M. Delengov, N. Fadeeva, M. Bolshakova, E. Kozlova
To get properties and characteristics of oil and gas source rocks and for other geological aims, geologists analyzes core samples from wells and outcrop samples. But we should probably somehow correct geochemical source rock properties data we get on outcrop samples, because organic matter could change significantly due to oxidizing and weathering. This problem is very important but poorly developed in modern publications, so it attracted our interest and led to this investigation. Published information on the organic matter weathering which change it’s content and quality in sedimentary rocks is collected and summarized in this article. The changes of the kerogen (isolated from the mineral matrix) elemental composition during its long-term storage are presented. We compared the results we get in laboratory and results of other authors who dealt with natural changes of organic matter in outcrops. An attempt to interpret the results obtained from the point of view of hypergene changes in OM was made. Uncertainties that require further study and development are indicated. This work is the first step to better understanding of weathering effect on organic matter content and properties – question of great importance for making adequate oil and gas prospects estimations. This study continues the work of our foregoers and Teachers – geochemists of the Petroleum Geology Department of Lomonosov Moscow State University: N.B. Vassoevich, Yu.I. Korchagina, O.A. Radchenko, V.A. Uspensky, I.E. Leifman, A.N. Guseva, O.K. Bazhenova, T.A. Kiryukhina.
{"title":"About the weathering effect on sedimentary rocks organic matter","authors":"M. Delengov, N. Fadeeva, M. Bolshakova, E. Kozlova","doi":"10.18599/grs.2022.2.7","DOIUrl":"https://doi.org/10.18599/grs.2022.2.7","url":null,"abstract":"To get properties and characteristics of oil and gas source rocks and for other geological aims, geologists analyzes core samples from wells and outcrop samples. But we should probably somehow correct geochemical source rock properties data we get on outcrop samples, because organic matter could change significantly due to oxidizing and weathering. This problem is very important but poorly developed in modern publications, so it attracted our interest and led to this investigation. Published information on the organic matter weathering which change it’s content and quality in sedimentary rocks is collected and summarized in this article. The changes of the kerogen (isolated from the mineral matrix) elemental composition during its long-term storage are presented. \u0000 \u0000We compared the results we get in laboratory and results of other authors who dealt with natural changes of organic matter in outcrops. An attempt to interpret the results obtained from the point of view of hypergene changes in OM was made. Uncertainties that require further study and development are indicated. This work is the first step to better understanding of weathering effect on organic matter content and properties – question of great importance for making adequate oil and gas prospects estimations.\u0000\u0000This study continues the work of our foregoers and Teachers – geochemists of the Petroleum Geology Department of Lomonosov Moscow State University: N.B. Vassoevich, Yu.I. Korchagina, O.A. Radchenko, V.A. Uspensky, I.E. Leifman, A.N. Guseva, O.K. Bazhenova, T.A. Kiryukhina.","PeriodicalId":43752,"journal":{"name":"Georesursy","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47766434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Chupakhina, N. I. Korobova, G. Kalmykov, A. Zavyalova, M. Karpushin, K. Radchenko
Domanic deposits have already been studied in sufficient details. Various aspects of their study were described previosly in many works, but so far, these deposits have been considered mainly as source rocks. Domanic deposits are distributed in a wide stratigraphic range from the Middle Frasnian of the Late Devonian to the Tournaisian of the Early Carboniferous. In this paper, domanic formation is considered as an unconventional reservoir. Due to the complex and heterogeneous structure of rocks, their uneven saturation with organic matter and low porosity values, the methodology for assessing reservoir properties is at a low stage of production. An integrated study of the void space in such deposits, including macro- and microdescription of the core, analytical studies, makes it possible to predict zones with best quality of reservoirs and helped successfullу produce such deposits. In the section of domanic formation were identified the main lithotypes and characterized of each of them. Comparison of the types of void space identified in thin sections and reservoir properties made it possible to classify the main types of reservoirs and assess their quality.
{"title":"Different types of void space and quality of unconventional reservoirs in the Upper Devonian domanic high-carbon deposits of Mukhanovo-Erokhovsky trough (Volga-Ural basin)","authors":"V. Chupakhina, N. I. Korobova, G. Kalmykov, A. Zavyalova, M. Karpushin, K. Radchenko","doi":"10.18599/grs.2022.2.14","DOIUrl":"https://doi.org/10.18599/grs.2022.2.14","url":null,"abstract":"Domanic deposits have already been studied in sufficient details. Various aspects of their study were described previosly in many works, but so far, these deposits have been considered mainly as source rocks. Domanic deposits are distributed in a wide stratigraphic range from the Middle Frasnian of the Late Devonian to the Tournaisian of the Early Carboniferous. In this paper, domanic formation is considered as an unconventional reservoir. Due to the complex and heterogeneous structure of rocks, their uneven saturation with organic matter and low porosity values, the methodology for assessing reservoir properties is at a low stage of production. An integrated study of the void space in such deposits, including macro- and microdescription of the core, analytical studies, makes it possible to predict zones with best quality of reservoirs and helped successfullу produce such deposits. In the section of domanic formation were identified the main lithotypes and characterized of each of them. Comparison of the types of void space identified in thin sections and reservoir properties made it possible to classify the main types of reservoirs and assess their quality.","PeriodicalId":43752,"journal":{"name":"Georesursy","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48258286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Pronina, Anastasia P. Vaitekhovich, A. Kalmykov, D. A. Marunova
The question of the correct terminology is highly relevant, since researchers should understand one another in communication with specialists in different branches of geology. An overview of the terms already existing in the English-speaking world for describing oil-prone macerals, such as alginite, bituminite, bitumen, solid bitumen, pyrobitumen, oil, was presented, and it is more convenient to combine all zooclasts into bioclasts, since it is not always possible to determine whether the remains belong to the animal or plant world. Particular difficulties emerged with the term “bitumen”, which in Russian has two meanings. Increasingly, the films between mineral grains can be named both bitumen and oil. It was also suggested to divide bituminite in pre-mature bituminite, mature bituminite and post-mature bituminite in order to emphasize the features of those transformations that occurred with the initial organic matter during thermal maturity. Due to the fact that in the process of thermal maturity, the reactive part of kerogen = bituminite will transform into a liquid and gas, its solid part (“residual organic matter”) was suggested to be called solid bitumen or pyrobitumen.
{"title":"The significance of the macerals identification for understanding and study the transformation processes of organic matter in source rocks","authors":"N. Pronina, Anastasia P. Vaitekhovich, A. Kalmykov, D. A. Marunova","doi":"10.18599/grs.2022.2.6","DOIUrl":"https://doi.org/10.18599/grs.2022.2.6","url":null,"abstract":"The question of the correct terminology is highly relevant, since researchers should understand one another in communication with specialists in different branches of geology. An overview of the terms already existing in the English-speaking world for describing oil-prone macerals, such as alginite, bituminite, bitumen, solid bitumen, pyrobitumen, oil, was presented, and it is more convenient to combine all zooclasts into bioclasts, since it is not always possible to determine whether the remains belong to the animal or plant world. Particular difficulties emerged with the term “bitumen”, which in Russian has two meanings. Increasingly, the films between mineral grains can be named both bitumen and oil. It was also suggested to divide bituminite in pre-mature bituminite, mature bituminite and post-mature bituminite in order to emphasize the features of those transformations that occurred with the initial organic matter during thermal maturity. Due to the fact that in the process of thermal maturity, the reactive part of kerogen = bituminite will transform into a liquid and gas, its solid part (“residual organic matter”) was suggested to be called solid bitumen or pyrobitumen.","PeriodicalId":43752,"journal":{"name":"Georesursy","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44086746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article is devoted to the 120th anniversary of Nikolay Bronislavovich Vassoevich (1902–1981) – a famous petroleum geologist, professor, corresponding member of the USSR Academy of Sciences. The article recalls his significant achievements in the field of fundamental geology. The first and main work in this field was his monograph on the methodology for studying the sedimentation cyclicity of flysch strata (1948), with the continuation of the topic in the next book, published in 1951. The scientific heritage of N.B. Vassoevich, who headed the Petroleum Geology Department of Lomonosov Moscow State University in 1963–1981, is preserved and developed in the modern educational and scientific activities of this Department. Teachers, staff and students with deep gratitude and respect honor the memory of N.B. Vassoevich, using his methodological recommendations on sedimentation cyclicity both in the training course of lithofacial analysis and applied in practical work in the study of oil and gas bearing strata of sedimentary rock basins. A huge role in the development of the terminology of this theory is associated with the development of the conceptual base of this geological direction. Professor N.B. Vassoevich had invested continuous work on the creation of systematic and logical classifications according to the composition, structure, genesis and hierarchy of geological sedimentary bodies that make up oil and gas bearing rock complexes.
{"title":"The theory of sedimentation cyclicity of N.B. Vassoevich in the educational and scientific activities of the Petroleum Geology Department of Lomonosov Moscow State University in the XXI century","authors":"E. Karnyushina","doi":"10.18599/grs.2022.2.3","DOIUrl":"https://doi.org/10.18599/grs.2022.2.3","url":null,"abstract":"The article is devoted to the 120th anniversary of Nikolay Bronislavovich Vassoevich (1902–1981) – a famous petroleum geologist, professor, corresponding member of the USSR Academy of Sciences. The article recalls his significant achievements in the field of fundamental geology. The first and main work in this field was his monograph on the methodology for studying the sedimentation cyclicity of flysch strata (1948), with the continuation of the topic in the next book, published in 1951. The scientific heritage of N.B. Vassoevich, who headed the Petroleum Geology Department of Lomonosov Moscow State University in 1963–1981, is preserved and developed in the modern educational and scientific activities of this Department. Teachers, staff and students with deep gratitude and respect honor the memory of N.B. Vassoevich, using his methodological recommendations on sedimentation cyclicity both in the training course of lithofacial analysis and applied in practical work in the study of oil and gas bearing strata of sedimentary rock basins. A huge role in the development of the terminology of this theory is associated with the development of the conceptual base of this geological direction. Professor N.B. Vassoevich had invested continuous work on the creation of systematic and logical classifications according to the composition, structure, genesis and hierarchy of geological sedimentary bodies that make up oil and gas bearing rock complexes.","PeriodicalId":43752,"journal":{"name":"Georesursy","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46687052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"To the 110th anniversary of my mentor, professor of the Lomonosov Moscow State University Igor Vladimirovich Vysotsky","authors":"E. Ablya","doi":"10.18599/grs.2022.2.4","DOIUrl":"https://doi.org/10.18599/grs.2022.2.4","url":null,"abstract":"","PeriodicalId":43752,"journal":{"name":"Georesursy","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44723903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. K. Komkov, A. Mordasova, M. Dakhnova, M. Bolshakova, S. Mozhegova, N. Pronina
The article is devoted to the variation of generation potential of the Lower-Middle Jurassic organic matter in the Karabash area (South-Western part of the West Siberian basin) depending on facies and sedimentary cyclisity. Based on geochemical and lithological core studies, specific geochemical features of organic matter established for main facies groups of Early-Middle Jurassic in the study area. The best generation potential inherent in deposits of swamps, swampy floodplains and tidal plains. These facies groups characterized by predominance of the continental organic matter and considered to gas source rocks. However, macerals composition, kinetic spectra and biomarker analysis show the presence also of marine organic matter. Some facies groups, such as flooded swamps and swampy floodplains has potential to generate hydrocarbons due to preservation of liptinites with high hydrogen index. Cyclic analysis with basics of sequence stratigraphy of the continental deposits allow tracing the correlation between generation potential and relative sea level changes.
{"title":"Conditions of sedimentation and distribution of organic matter in the Lower-Middle Jurassic complex of the South-Western part of the West Siberian oil and gas basin","authors":"I. K. Komkov, A. Mordasova, M. Dakhnova, M. Bolshakova, S. Mozhegova, N. Pronina","doi":"10.18599/grs.2022.2.15","DOIUrl":"https://doi.org/10.18599/grs.2022.2.15","url":null,"abstract":"The article is devoted to the variation of generation potential of the Lower-Middle Jurassic organic matter in the Karabash area (South-Western part of the West Siberian basin) depending on facies and sedimentary cyclisity. Based on geochemical and lithological core studies, specific geochemical features of organic matter established for main facies groups of Early-Middle Jurassic in the study area. The best generation potential inherent in deposits of swamps, swampy floodplains and tidal plains. These facies groups characterized by predominance of the continental organic matter and considered to gas source rocks. However, macerals composition, kinetic spectra and biomarker analysis show the presence also of marine organic matter. Some facies groups, such as flooded swamps and swampy floodplains has potential to generate hydrocarbons due to preservation of liptinites with high hydrogen index. Cyclic analysis with basics of sequence stratigraphy of the continental deposits allow tracing the correlation between generation potential and relative sea level changes.","PeriodicalId":43752,"journal":{"name":"Georesursy","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48688069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Karpushin, A. Stoupakova, A. Zavyalova, Vitalia V. Chupakhina, A. Suslova, K. Radchenko
The paper describes the structure and depositional conditions of a domanicoid high-carbon formation (HCF) in the central part of the Volga-Ural oil and gas basin. The structure of the HCF depends on the structural relatedness and paleogeographic conditions of the Late Devonian period, where the time of maximum sea level standing within the basin led to deposition of high organic carbon content intervals. The structural-facies zonation of the HCF distribution area is associated with the zone of relatively deep-water depressions, the zone of slopes, highs and the shallow water shelf with numerous bioherm buildups. The boundaries of the zones were determined by the position of large structural elements of the Tatar and Bashkir arches and depressions of the Kama-Kinel system of troughs. These zones differ not only in the distribution of the thickness of HCF deposits, but also in the nature of the distribution of intervals of the section enriched in organic matter. The maximum number of interlayers enriched by organic matter of the siliceous-carbonate rocks is observed in the section of the Frasnian and Famennian deposits within the central part of the Kama-Kinel system of troughs. Numerous of oil shows from the HCF intervals indicate the potential for further study and spotting of promising areas for hard-to-recover hydrocarbon reserves exploration.
{"title":"Geological structure and oil and gas potential of Domanik deposits in the central part of the Volga-Ural oil and gas basin","authors":"M. Karpushin, A. Stoupakova, A. Zavyalova, Vitalia V. Chupakhina, A. Suslova, K. Radchenko","doi":"10.18599/grs.2022.2.13","DOIUrl":"https://doi.org/10.18599/grs.2022.2.13","url":null,"abstract":"The paper describes the structure and depositional conditions of a domanicoid high-carbon formation (HCF) in the central part of the Volga-Ural oil and gas basin. The structure of the HCF depends on the structural relatedness and paleogeographic conditions of the Late Devonian period, where the time of maximum sea level standing within the basin led to deposition of high organic carbon content intervals. The structural-facies zonation of the HCF distribution area is associated with the zone of relatively deep-water depressions, the zone of slopes, highs and the shallow water shelf with numerous bioherm buildups. The boundaries of the zones were determined by the position of large structural elements of the Tatar and Bashkir arches and depressions of the Kama-Kinel system of troughs. These zones differ not only in the distribution of the thickness of HCF deposits, but also in the nature of the distribution of intervals of the section enriched in organic matter. The maximum number of interlayers enriched by organic matter of the siliceous-carbonate rocks is observed in the section of the Frasnian and Famennian deposits within the central part of the Kama-Kinel system of troughs. Numerous of oil shows from the HCF intervals indicate the potential for further study and spotting of promising areas for hard-to-recover hydrocarbon reserves exploration.","PeriodicalId":43752,"journal":{"name":"Georesursy","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49592223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ksenia A. Sitar, B. Georgievskiy, M. Bolshakova, R. Sautkin
Based on comprehensive analysis of geological, geochemical, and paleotectonic settings, the conditions for the formation of Neoproterozoic oil and gas source rocks of the Earth are analyzed. A brief review of oil and gas fields in Eastern Siberia, China, the Middle East, Africa, and Australia is given, with Riphean and Vendian terrigenous and carbonate source rock. An overview of the oil and gas bearing basins of the world and a stratigraphic reference of the Neoproterozoic strata discovered within them, containing proven and suspected oil and gas source rocks, are given. The formation of Neoproterozoic oil and gas source rocks is analyzed in a complex way: simultaneously from the point of view of paleotectonics, paleogeographic and paleoclimatic conditions, paleobiological diversity and geochemical conditions. As part of paleotectonic analysis, the results of plate tectonic reconstructions for the Neoproterozoic stage are presented in accordance with one of the most currently relevant geodynamic models. Paleogeographic events and paleoclimatic conditions are described in the context of the specifics of the formation settings of carbonate-terrigenous oil and gas source rocks. In particular, the reasons for the accumulation of sediments enriched with organic carbon in the interglacial epochs of the Neoproterozoic and possible mechanisms for maintaining conditions favorable for their accumulation are considered. The conditions for the accumulation of oil and gas source rocks are also linked to global paleobiological pre-Phanerozoic events, and the analysis of the geochemical data of rocks makes it possible to characterize and correlate Neoproterozoic oil and gas source rocks on a global scale. On the basis of such a comprehensive assessment, a conclusion was made about fundamentally similar geological conditions for the formation of Neoproterozoic oil and gas source rocks in oil and gas bearing basins.
{"title":"Comprehensive evaluation of Neoproterozoic source rocks formation","authors":"Ksenia A. Sitar, B. Georgievskiy, M. Bolshakova, R. Sautkin","doi":"10.18599/grs.2022.2.8","DOIUrl":"https://doi.org/10.18599/grs.2022.2.8","url":null,"abstract":"Based on comprehensive analysis of geological, geochemical, and paleotectonic settings, the conditions for the formation of Neoproterozoic oil and gas source rocks of the Earth are analyzed. A brief review of oil and gas fields in Eastern Siberia, China, the Middle East, Africa, and Australia is given, with Riphean and Vendian terrigenous and carbonate source rock. An overview of the oil and gas bearing basins of the world and a stratigraphic reference of the Neoproterozoic strata discovered within them, containing proven and suspected oil and gas source rocks, are given.\u0000\u0000The formation of Neoproterozoic oil and gas source rocks is analyzed in a complex way: simultaneously from the point of view of paleotectonics, paleogeographic and paleoclimatic conditions, paleobiological diversity and geochemical conditions. As part of paleotectonic analysis, the results of plate tectonic reconstructions for the Neoproterozoic stage are presented in accordance with one of the most currently relevant geodynamic models. Paleogeographic events and paleoclimatic conditions are described in the context of the specifics of the formation settings of carbonate-terrigenous oil and gas source rocks. In particular, the reasons for the accumulation of sediments enriched with organic carbon in the interglacial epochs of the Neoproterozoic and possible mechanisms for maintaining conditions favorable for their accumulation are considered. The conditions for the accumulation of oil and gas source rocks are also linked to global paleobiological pre-Phanerozoic events, and the analysis of the geochemical data of rocks makes it possible to characterize and correlate Neoproterozoic oil and gas source rocks on a global scale. On the basis of such a comprehensive assessment, a conclusion was made about fundamentally similar geological conditions for the formation of Neoproterozoic oil and gas source rocks in oil and gas bearing basins.","PeriodicalId":43752,"journal":{"name":"Georesursy","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45100543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vladlen I. Sakhnyuk, E. V. Novikov, Alexander M. Sharifullin, Vasiliy S. Belokhin, A. Antonov, Mikhail U. Karpushin, M. Bolshakova, S. Afonin, R. Sautkin, A. Suslova
Nowadays well logging curves are interpreted by geologists who preprocess the data and normalize the curves for this purpose. The preparation process can take a long time, especially when hundreds and thousands of wells are involved. This paper explores the applicability of Machine Learning methods to geology tasks, in particular the problem of lithology interpretation using well-logs, and also reveals the issue of the quality of such predictions in comparison with the interpretation of specialists. The authors of the article deployed three groups of Machine Learning algorithms: Random Forests, Gradient Boosting and Neural Networks, and also developed its own metric that takes into account the geological features of the study area and statistical proximity of lithotypes based on log curves values.
{"title":"Machine learning applications for well-logging interpretation of the Vikulov Formation","authors":"Vladlen I. Sakhnyuk, E. V. Novikov, Alexander M. Sharifullin, Vasiliy S. Belokhin, A. Antonov, Mikhail U. Karpushin, M. Bolshakova, S. Afonin, R. Sautkin, A. Suslova","doi":"10.18599/grs.2022.2.21","DOIUrl":"https://doi.org/10.18599/grs.2022.2.21","url":null,"abstract":"Nowadays well logging curves are interpreted by geologists who preprocess the data and normalize the curves for this purpose. The preparation process can take a long time, especially when hundreds and thousands of wells are involved. This paper explores the applicability of Machine Learning methods to geology tasks, in particular the problem of lithology interpretation using well-logs, and also reveals the issue of the quality of such predictions in comparison with the interpretation of specialists. The authors of the article deployed three groups of Machine Learning algorithms: Random Forests, Gradient Boosting and Neural Networks, and also developed its own metric that takes into account the geological features of the study area and statistical proximity of lithotypes based on log curves values.","PeriodicalId":43752,"journal":{"name":"Georesursy","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45580447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Vidishcheva, G. Akhmanov, E. V. Kislitsyna, A. Mazzini, Anna Yu. Mal’tseva, E. Poludetkina, E. Bakay, I. E. Man’ko, D. Korost, O. Khlystov
The paper presents results of gas-geochemical studies of bottom sediments and petroleum potential assessment of Baikal Rift Basin. During the expeditions of the Class@Baikal project in 2014–2019, gases from the Lake Baikal bottom sediments were analyzed. The results showed a clear difference in chemical and isotopic composition of the seeping gases collected in the northwestern and southeastern parts of the lake. The seepage released from northwest part were relatively enriched by methane and had a low concentration of C2+ compounds. The seepage gases had relatively lighter carbon isotopes composition of CH4 (from -72,7 to -50,1 ‰ VPDB) and the high variability of δ13C in C2H6 (from -65 to -22 ‰ VPDB). The gases released from southeastern part of the lake had an increase in C2+ compounds and had relatively lighter carbon isotopes composition of methane (from –57,2 to –41,0 ‰ VPDB). The carbon isotopes composition of ethane varies from -32 to -25 ‰ VPDB. Asymmetric structure of the Baikal rift basin and various processes of gas migration within it might cause the variations. Diffusive process led to the lighter carbon isotopes composition of the seepage gases from the northwestern part of lake and the gas molecular composition enrichment by methane. Such molecular and isotopic fractionations caused by geochemical processes helps to understand the migration of gas from source rocks to the earth’s surface. Similar geochemical indicators of fractionation should be taken into consideration when assessing oil and gas source rocks and basin potential from gas geochemical studies data.
{"title":"Variations in molecular and isotopes composition of seepage gases in the north-western and south-eastern parts of Lake Baikal","authors":"O. Vidishcheva, G. Akhmanov, E. V. Kislitsyna, A. Mazzini, Anna Yu. Mal’tseva, E. Poludetkina, E. Bakay, I. E. Man’ko, D. Korost, O. Khlystov","doi":"10.18599/grs.2022.2.19","DOIUrl":"https://doi.org/10.18599/grs.2022.2.19","url":null,"abstract":"The paper presents results of gas-geochemical studies of bottom sediments and petroleum potential assessment of Baikal Rift Basin. During the expeditions of the Class@Baikal project in 2014–2019, gases from the Lake Baikal bottom sediments were analyzed. The results showed a clear difference in chemical and isotopic composition of the seeping gases collected in the northwestern and southeastern parts of the lake. The seepage released from northwest part were relatively enriched by methane and had a low concentration of C2+ compounds. The seepage gases had relatively lighter carbon isotopes composition of CH4 (from -72,7 to -50,1 ‰ VPDB) and the high variability of δ13C in C2H6 (from -65 to -22 ‰ VPDB). The gases released from southeastern part of the lake had an increase in C2+ compounds and had relatively lighter carbon isotopes composition of methane (from –57,2 to –41,0 ‰ VPDB). The carbon isotopes composition of ethane varies from -32 to -25 ‰ VPDB. Asymmetric structure of the Baikal rift basin and various processes of gas migration within it might cause the variations. Diffusive process led to the lighter carbon isotopes composition of the seepage gases from the northwestern part of lake and the gas molecular composition enrichment by methane. Such molecular and isotopic fractionations caused by geochemical processes helps to understand the migration of gas from source rocks to the earth’s surface. Similar geochemical indicators of fractionation should be taken into consideration when assessing oil and gas source rocks and basin potential from gas geochemical studies data.","PeriodicalId":43752,"journal":{"name":"Georesursy","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42708865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}