scholarly journals Peculiarities of geological and thermobaric conditions for the gas hydrate deposits occurence in the Black Sea and the prospects for their development

2019 ◽  
Vol 28 (3) ◽  
pp. 395-408
Author(s):  
V. Bondarenko ◽  
K. Sai ◽  
M. Petlovanyi

The actuality has been revealed of the necessity to attract the gas hydrate depos- its of the Black Sea into industrial development as an alternative to traditional gas fields. This should be preceded by the identification and synthesis of geological and thermobaric peculiarities of their existence. It was noted that the gas hydrates formation occurs under certain thermobaric conditions, with the availability of a gas hydrate-forming agent, which is capable of hydrate formation, as well as a sufficient amount of water necessary to start the crystallization process. The gas hydrate accumulation typically does not occur in free space – in sea water, but in the massif of the sea bed rocks. The important role in the process of natural gas hydrates formation is assigned to thermobaric parameters, as well as to the properties and features of the geological environment, in which, actually, the process of hydrate formation and further hydrate accumulation occurs. It was noted that the source of formation and accumulation of the Black Sea gas hydrates is mainly catagenetic (deep) gas, but diagenetic gas also takes part in the process of gas hydrate deposits formation. The main component of natural gas hydrate deposits is methane and its homologs – ethane, propane, isobutane. The analysis has been made of geological and geophysical data and literature materials devoted to the study of the offshore area and the bottom of the Black Sea, as well as to the identification of gas hydrate deposits. It was established that in the offshore area the gas hydrate deposits with a heterogeneous structure dominate, that is, which comprises a certain proportion of aluminosilicate inclusions. It was noted that theBlack Sea bottom sediments, beginning with the depths of 500 – 600 m, are gassy with methane, and a large sea part is favourable for hydrate formation at temperatures of +8...+9oC and pressures from 7 to 20 MPa at different depths. The characteristics of gas hydrate deposits are provided, as well as requirements and aspects with regard to their industrialization and development. It is recommended to use the method of thermal influence on gas hydrate deposits, since, from an ecological point of view, it is the safest method which does not require additional water resources for its implementation, because water intake is carried out directly from the upper sea layers. A new classification of gas hydrate deposits with a heterogeneous structure has been developed, which is based on the content of rocks inclusions in gas hydrate, the classification feature of which is the amount of heat spent on the dissociation process.

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1345
Author(s):  
Oleg Bazaluk ◽  
Kateryna Sai ◽  
Vasyl Lozynskyi ◽  
Mykhailo Petlovanyi ◽  
Pavlo Saik

Ukraine is an energy-dependent country, with less that 50% of its energy consumption fulfilled by its own resources. Natural gas is of paramount importance, especially for industry and society. Therefore, there is an urgent need to search for alternative and potential energy sources, such as gas hydrate deposits in the Black Sea, which can reduce the consumption of imported gas. It is necessary to refine the process parameters of the dissociation of gas hydrate deposits with a heterogeneous structure. The analyzed known geological–geophysical data devoted to the study of the offshore area and the seabed give grounds to assert the existence of a significant amount of hydrate deposits in the Black Sea. An integrated methodological approach is applied, which consists of the development of algorithms for analytical and laboratory studies of gas volumes obtained during the dissociation of deposits with a heterogeneous structure. These data are used for the computer modelling of the dissociation zone in the Surfer-8.0 software package based on the data interpolation method, which uses three methods for calculating the volumes of modelling bodies. A 3D grid-visualization of the studied part of the gas hydrate deposit has been developed. The dissociation zone parameters of gas hydrate deposits with different shares of rock intercalation, that is, the minimum and maximum diameters, have been determined, and the potentially recoverable gas volumes have been assessed. The effective time of the process of gas hydrate deposit dissociation has been substantiated. The obtained research results of the dissociation process of gas hydrate deposits can be used in the development of new technological schemes for gas recovery from the deep-water Black Sea area.


2021 ◽  
Vol 2021 (2) ◽  
pp. 43-55
Author(s):  
Andrey Vitalievich Makagon

The article considers the modern problems and prospects of the development of technologies of transporting the natural gas by sea due to the fact that gas hydrate deposits are found on the bottom of Lake Baikal, the Black Sea, the Caspian Sea and the Okhotsk Sea. It has been stated that despite the proved gas hydrate deposits the fields have not been explored yet. Introducing the technology for transporting gas by sea in gas hydrate form is being substantiated. Comparative analysis of LNG, CNG and NGH technologies for sea transportation of natural gas proved that the transport component of the NGH technological chain has significant advantages over LNG and CNG technologies. The process of converting thermal energy of the ocean has been proposed to use for increasing the energy efficiency of methane production from subsea gas hydrate deposits in the gas hydrate cycle, which can save 10-15% of the produced methane for electricity generation. A schematic and technological solution of a gas production complex is presented, according to which carbon dioxide is introduced into the gas hydrate layer to extract methane from gas hydrates. To improve the kinetics of replacing methane with carbon dioxide in gas hydrates it is proposed to recycle a portion of CO2. Due to the specific and diversified geographic, economic, political and other conditions the conventional technologies for pipeline transportation of gas and LNG cannot fully meet the requirements of gas export and production projects. It has been inferred that NGH technology is most suitable for solving the problem of diversifying natural gas supplies from the Arctic regions, the Black Sea and in the development of offshore gas and oil fields.


2018 ◽  
Vol 27 (2) ◽  
pp. 294-304
Author(s):  
E. Maksymova ◽  
S. Kostrytska

Gas hydrates occurring in the World Ocean are considered as the additional and perspective non-traditional resource of hydrocarbon materials. The proposed classification of deposits as for mining and geological conditions of their occurrence as well as methodological approach to their development and calculation of technological parameters of methane extraction from the World Ocean floor with minimum impact upon the Earth’s hydrosphere is of considerable importance in the context of current studies of new and most prospective source of energy in terms of the available experience gap as for the development of gas hydrate deposits. The approach to search for and explore gas hydrate deposits occurring on and under the World Ocean floor has been suggested; the approach is based upon the regularities of gas hydrate distribution in lithological varieties and geological structures. The necessity to take into consideration the pore space enclosing gas hydrate thicknesses to calculate their reserves has been substantiated. The overview of scientific literature sources summarizingthe results of marine expeditions as well as the analysis of publications of world scientific community dealing with the studies of gas hydrates has made it possible to determine that gas hydrate deposits are associated to the zones of jointing of continental plates and oceanic troughs. In their turn, those zones, due to different genesis, are made up of the corresponding various products of sedimentary rock accumulations. Detailed analysis of the Black Sea floor structure has been performed. Three geomorphological zones have been singled out; basic types of gas-bearing capacity manifestation and methane liberation from the interior have been represented. Quantitative evaluation of methane content in gas hydrate deposits has been given taking into account the detected ones. Data concerning gas-bearing capacity of the Black Sea floor proved by the map of mud volcanoes location within the areas of gas hydrate sampling have been considered. That was the basis to analyze peculiarities of the formation of bottom-sediment gas hydrates basing upon genetic origin of lithological composition of their enclosing rocks and their structures in terms of the Black Sea floor. Relation between the features of the World Ocean floor structure and the distribution of gas hydrate deposits has been determined. Theoretical approach to search for and explore gas hydrate deposits both in the Black Sea and in the World Ocean has been developed and proposed. Interaction between different zones of the World Ocean floor and types of gas hydrate deposits based upon the compositions of their enclosing rock has been shown. Lithological composition of the rocks enclosing gas hydrates has been analyzedin detail. That will make it possible to determine the type of any specific deposit and elaborate technological scheme to open and develop methane-containing gas hydrate deposits.


2018 ◽  
Vol 12 (2) ◽  
pp. 104-115 ◽  
Author(s):  
V Bondarenko ◽  
◽  
K Sai ◽  
K Prokopenko ◽  
D Zhuravlov ◽  
...  

2021 ◽  
Author(s):  
Zheng Liu ◽  
Baojiang Sun ◽  
Zhiyuan Wang ◽  
Jianbo Zhang

Abstract In recent decades, the development of natural gas hydrates has become a research hotspot of scholars all over the world. However, the decomposed gas and water in marine gas hydrate production system may regenerate gas hydrates due to the low-temperature and high-pressure environment in seafloor. In this study, a transient temperature and pressure calculating model was established to predict the risk of hydrate reformation in production pipelines during offshore natural gas hydrate development. Using the proposed model, the region of hydrate reformation in gas hydrate production wells were predicted quantitatively. Meanwhile, the hydrate reformation management strategies through optimization of production design parameters in combination with hydrate inhibitor injection were proposed and discussed in detail. The results indicate that the risk of hydrate reformation is the highest in the drainage pipeline (DP); however, the flow in gas-water mixed transportation and gas production pipelines (MTP and GPP) basically does not satisfy the hydrate formation condition. In the process of production well design, adding additional the EH and ESP can fully eliminate the hydrate reformation risk in the DP without using the hydrate inhibitor.


Geosciences ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 467 ◽  
Author(s):  
Evgeny Chuvilin ◽  
Dinara Davletshina

Favorable thermobaric conditions of hydrate formation and the significant accumulation of methane, ice, and actual data on the presence of gas hydrates in permafrost suggest the possibility of their formation in the pore space of frozen soils at negative temperatures. In addition, today there are several geological models that involve the formation of gas hydrate accumulations in permafrost. To confirm the literature data, the formation of gas hydrates in permafrost saturated with methane has been studied experimentally using natural artificially frozen in the laboratory sand and silt samples, on a specially designed system at temperatures from 0 to −8 °C. The experimental results confirm that pore methane hydrates can form in gas-bearing frozen soils. The kinetics of gas hydrate accumulation in frozen soils was investigated in terms of dependence on the temperature, excess pressure, initial ice content, salinity, and type of soil. The process of hydrate formation in soil samples in time with falling temperature from +2 °C to −8 °C slows down. The fraction of pore ice converted to hydrate increased as the gas pressure exceeded the equilibrium. The optimal ice saturation values (45−65%) at which hydrate accumulation in the porous media is highest were found. The hydrate accumulation is slower in finer-grained sediments and saline soils. The several geological models are presented to substantiate the processes of natural hydrate formation in permafrost at negative temperatures.


2020 ◽  
Vol 81 (3) ◽  
pp. 184-186
Author(s):  
Atanas Vasilev ◽  
Nikola Botoucharov ◽  
Petar Petsinski ◽  
Rositsa Pehlivanova

The aim of this work is to reconstruct the variations of the total gas hydrate (GH) masses of the Danube deep-sea fan after 0.265 Ma BP. The PetroMod™ model developed in GEOMAR, Germany is for basin analysis of the Western Black Sea for 98 Ma. Geological structure is from 2D seismic of the Black Sea consortium “Geology without limits”. Results show a trend for total GH masses decrease after Middle Pleistocene and the role of the GHs as sink and source of methane.


2021 ◽  
Vol 12 (1) ◽  
pp. 312
Author(s):  
Dávid Hečko ◽  
Milan Malcho ◽  
Pavol Mičko ◽  
Nikola Čajová Kantová ◽  
Zuzana Kolková ◽  
...  

For countries with limited access to conventional hydrocarbon gases, methane hydrates have emerged as a potential energy source. In view of the European Union’s requirements to reduce the energy intensity of technological processes and increase energy security, it appears promising to accumulate natural gas and biomethane in the form of hydrate structures and release them if necessary. Storing gas in this form in an energy-efficient manner creates interest in developing and innovating technologies in this area. Hydrates that form in gas pipelines are generated by a more or less random process and are an undesirable phenomenon in gas transportation. In our case, the process implemented in the proposed experimental device is a controlled process, which can generate hydrates in orders of magnitude shorter times compared to the classical methods of generating natural gas hydrates in autoclaves by saturating water only. The recirculation of gas-saturated water has been shown to be the most significant factor in reducing the energy consumption of natural gas hydrate generation. Not only is the energy intensity of generation reduced, but also its generation time. In this paper, a circuit diagram for an experimental device for natural gas hydrate generation is shown with complete description, principle of operation, and measurement methodology. The natural gas hydrate formation process is analyzed using a mathematical model that correlates well with the measured hydrate formation times. Hydrates may become a current challenge in the future and, once verified, may find applications in various fields of technology or industry.


Author(s):  
S. V. Goshovskyi ◽  
Oleksii Zurian

The literature sources dealing with the history of gas hydrate studies and discovery of possible existence of gas hydrate deposits in natural conditions were analyzed. They contain facts proving that within 1966 and 1969 the conditions for formation of hydrates in porous medium were researched at the Department of Gas and Gas Condensate Deposits Development and Exploitation of Gubkin Russian State University of Oil and Gas. The first experiments were set up by the Ukraine-born Yurij F. Makogon, Department Assistant Professor. The results proved possibility of formation and stable existence of gas hydrates in earth’s crust and became a scientific substantiation of natural gas hydrate deposits discovery. In 1969 the exploitation of Messoyakha deposits in Siberia started and it was the first time when the natural gas was derived directly from hydrates. The same year that invention was officially recognized and registered. Following the comprehensive international expert examination the State Committee on Inventions and Findings of the USSR Council of Ministers assumed that the citizens of the USSR Yurij F. Makogon, Andrej A. Trofimuk, Nikolaj V. Cherskij and Viktor G. Vasilev made a discovery described as follows: “Experiments proved previously unknown ability of natural gas to form deposits in the earth’s crust in solid gas hydrate state under definite thermodynamic conditions (Request dated March 19, 1969)”. The authors were presented with diplomas on March 4, 1971. From then onwards the issue of natural gas hydrates existence was widely researched all around the world. In 1985 Yurij F. Makogon became a Professor. Since 1973 he was a head of the gas hydrate laboratory in the All-Russian Scientific Research Institute of Natural Gases and Gas Technologies. Within 1974–1987 he was a head of the gas hydrate laboratory in Oil and Gas Research Institute RAS. In 1992 he was invited by one of the largest universities of the USA to arrange modern laboratory for gas hydrate study. The laboratory was created in the Texas University, USA and in 1995 Yurij Makogon became its head. As far as interest in gas hydrates increases Yurij F. Makogon reports at 27 international congresses and conferences, gives lectures in 45 world leading universities, functions as an academic adviser and participates in different international programs on research and exploitation of gas hydrate deposits in USA, Japan and India. The heritage of the scientist includes 27 patents, eight monographs (four of them were translated and published in the USA and Canada) and more than 270 scientific articles.


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