Influence of the gas extraction pipes material on the intensity of hydrate formation

2017 ◽  
Vol 12 (2) ◽  
pp. 227-231
Author(s):  
R.R. Urazov ◽  
I.A. Chiglintsev ◽  
A.A. Nasyrov

The paper considers the process of formation of hydrate deposits on the walls of the pipeline, in the process of gas extraction from the ”dome-separator“, designed for emergency collection of hydrocarbons on the ocean floor. On the basis of the constructed mathematical model the influence of the kind of tube material on the deposition of gas hydrates is shown.

Author(s):  
Stanislav L. Borodin ◽  
Denis S. Belskikh

Gas hydrates, which contain the largest amount of methane on our planet, are a promising source of natural gas after the depletion of traditional gas fields, the reserves of which are estimated to last about 50 years. Therefore, it is necessary to study the methods for extracting gas from gas hydrates in order to select the best of them and make reasoned technological and engineering decisions in the future. One of these methods is the replacement of methane in its hydrate with carbon dioxide. This work studies the construction of a mathematical model to observe this method. The following process is considered in this article: on one side of a porous reservoir, initially saturated with methane and its hydrate, carbon dioxide is injected; on the opposite side of this reservoir, methane and/or carbon dioxide are extracted. In this case, both the decomposition of methane hydrate and the formation of carbon dioxide hydrate can occur. This problem is stated in a one-dimensional linear formulation for the case of negative temperatures and gaseous carbon dioxide, which means that methane, carbon dioxide, ice, methane, and carbon dioxide hydrates may be present in the reservoir. A mathematical model is built based on the following: the laws of conservation of masses of methane, carbon dioxide, and ice; Darcy’s law for the gas phase motion; equation of state of real gas; energy equation taking into account thermal conductivity, convection, adiabatic cooling, the Joule — Thomson effect, and the release or absorption of latent heat of hydrate formation. The modelling assumes that phase transitions occur in an equilibrium mode and that methane can be completely replaced by carbon dioxide. The results of numerical experiments are presented.


2008 ◽  
Vol 6 ◽  
pp. 205-209
Author(s):  
V.Sh. Shagapov ◽  
R.R. Urazov

The flow of wet natural gas in the pipeline is considered in the presence of the formation of gas hydrates on the internal walls of the channel. In the description of the phenomenon, such interrelated processes as phase transformations and mass transfer of water into the composition of gas hydrates, heat transfer between the gas stream and the environment, heat conductivity in the ground are taken into account.


Author(s):  
Angelina S. CHIGLINTSEVA ◽  
◽  
Azat A. NASYROV ◽  
Igor’ A. CHIGLINTSEV ◽  
Sergey A. LEPIKHIN ◽  
...  

The paper proposes a mathematical model describing the process of the hydrate formation in a vertical pipeline through which the gas is transported from the dome-separator designed to eliminate a technogenic spill of oil from the well at the seabed. If the dome is located in the zone of stable hydrate existence, then hydrate deposits can form within and in the pipeline, which can lead to the pipeline clogging. The influence of the presence of a pipeline insulation coating, which consists of the layers of polyurethane and polyurethane foam, and its thickness on the hydrate formation process in a steel pipeline is studied on the basis of numerical modeling. It is shown that if the gas is derived from the dome located at a depth of 1500 m, the zone of hydrate deposits is formed at the inlet of the pipeline without insulation (in the dome-separator vicinity). When the thermal insulation of the pipeline is used, it leads to an upward shift of the hydrate formation conditions. As a result, depending on the thickness of the insulation coating, the zone of hydrate deposits is formed near the outlet of the pipeline (in the ocean surface vicinity) or no hydrates are formed in the pipe. It is also shown that the motion of the seawater around the pipeline has almost no effect on the process of hydrate formation within the pipe.


2018 ◽  
Vol 7 (4.38) ◽  
pp. 1197
Author(s):  
Azat Askatovich Nasyrov ◽  
Igor Aleksandrovich Chiglintsev ◽  
Sergey Anatolievich Lepikhin ◽  
. .

The work presents a mathematical model for the hydrocarbon crude extraction from the bottomhole zone by a cylindrical dome-separator. The proposed model allows determining the thermobaric conditions and dynamics of the boundaries of stratified phases in the installation during its operation and analyzing the complications associated with the possibility of formation of gas hydrates.  


2010 ◽  
Vol 7 ◽  
pp. 90-97
Author(s):  
M.N. Galimzianov ◽  
I.A. Chiglintsev ◽  
U.O. Agisheva ◽  
V.A. Buzina

Formation of gas hydrates under shock wave impact on bubble media (two-dimensional case) The dynamics of plane one-dimensional shock waves applied to the available experimental data for the water–freon media is studied on the base of the theoretical model of the bubble liquid improved with taking into account possible hydrate formation. The scheme of accounting of the bubble crushing in a shock wave that is one of the main factors in the hydrate formation intensification with increasing shock wave amplitude is proposed.


2014 ◽  
Vol 14 (1) ◽  
pp. 45
Author(s):  
Peyman Sabzi ◽  
Saheb Noroozi

Gas hydrates formation is considered as one the greatest obstacles in gas transportation systems. Problems related to gas hydrate formation is more severe when dealing with transportation at low temperatures of deep water. In order to avoid formation of Gas hydrates, different inhibitors are used. Methanol is one of the most common and economically efficient inhibitor. Adding methanol to the flow lines, changes the thermodynamic equilibrium situation of the system. In order to predict these changes in thermodynamic behavior of the system, a series of modelings are performed using Matlab software in this paper. The main approach in this modeling is on the basis of Van der Waals and Plateau's thermodynamic approach. The obtained results of a system containing water, Methane and Methanol showed that hydrate formation pressure increases due to the increase of inhibitor amount in constant temperature and this increase is more in higher temperatures. Furthermore, these results were in harmony with the available empirical data.Keywords: Gas hydrates, thermodynamic inhibitor, modelling, pipeline blockage


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3615
Author(s):  
Florian Filarsky ◽  
Julian Wieser ◽  
Heyko Juergen Schultz

Gas hydrates show great potential with regard to various technical applications, such as gas conditioning, separation and storage. Hence, there has been an increased interest in applied gas hydrate research worldwide in recent years. This paper describes the development of an energetically promising, highly attractive rapid gas hydrate production process that enables the instantaneous conditioning and storage of gases in the form of solid hydrates, as an alternative to costly established processes, such as, for example, cryogenic demethanization. In the first step of the investigations, three different reactor concepts for rapid hydrate formation were evaluated. It could be shown that coupled spraying with stirring provided the fastest hydrate formation and highest gas uptakes in the hydrate phase. In the second step, extensive experimental series were executed, using various different gas compositions on the example of synthetic natural gas mixtures containing methane, ethane and propane. Methane is eliminated from the gas phase and stored in gas hydrates. The experiments were conducted under moderate conditions (8 bar(g), 9–14 °C), using tetrahydrofuran as a thermodynamic promoter in a stoichiometric concentration of 5.56 mole%. High storage capacities, formation rates and separation efficiencies were achieved at moderate operation conditions supported by rough economic considerations, successfully showing the feasibility of this innovative concept. An adapted McCabe-Thiele diagram was created to approximately determine the necessary theoretical separation stage numbers for high purity gas separation requirements.


2016 ◽  
Vol 470 (2) ◽  
pp. 1046-1049 ◽  
Author(s):  
G. I. Barenblatt ◽  
L. I. Lobkovsky ◽  
R. I. Nigmatulin

2021 ◽  
Vol 3 (144) ◽  
pp. 22-31
Author(s):  
Viktor S. Grigor’yev ◽  
◽  
Il’ya V. Romanov

The ability of gas hydrates to concentrate gas into a solid chelate structure and the properties of self-preservation of gas hydrates at negative temperatures allows us to consider the possibility of developing a method for the utilization of biogas, environmentally safe storage and transportation of biomethane. (Research purpose) The research purpose is in substantiation the technological possibilities of obtaining synthetic mixed gas hydrates of biogas components, their storage and transportation based on the analysis of the existing regularities of the formation of gas hydrates in time, temperature and external pressure. (Materials and methods) The article presents the accumulated results of studies of the process of obtaining artificial hydrates of natural gas and methane- containing gas mixtures at various initial static pressures and temperatures. The object of research to substantiate the parameters of artificial creation of gas hydrates is biogas obtained during anaerobic thermophilic fermentation of organic waste at an existing experimental biogas plant. Mixed feed SK-8 with a humidity of 90-92 percent was used as an organic substrate of constant composition. The composition of biogas was studied using the Optima-7 Biogas gas analyzer. (Results and discussion) The article presents a process model and a technical appearance of an installation for producing gas motor fuel from the biogas of anaerobic digestion of organic waste of the agro-industrial complex. The hydrate formation time depends on the increase in the interfacial surface and the movement of gas bubbles relative to the liquid, which can be regulated by acting on the hydrate formation zone (shock wave, electromagnetic, mechanical, chemical, temperature). (Conclusions) The research results can be used in modeling processes in two-phase media during the formation of gas hydrates and the creation of installations for their production.


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