μm). Small framboids and fine-crystalline pyrite have isotopically light sulfur, δ34S varies in the range from -55 to -20 ‰ CDT. Large framboids and large idiomorphic crystals contain more isotopically heavy sulfur (up to 25 ‰ CDT). The abundance of small framboids indicates anoxic or euxinic sedimentation conditions that control OM’s accumulation and preservation. Large framboids and large pyrite crystals in the sediments indicate the suboxic conditions of sedimentation and possible oxidation of OM during early diagenesis.
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Comparison of The Pore Space Transformation and Newly Generated Hydrocarbons Composition in Result of Thermal Heating of Domanic and Bazhenov Rock Formations
Authors D. Gafurova, A. Kalmykov, D. Korost, M. Tikhonova, O. Vidishcheva, A. Bychkov and G. KalmykovSummaryThis paper presents the results of organic matter transformation in the rocks of the Jurassic high-carbon formation and Domanik high-carbon formation study. The uniqueness of these deposits lies in the fact that they are both a proven highly productive oil source stratum and can contain a significant amount of hydrocarbons that have not yet been emigrated and / or generated. This gives the right to consider these deposits as a single non-structural hydrocarbon reservoir, from which part of the hydrocarbons left and migrated into structural traps, and part remained and represents undiscovered hydrocarbon resources. The main problem in such rocks is the difficulty of extracting hydrocarbons, they are located in a low porous matrix. In addition, the organic matter itself acts as a sorbent and hinders their emigration. Also, hydrocarbons can be found in closed and sealed pores. Investigation of the transformation of organic matter, pore space and the composition of released synthetic hydrocarbon compounds in high-carbon rocks in the future may contribute to the selection of optimal technologies for the development of unconventional oil and gas reservoirs.
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Practical Application of Chemostratigraphy and Lithochemistry Methods in The Study of Oil Bearing Black Shale
Authors I. Panchenko, P. Kulikov and R. GaripovSummaryMost of the well-known oil-bearing black shales are united by the fact that they contain abnormally high contents of a number of chemical elements (U, S, Fe, Mg, P, Cu, Zn, Mo, V, Ni, Ba, As, etc.). The study of variations in the content and ratios of these elements makes it possible to obtain an increase in geological data on the genesis and properties of rocks. The paper shows how the application of the methods of lithochemistry and chemostratigraphy makes it possible to detail the sectional layering and identify promising hydrocarbon intervals in them. On the examples of the siliceous Bazhenov Formation of Western Siberia, the carbonate Domanic Formations of the Russian Plate and the Kuma Formation of the Ciscaucasia, and clayey Khadum Formation of the Ciscaucasia, the most informative modular chemical parameters are shown for the analysis of carbonate content ((Ca+Mg)/Al, Sr/Ca, Mg/Ca) and clay content (Mg/Ca, (Al+K)/(Ca+Mg+Si), Zr/Al) of the section, terrigenous material input (Zr/Al, Si/Al, Ba/Al, S/(Rb+Zr)), bioproductivity (P/Al, Mo/Al, S/(Rb+Zr), Si/Al) and fluctuations of anoxic events (Mo/Mn, Mn/Al) in the paleobasin.
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Assessment of The Hydrocarbon Potential of The Domanik Deposits of The TPP on The Basis of Quantitative Models of Generation and Assessment of The Saturation of The Pore Space
Authors O. M. Prischepa, Yu. V. Nefedov and A. H. IbatullinSummaryOne of the discussed issues concerning the development of the resource base of hydrocarbons in recent years is the study of ways of involving in the development of industrial clusters associated with high carbon shale complexes that are widespread in Russia. Interest in them is supported by the system of benefits provided by the Government of the Russian Federation for low-permeability strata and special preferential conditions for conducting geological exploration provided in recent years. An important effect was also achieved by the development of a methodology for estimating reserves and placing on the state balance of reserves of a group of fields with oil deposits in the domanik deposits of the Volga-Ural OGP. This assessment of potential carbon formations of the Russian Federation continues to be a subject of scientific research without an application component, because of its inapplicability to select as the most important areas for exploration and possibilities of use in the study of investments. The uncertainty is related to the assessment of possible production levels with an unclear correlation between development technologies, filtration and reservoir properties, and the potential of high-carbon strata. There are several approaches to assessing the resources of hydrocarbon accumulations confined to low-pore and low-permeable strata of oil and gas source formations. In this study, we discuss two approaches that allowed us to assess the potential of the main high-carbon strata common in Russia.
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