Influence of the Particle Size of Porous Media on the Formation of Natural Gas Hydrate: A Review

The spiral separator is an important tool for desanding in natural gas hydrate production, and the change of hydrate reservoir parameters has a great impact on spiral separator behavior. Mastering the influence law is helpful to improve the separation performance. Until now, there was still no detailed analysis of the effect mechanism between reservoir parameters and spiral separator behavior. In this paper, a downhole spiral separator was designed. Then, the effects of reservoir parameters (particle size, hydrate, volume fraction, and sand volume fraction) on separation performance (discrete phase distribution, separation efficiency, and differential pressure) with different flow rates were investigated by numerical simulation method Fluent 18.0. The results show that effects degree of reservoir parameters is in order from large to small: sand phase volume fraction, particle size, hydrate volume fraction. As the particle size increases, the separation performance is improved. When the sand volume fraction increases, the natural gas hydrate (NGH) recovery efficiency and differential pressure both increase, but the sand removal efficiency decreases. When the hydrate fraction increases, the separation performance change law is opposite to that when the sand volume fraction increases. In addition, with increasing the flow rate, the efficiency and differential pressure increase. Therefore, reservoir saturation and porosity can balance NGH recovery efficiency and sand removal efficiency. Furthermore, the spiral separator has good performance under the change of reservoir parameters. The performance of the NGH spiral separator can be also maintained by increasing the flow rate.

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Micro-CT analysis of structural characteristics of natural gas hydrate in porous media during decomposition

Journal of Natural Gas Science and Engineering ◽

10.1016/j.jngse.2016.02.054 ◽

2016 ◽

Vol 31 ◽

pp. 139-148 ◽

Cited By ~ 25

Author(s):

Yangsheng Zhao ◽

Jianzhong Zhao ◽

Dinxian Shi ◽

Zengchao Feng ◽

Weiguo Liang ◽

...

Keyword(s):

Porous Media ◽

Natural Gas ◽

Gas Hydrate ◽

Structural Characteristics ◽

Micro Ct ◽

Natural Gas Hydrate ◽

Ct Analysis

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Natural gas storage and transportation within gas hydrate of smaller particle: Size dependence of self-preservation phenomenon of natural gas hydrate

Chemical Engineering Science ◽

10.1016/j.ces.2014.07.050 ◽

2014 ◽

Vol 118 ◽

pp. 208-213 ◽

Cited By ~ 76

Author(s):

Hiroko Mimachi ◽

Satoshi Takeya ◽

Akio Yoneyama ◽

Kazuyuki Hyodo ◽

Tohoru Takeda ◽

...

Keyword(s):

Particle Size ◽

Natural Gas ◽

Gas Hydrate ◽

Size Dependence ◽

Gas Storage ◽

Natural Gas Hydrate ◽

Natural Gas Storage

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Pore Structure Fractal Characterization and Permeability Simulation of Natural Gas Hydrate Reservoir Based on CT Images

Geofluids ◽

10.1155/2020/6934691 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Hang Bian ◽

Yuxuan Xia ◽

Cheng Lu ◽

Xuwen Qin ◽

Qingbang Meng ◽

...

Keyword(s):

Porous Media ◽

Fractal Dimension ◽

Natural Gas ◽

South China Sea ◽

Pore Structure ◽

South China ◽

Gas Hydrate ◽

Ct Scanning ◽

Natural Gas Hydrate ◽

Clayey Silt

The gas-water two-phase seepage process is complex during the depressurization process of natural gas hydrate in a clayey silt reservoir in the South China Sea, the transport mechanism of which has not been clarified as it is affected by the pore structure. In this study, we select six clayey silt samples formed after the dissociation of natural gas hydrate in the South China Sea, employing CT scanning technology to observe the pore structure of clayey silt porous media directly. The original CT scanning images are further processed to get the binarized images of the samples, which can be used for simulation of the porosity and absolute permeability. Based on the fractal geometry theory, pore structures of the samples are quantitatively characterized from the aspect of pore distribution, heterogeneity, and anisotropy (represented by three main fractal geometric parameters: fractal dimension, lacunarity, and succolarity, respectively). As a comparison, the binarized CT images of two conventional sandstone cores are simulated with the same parameters. The results show that the correlation between porosity and permeability of the hydrate samples is poor, while there is a strong correlation among the succolarity and the permeability. Fractal dimension (represents complexity) of clayey silt samples is higher compared with conventional sandstone cores. Lacunarity explains the difference in permeability among samples from the perspective of pore throat diameter and connectivity. Succolarity indicates the extent to which the fluid in the pore is permeable, which can be used to characterize the anisotropy of pore structures. Therefore, these three fractal parameters clarify the relationship between the microstructure and macroscopic physical properties of clayey silt porous media.

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Study on the Promotion of Natural Gas Hydrate Formation by SDBS in Porous Media

Journal of Oil and Gas Technology ◽

10.12677/jogt.2020.422056 ◽

2020 ◽

Vol 42 (02) ◽

pp. 350-360

Author(s):

超孙

Keyword(s):

Porous Media ◽

Natural Gas ◽

Gas Hydrate ◽

Hydrate Formation ◽

Natural Gas Hydrate ◽

Gas Hydrate Formation

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Simulation of the Decomposition of Natural Gas Hydrate in Porous Media by Hot Water Injection

Energy Exploration & Exploitation ◽

10.1260/014459808787548732 ◽

2008 ◽

Vol 26 (4) ◽

pp. 267-279 ◽

Cited By ~ 3

Author(s):

Xitang Zhou ◽

Xianhua Tao ◽

Deqing Liang ◽

Shuanshi Fan

Keyword(s):

Porous Media ◽

Natural Gas ◽

Gas Hydrate ◽

Water Injection ◽

Hot Water ◽

Natural Gas Hydrate

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Technical Analysis of Sand Production for Offshore Natural Gas Hydrate Trials in South China Sea

10.2118/206411-ms ◽

2021 ◽

Author(s):

Kun An ◽

Lawrence Khin Leong Lau ◽

Jian Li ◽

Jia Liu

Keyword(s):

Particle Size ◽

Natural Gas ◽

South China Sea ◽

South China ◽

Gas Hydrate ◽

Clean Energy ◽

Technical Analysis ◽

Sand Production ◽

Natural Gas Hydrate ◽

China Sea

Abstract Natural gas hydrate emerges as a sustainable and alternative clean energy source. Japan (2013) and China (2017) have performed production trials on marine natural gas hydrate successfully. Sand production with associated risk is one of the main challenges for offshore natural gas hydrate production trials in Japan and China. Technical assessment related to sand production, transport and erosion is a crucial part for overall sand management strategy. This paper demonstrates the importance of flow assurance for marine natural gas hydrate production through the analysis of sand management in South China Sea ShenHu area. Multiphase modelling tool is used to investigate sand transport phenomenon, with parametric study focuses on the effects of production rates, particle bed height and sand particle size. Detailed analysis of particle flow and related erosion along production flow path is investigated by developing a 3-dimensional Computational Fluids Dynamics (CFD) model. Based on the matrix of sensitivity study, steady state operational map for continuous marine natural gas hydrate production is proposed. Such operational map provides useful risks level ranking based on actual field parameters including gas production rate, sand loading and particle size. The operator can maintain production at a lower risk based on the operational map. Through detailed technical analysis of sand production and transport, risks associated with sand blockage and erosion can be actively managed. This provides high values in terms of operational safety, asset integrity, and full compliance with related national or international HSSE standards.

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