GEOLOGICAL STRUCTURE OF THE SURFACE OF THE PALEOZOIC FOLDED BASE OF THE WEST OF THE TURAN PLATFORM

2021 ◽  
Vol 82 (3) ◽  
pp. 19-26
Author(s):  
POPKOV VASILY I. ◽  

The surface of the folded base of the platforms is an important geological boundary separating rock complexes formed in different geodynamic settings and characterized by different physical properties, which largely determine the patterns of formation of minerals in them. Therefore, determining the depth of its occurrence and morphology is not only theoretical, but also practical. Despite many years of studying the foundation of the west of the Turan Platform, there is no unity among geologists and geophysicists in their ideas about its structure, depth of occurrence and surface structure. In this regard, the aim of the work is to build a structural map of the surface of the foundation of the west of the Turan plate, to identify the main tectonic structures and their morphology. The construction is based on a comprehensive analysis of drilling materials and geophysical data. When drawing up the structural map, all the currently available geological and geophysical material was used, including data from drilling, gravity and magnetic surveys, and seismic surveys of various modifications, which made it possible to perform fairly detailed and reliable constructions. The article provides a detailed description of the surface structure of the folded base of the west Turan platform. The obtained results can be used in solving the issues of oil and gas potential of the studied territory. The folded base of the western Turan plate is a heterogeneous and heterochronous formation, differentiated by the depth of occurrence, which allows for morphostructural zoning of its surface.

2017 ◽  
pp. 58-66 ◽  
Author(s):  
A. B. Tugareva ◽  
G. A. Chernova ◽  
N. P. Yakovleva ◽  
M. L. Moroz

In the presented work the features of the geological structure and oil and gas potential of the pre-Jurassic basement rocks are discussed. In the sediments of the oil and gas bearing horizon of zone of contact five types of reservoir rocks are distinguished. The greatest prospects for oil and gas potential are associated with the carbonate depositions of the Middle Paleozoic and effusive of the medium-acidic composition of the Permian-Triassic and Triassic age. From these deposits in the territory of the district the maximum oil inflows were received. 15 promising zones of oil and gas accumulation in the deposits of the oil and gas bearing horizon of zone of contact were distinguished, three of which are poorly studied by drilling and one zone (Predeniseyskaya) is in the Paleozoic oil and gas complex.


2020 ◽  
Vol 245 ◽  
pp. 505-512
Author(s):  
Evgeny Gusev ◽  
Alexey Krylov ◽  
Dmitry Urvantsev ◽  
Yury Goremykin ◽  
Petr Krynitsky

Until recently, the North of the Kara Shelf was completely unexplored by seismic methods. Seismic and seismo-acoustic data that have appeared in recent years have made it possible to decipher features of the regional geological structure. This study solves the urgent problem of determining the prospects for the oil and gas potential of the North Kara sedimentary basin. The relevance of the research is associated with determining the prospects of the oil and gas potential of the North Kara sedimentary basin. The aim of the study is to clarify the age of the reflecting horizons using data on the geology of the island, as well as to determine the tectonic position of the sedimentary cover and basement structures in the north of the Kara shelf. The sedimentary cover is divided into three structural levels: Cambrian-Devonian, Middle Carboniferous-Cretaceous, Miocene-Quarter. The Cambrian-Devonian complex fills the deep troughs of the North Kara shelf. The most noticeable discontinuity is the base of Carboniferous-Permian rocks, lying on the eroded surface of folded Silurian-Devonian seismic complexes. The blanket-like plate part of the cover is composed of thin Carbon-Quarter complexes. The authors came to the conclusion that the fold structures of the Taimyr-Severozemelskiy fold belt gradually degenerate towards the Kara sedimentary basin and towards the continental slope of the Eurasian basin of the Arctic Ocean. A chain of narrow uplifts within the seabed relief, which correspond to narrow anticlines is traced to the West of the Severnaya Zemlya islands. Paleozoic rocks have subhorizontal bedding further to the West, within the Kara shelf. Mesozoic folding in the North of the Kara Sea is expressed exclusively in a weak activation of movements along faults. At the neotectonic stage, the shelf near Severnaya Zemlya was raised and the Mesozoic complexes were eroded. The modern seismic activity of the North Zemlya shelf is associated with the ongoing formation of the continental margin.


Author(s):  
Sh. Qiu ◽  
N. A. Kasyanova

Background. In terms of oil and gas, the territory of the Chezhen depression has been studied insufficiently compared to the neighbouring same-range depressions. These depressions complicate the first-order Jiyang depression, geographically coinciding with the largest Shengli hydrocarbon field. In recent years, much geological and geophysical information about the oil geologyof the Chezhen depression has been accumulated, which allows its prospecting oil and gas potential to be assessed.Aim. To reveal regular features of the geological structure and location of oil deposits in the Chezhen depression in order to support the prospecting and exploration work within the Chezhen block of the Shengli field.Materials and methods. A comprehensive analysis of literature data and collected materials was conducted. A historical and geodynamic study of the evolution of the studied area according to literature data was carried out, along with an analysis of the most recent geological and geophysical information and exploration data based on the materials of the “Shengli AKOO Sinopek” oil company. The analysis was based on the data from 52 drilling wells and the results of seismic surveys performed in the central part of the Chezhen depression.Results. Specific features of the block geological structure of the area under study were established, which formed under the repeated influence of large-scale horizontal tectonic movements occurring at different periods of geological history. The role of the most recent fault system in the modern spatial distribution of oil deposits was determined.Conclusions. Our studies demonstrate a great prospecting potential of the Chezhen depression territory, where the discovery of new industrial oil deposits can be expected.


2020 ◽  
Vol 1 (2) ◽  
pp. 7-19
Author(s):  
Vladimir Sergeevich PONOMAREV ◽  
◽  
Kirill Svyatoslavich IVANOV ◽  
Yuriy Viktorovich EROKHIN ◽  
◽  
...  

Relevance of the work. The Western Siberian megabasin is the main source of oil and gas in Russia. Therefore, the study of geological structure and evolution of the development of sedimentary cover rock complexes and the basement of the region is important for estimating the oil and gas potential of this vast territory. The object of this paperis the mineralogical and petro-geochemical study of volcanites from the pre-Jurassic basement of the Lakyuganskaya area (well no. 101) of the Longyugansk exploration acreage within the territory of the Nadym megadepression of the Western Siberian megabasin. Scope of work. This work can be useful when constructing geological maps of the basement of the northern part of the Western Siberian Plate. Results and conclusions. We have studied and described the mineralogy of strongly altered volcanites from the pre-Jurassic basement of the Lakyugansk area (well no. 101) of the Western Siberian Plate. According to chemical composition, the studied volcanites are classified as moderate and high potassic basalts, andesite-basalts and andesites. The rocks were subjected to significant secondary changes in the mineral composition, such as greenschist metamorphism and propylitization. Only titanomagnetite has been preserved from primary minerals in volcanites; all other minerals were subjected to changes. In general, we have determined the following minerals – albite, clinochlore, titanite, calcite, goethite, titanomagnetite (magnetite, ulvospinel), fluorapatite, and rutile. For the first time, ferroaluminoceladonite (dioctahedral mica) and three relatively rare secondary copper sulfides – spionkopite, yarrowite, and geerite – were identified and described in basalts from the basement of Western Siberia. Sulfide coppery mineralization in the studied basalts was due to overlapped propylization processes. The rocks have features of volcanites of island arcs, as well as evidence of calc-alkali and intraplate basalts. The petrological and geochemical characteristics of the studied volcanites are similar to basalts composing the Koltogorsko-Urengoysky rift of the Western Siberian Plate.


Author(s):  
H.O. Zhuchenko ◽  
I.R. Mykhailiv ◽  
N.V. Hoptariova ◽  
H.D. Horvanko

The topicality of the research is determined by the detailed study of the peculiarities of the geological structure of Boryslav-Pokuttia zone of the Precarpathian deflection, in particular of local structural forms as probable traps for oil and gas, for reliable prediction of the oil and gas potential of the subsoil. Boryslav-Pokuttia zone of the Precarpathian deflection refers to one of the oldest oil and gas producing regions in Ukraine. Its hydrocarbon potential is far from being exhausted. The complex block structure of Boryslav-Pokuttia zone requires the development of specific methods for conducting oil and gas prospecting. In this regard, determining the distribution nature of the local structures and specifying the peculiarities of their morphological forms in the area under investigation are of great importance. The issue of tracing tectonic disturbances and determining their screening ability which determines the possible existence of hydrocarbon deposits remains to be an urgent matter. Solving these issues will significantly improve the geological efficiency of prospecting and exploration in the areas of Boryslav-Pokuttia zone. At the modern stage of the Earth sciences development computer processing of geological data is widely used.Therefore, along with the traditional approach to describing structures as potential traps for oil and gas, it isnecessary to analyze their quantitative (numerical) parameters. It gives a possibility to confirm the stablished regularities more reasonably. Handling large array of quantitative indicators of local structures and the dependencies established among them makes it possible to simulate the processes that formed them and to determine the regularities of their distribution. The most important scientific and practical results include: the quantitative indicators ranking of the local structures of Boryslav-Pokuttia zone (the ranking contains four groups of structures classified according to their morphological texture); the investigated conditions for the formation of morphological varieties of local structures and the character of the distribution of tectonic deformations in them. The results of geological and mathematical simulation according to a complex of quantitative indicators help to state that local structures with certain morphological features, which are revealed to various extent in their deformations, are formed by tectonic movements of different magnitude and direction and are described by the numerical parameters peculiar only to them. Investigating the distribution of tectonic stresses and deformations, which can be estimated in quantitative indicators, will contribute to a more reliable prediction of the oil and gas potential of the subsoil. In its turn, it will improve significantly the geological performance of oil and gas prospecting in the areas of BoryslavPokuttia zone of the Precarpathian deflection.


2021 ◽  
Vol 133 (2) ◽  
pp. 27-30
Author(s):  
D. A. Kobylinskiy ◽  

The work is devoted to the development of geochemical criteria for determining the nature of saturation for deep-adsorbed gases in the core. As the object of investigation used the core material selected in the fields in the Nadym-Pyrskoy oil and gas field. In each sample, 72 components were determined, namely, hydrocarbons of different material groups: normal, branched, polycyclic, and aromatic compounds from butane to dodecane. With respect to the quantitative distribution and correlation among the components, qualitative geochemical indicators of sediment productivity have been developed. The saturation character established by the criteria of deep-adsorbed gases was confirmed by the test results. In this regard, this research method significantly increases the effectiveness of diagnostics of prospective deposits, the application of which is relevant in the territory of the West Siberian oil and gas basin, especially when studying deep-submerged deposits of complex geological structure.


2017 ◽  
pp. 25-34
Author(s):  
G. .. Mukher ◽  
S. F. Kulagina ◽  
A. V. Goryachev ◽  
E. A. Pakhomova ◽  
A. A. Gladyshev

The features of the geological structure and oil and gas potential of the Bazhenov-Abalak oil and gas complex are discussed. Based on new geological and seismic data, using an integrated approach, the zones of distribution and the boundaries of thinning out of silty sand reservoir rocks of Vogulkinskaya strata were mapped, four traps and two zones (Ourinskaya, Eastern Tolumskaya), which are perspective for hydrocarbon deposits search, were distinguished. In Bazhenov horizon, the zones of development of anomalous sections and bituminous sediments were mapped, laying above Bazhenov formation, which are perspective for hydrocarbon deposits search. Recommendations for further exploration are given.


Author(s):  
Vladimir Sergeevich PONOMAREV ◽  
◽  
Yuriy Viktorovich EROKHIN ◽  
Kirill Svyatoslavich IVANOV ◽  
Nadezhda Nikolaevna FARRAKHOVA ◽  
...  

Relevance of the work. The Arctic part of the West Siberian megabasin is the main source of oil and gas in Russia, therefore, the study of the geological structure of this region is extremely important. Recently, Russia has lodged an application to extend its territory in the Arctic Ocean along the ridges that stretch from the continental shelf. Unfortunately, at the same time, we know little about the geological structure of the Arctic in the region of Western Siberia, where the thickness of the sedimentary cover is very high (about 3–4 km), therefore, the study of the basement of the Yamal Peninsula seems to be extremely urgent. The purpose of this work is mineralogical, petrological and geochemical study of dolerites from the pre-Jurassic basement of the Bovanenkovskaya area (well No. 114) within the territory of the gas condensate field of the same name, located in the western part of the Yamal Peninsula. Scope of the work. This work can be useful in constructing geological maps of the pre-Jurassic basement of the Yamal Peninsula. Results and conclusions. We have studied the mineralogical and geochemical features of dolerites from the pre-Jurassic basement of the Bovanenkovskaya area (well No. 114, sampling depth – 3210 m) of the West Siberian megabasin. The mineralogy of the rocks is represented by augite, diopside, albite, magnesian chamosite, ferrous hornblende, calcite, siderite, dolomite, anorthoclase, grossular, zeolite (gmelenite-K), pyrite, chalcopyrite, and rare lead chloride – cotunnite. The rocks underwent minor transformations in the conditions of the lower greenschist metamorphism, as well as secondary alterations in the form of superimposed propylitization. As a result of this low-temperature metasomatic process, zeolite, carbonate (calcite, dolomite, and siderite) and sulfide mineralization composed of pyrite and chalcopyrite, as well as cotunnite, which apparently replaced the dissemination of galena, were formed in the rock. Judging by geological position of the region, these dolerites are most likely formed at shallow depths during continental rifting. Remelting of the Paleozoic island arc substrate during the Early Triassic rifting and volcanism provided some closeness to the island arc trend in the geochemical features of these rift volcanics.


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