scholarly journals Study on the decomposition mechanism and kinetic model of natural gas hydrate slurry in water-in-oil emulsion flowing systems

RSC Advances ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 3879-3889
Author(s):  
Xiaofang Lv ◽  
Yang Liu ◽  
Shidong Zhou ◽  
Bohui Shi ◽  
Kele Yan
Keyword(s):  
Kinetic Model ◽  
Natural Gas ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Decomposition Mechanism ◽  
Flow Assurance ◽  
Natural Gas Hydrate ◽  
Oil Emulsion ◽  
Natural Gas Hydrates ◽  
Water In Oil Emulsion

Hydrate slurry decomposition in flow systems is a significant subject that involves flow assurance and development of marine natural gas hydrates.

scholarly journals Study of the Comprehensive Kinetic Model of Natural Gas Hydrate Formation in a Water-in-Oil Emulsion Flow System

ACS Omega ◽  
2020 ◽  
Vol 5 (51) ◽  
pp. 33101-33112
Author(s):  
Xiaofang Lv ◽  
Yang Liu ◽  
Bohui Shi ◽  
Shidong Zhou ◽  
Yun Lei ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Natural Gas ◽  
Gas Hydrate ◽  
Flow System ◽  
Hydrate Formation ◽  
Natural Gas Hydrate ◽  
Oil Emulsion ◽  
Gas Hydrate Formation ◽  
Emulsion Flow ◽  
Water In Oil Emulsion

MRI Visualization of Spontaneous Methane Production From Hydrates in Sandstone Core Plugs When Exposed to CO2

SPE Journal ◽  
2008 ◽  
Vol 13 (02) ◽  
pp. 146-152 ◽  
Author(s):  
Arne Graue ◽  
B. Kvamme ◽  
Bernie Baldwin ◽  
Jim Stevens ◽  
James J. Howard ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Methane Production ◽  
Methane Hydrate ◽  
Co2 Storage ◽  
Natural Gas Hydrate ◽  
Hydrate Dissociation ◽  
Natural Gas Hydrates ◽  
The Stability

Summary Magnetic resonance imaging (MRI) of core samples in laboratory experiments showed that CO2 storage in gas hydrates formed in porous rock resulted in the spontaneous production of methane with no associated water production. The exposure of methane hydrate in the pores to liquid CO2 resulted in methane production from the hydrate that suggested the exchange of methane molecules with CO2 molecules within the hydrate without the addition or subtraction of significant amounts of heat. Thermodynamic simulations based on Phase Field Theory were in agreement with these results and predicted similar methane production rates that were observed in several experiments. MRI-based 3D visualizations of the formation of hydrates in the porous rock and the methane production improved the interpretation of the experiments. The sequestration of an important greenhouse gas while simultaneously producing the freed natural gas offers access to the significant amounts of energy bound in natural gas hydrates and also offers an attractive potential for CO2 storage. The potential danger associated with catastrophic dissociation of hydrate structures in nature and the corresponding collapse of geological formations is reduced because of the increased thermodynamic stability of the CO2 hydrate relative to the natural gas hydrate. Introduction The replacement of methane in natural gas hydrates with CO2 presents an attractive scenario of providing a source of abundant natural gas while establishing a thermodynamically more stable hydrate accumulation. Natural gas hydrates represent an enormous potential energy source as the total energy corresponding to natural gas entrapped in hydrate reservoirs is estimated to be more than twice the energy of all known energy sources of coal, oil, and gas (Sloan 2003). Thermodynamic stability of the hydrate is sensitive to local temperature and pressure, but all components in the hydrate have to be in equilibrium with the surroundings if the hydrate is to be thermodynamically stable. Natural gas hydrate accumulations are therefore rarely in a state of complete stability in a strict thermodynamic sense. Typically, the hydrate associated with fine-grain sediments is trapped between low-permeability layers that keep the system in a state of very slow dynamics. One concern of hydrate dissociation, especially near the surface of either submarine or permafrost-associated deposits, is the potential for the release of methane to the water column or atmosphere. Methane represents an environmental concern because it is a more aggressive (~25 times) greenhouse gas than CO2. A more serious concern is related to the stability of these hydrate formations and its impact on the surrounding sediments. Changes in local conditions of temperature, pressure, or surrounding fluids can change the dynamics of the system and lead to catastrophic dissociation of the hydrates and consequent sediment instability. The Storegga mudslide in offshore Norway was created by several catastrophic hydrate dissociations. The largest of these was estimated to have occurred 7,000 years ago and was believed to have created a massive tsunami (Dawson et al. 1988). The replacement of natural gas hydrate with CO2 hydrate has the potential to increase the stability of hydrate-saturated sediments under near-surface conditions. Hydrocarbon exploitation in hydrate-bearing regions has the additional challenge to drilling operations of controlling heat production from drilling and its potential risk of local hydrate dissociation (Yakushev and Collett 1992). The molar volume of hydrate is 25-30% greater than the volume of liquid water under the same temperature-pressure conditions. Any production scenario for natural gas hydrate that involves significant dissociation of the hydrate (e.g., pressure depletion) has to account for the release of significant amounts of water that in turn affects the local mechanical stress on the reservoir formation. In the worst case, this would lead to local collapse of the surrounding formation. Natural gas production by CO2 exchange and sequestration benefits from the observation that there is little or no associated liquid water production during this process. Production of gas by hydrate dissociation can produce large volumes of associated water, and can create a significant environmental problem that would severely limit the economic potential. The conversion from methane hydrate to a CO2 hydrate is thermodynamically favorable in terms of free energy differences, and the phase transition is coupled to corresponding processes of mass and heat transport. The essential question is then if it is possible to actually convert methane hydrate as found in sediments to CO2 hydrate. Experiments that formed natural gas hydrates in porous sandstone core plugs used MRI to monitor the dynamics of hydrate formation and reformation. The paper emphasizes the experimental procedures developed to form the initial natural gas hydrates in sandstone pores and the subsequent exchange with CO2 while monitoring the dynamic process with 3D imaging on a sub millimetre scale. The in-situ imaging illustrates the production of methane from methane hydrate when exposed to liquid CO2 without any external heating.

scholarly journals Investigation on the Secondary Generation of Natural Gas Hydrates in Horizontal Wellbore Caused by Pressure Jump during the Depressurization Development of Hydrate Bearing Layers

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Qingjun Du ◽  
Yongge Liu ◽  
Jian Hou ◽  
Lina Shi ◽  
Wenbin Wang ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Horizontal Well ◽  
Pressure Jump ◽  
Natural Gas Hydrate ◽  
Water Transportation ◽  
Natural Gas Hydrates ◽  
Environment Temperature ◽  
Wellbore Pressure

When the depressurization development of a hydrate-bearing layer is initiated, the temperature of the near-wellbore formation quickly decreases to near the equilibrium temperature due to the dissociation of natural gas hydrate Therefore, the secondary generation of natural gas hydrates in the wellbore easily occurs if pressure jumps to a high value due to the changes of production rates or shutdown of the well. Though hydrate generation in the process of high-pressure drilling and gas and water transportation has been widely investigated, the secondary generation of natural gas hydrates caused by pressure jump during the depressurization development process is not fully understood. In this study, the multiphase pipe flow of a horizontal well, the Vyniauskas–Bishnoi generation dynamics of natural gas hydrate, and a decomposition dynamics model developed by Kim and Bishnoi are combined to build a set of horizontal well gas–liquid–solid three-phase flow models, which consider the phase transition in the wellbore and distinguished the secondary hydrate generation area in the wellbore under different temperature and pressure conditions. The results show that when the toe-end pressure is 7 MPa and the environment temperature is 6.4°C, the secondary hydrate generation exists in the horizontal section of the horizontal well, and the maximum hydrate flow velocity in the wellbore is 0.044 m3/d. A high toe-end pressure, low environment temperature, and high gas output will result in a greater hydrate generation in the wellbore, and the wellbore pressure will have a remarkable influence on the amount generated and its range.

Natural gas hydrate formation dynamics in a diesel water-in-oil emulsion system

2018 ◽  
Vol 36 (20) ◽  
pp. 1649-1656 ◽  
Author(s):  
Zhen Pan ◽  
Zhe Wang ◽  
Zhien Zhang ◽  
Guiyang Ma ◽  
Li Zhang ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Emulsion System ◽  
Natural Gas Hydrate ◽  
Oil Emulsion ◽  
Gas Hydrate Formation ◽  
Formation Dynamics ◽  
Water In Oil Emulsion

scholarly journals Controlled Production of Natural Gas Hydrates in an Experimental Device with an Internal Circulation Circuit

2021 ◽  
Vol 12 (1) ◽  
pp. 312
Author(s):  
Dávid Hečko ◽  
Milan Malcho ◽  
Pavol Mičko ◽  
Nikola Čajová Kantová ◽  
Zuzana Kolková ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Energy Intensity ◽  
Hydrate Formation ◽  
Experimental Device ◽  
Natural Gas Hydrate ◽  
Hydrocarbon Gases ◽  
Natural Gas Hydrates ◽  
Circulation Circuit

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.

scholarly journals Analysis of Multi-Phase Mixed Slurry Horizontal Section Migration Efficiency in Natural Gas Hydrate Drilling and Production Method Based on Double-Layer Continuous Pipe and Double Gradient Drilling

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3792
Author(s):  
Yang Tang ◽  
Jiaxin Yao ◽  
Guorong Wang ◽  
Yin He ◽  
Peng Sun
Keyword(s):  
Solid State ◽  
Natural Gas ◽  
Double Layer ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Simulation Software ◽  
Natural Gas Hydrate ◽  
Horizontal Section ◽  
Natural Gas Hydrates ◽  
Drilling Method

In order to improve the recovery efficiency of natural gas hydrate in solid-state fluidized mining of natural gas hydrate, we solve drilling safety problems, such as narrow density of natural gas hydrate formation pressure window and poor wellbore stability caused by high upstream velocity during drilling and production. In this study—in order to increase the natural gas hydrate output and reduce production costs—based on the principle of the solid-state fluidized mining, a natural gas hydrate drilling method based on double-layer continuous-pipe double-gradient drilling was proposed to solve the above problems. The article introduces a drilling and production tool combination scheme and the mathematical model of wellbore-pressure dynamic regulation. Simulation software was used to study and compare the migration efficiency of multiphase mixed slurries of sediment and natural gas hydrates in the horizontal section of the double-layer continuous-pipe double-gradient drilling method and traditional drilling method. The results show that the transport efficiency of the multiphase mixed slurry of sediment and natural gas hydrate in the horizontal section of the double-layer continuous-pipe double-gradient drilling method is better than the traditional drilling method under the same conditions. When the double-layer continuous-pipe double-gradient drilling method is adopted, the multiphase mixed slurry of sediment and natural gas hydrate is transported in the pipe and has the function of the submarine lift pump, which effectively avoids the problem of the stability of the shaft wall caused by excessive flow velocity. This will also be more suitable for the transportation of large-diameter particles during the solid-state fluidized mining of natural gas hydrates.

Investigation on natural gas hydrate dissociation from a slurry to a water-in-oil emulsion in a high-pressure flow loop

Fuel ◽  
2018 ◽  
Vol 233 ◽  
pp. 743-758 ◽  
Author(s):  
Bo-Hui Shi ◽  
Shang-Fei Song ◽  
Xiao-Fang Lv ◽  
Wen-Qing Li ◽  
Ying Wang ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Gas Hydrate ◽  
Natural Gas Hydrate ◽  
Flow Loop ◽  
Hydrate Dissociation ◽  
Pressure Flow ◽  
Oil Emulsion ◽  
Water In Oil Emulsion

scholarly journals Effects of Combined Sorbitan Monolaurate Anti-Agglomerants on Viscosity of Water-in-Oil Emulsion and Natural Gas Hydrate Slurry

Energies ◽  
2017 ◽  
Vol 10 (8) ◽  
pp. 1105 ◽  
Author(s):  
Yining Lv ◽  
Yintang Guan ◽  
Shudi Guo ◽  
Qinglan Ma ◽  
Jing Gong ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Hydrate ◽  
Natural Gas Hydrate ◽  
Sorbitan Monolaurate ◽  
Oil Emulsion ◽  
Water In Oil Emulsion

Status of Natural Gas Hydrate Flow Assurance Research in China: A Review

2021 ◽  
Author(s):  
Bohui Shi ◽  
Shangfei Song ◽  
Yuchuan Chen ◽  
Xu Duan ◽  
Qingyun Liao ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Hydrate ◽  
Flow Assurance ◽  
Natural Gas Hydrate
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