Numerical Simulation of Compressive Experiment of Coal Seam in Deep Underground for Geological Storage of Carbon Dioxide

2013 ◽  
Vol 387 ◽  
pp. 189-192
Author(s):  
Feng Shan Han ◽  
Xin Li Wu

The geological storage of has been recognized as an important strategy to reduce emission in the atmosphere. Coal seam has strong absorption capacity for , hence the coal seam can be used as geological storage reservoirs, simple and easy to use modeling tools would be valuable in assessing the performance of deep underground geological storage. In this paper failure process of coal seam in deep underground under triaxial compressive experiment is presented by numerical simulation. That is of significance and valuable to those subjects of investigation of strength of coal seam in deep underground and mechanism of propagation and coalescence and evolvement of crack for coal seam in deep underground, it is shown by numerical simulation that failure shape of coal seam in deep underground under triaxial compressive experiment of lateral pressure of 25Mpa is typically shear failure, and characteristic of deformation is obviously elastic-brittle, which is significance to understand the performance of the coal seam in deep underground

2013 ◽  
Vol 868 ◽  
pp. 261-264
Author(s):  
Feng Shan Han ◽  
Xin Li Wu

The emission in atmosphere results in global climates warm, reduction of emission is growing concern of many countries. The geological storage of is effective method to reduce emission. Because coal seam has strong absorption capacity for ,the coal seam can be used as geological storage reservoirs, and coal seam has such characteristics that coal seam is preference for absorption and postponement for absorption, injection into coal seam can enhanced coal bed methane recovery, -ECBM, because and compete and absorb in coal seam , displace , hence coal bed methane can be obtained by The geological storage of in coal seam,is a energy generated by methane from injection into coal seam, injection into coal seam can not only reduce emission and but also enhance coal bed methane recovery, that is important to environment protection and energy sustainable development.


2019 ◽  
Vol 2019 ◽  
pp. 1-21
Author(s):  
Jun Xie ◽  
Yougang Yang

In order to analyze the torsional shear process of asphalt mixtures in a microscopic view, the numerical simulation of a torsional shear test of an asphalt mixture was carried out by discrete element method. Based on the defects of existing algorithms, the method of random reconstruction of the existing 3D model of the asphalt mixture was improved, and a new reconstruction method was proposed. A 3D numerical model of the asphalt mixture contained irregular-shaped coarse aggregate, mineral gradation, and asphalt mortar; furthermore, the particle algorithm established the air void distribution. Then, the numerical simulation of the asphalt mixture’s torsional shear was completed; in addition, the stress, displacement, and contact of the specimens at each stage were analyzed. The results showed that the stress and displacement in different stages changed greatly with the loading, i.e., the crack generated from a weak point on the surface and then spread to the ends with an oblique angle of about 45°. At the same time, the shear failure process of the asphalt mixture was studied. The virtual test method could accomplish the implementation of the numerical simulation of torsional shear; it also provided a good research method for analysis of the asphalt mixture’s shear failure process.


2011 ◽  
Vol 243-249 ◽  
pp. 3147-3150
Author(s):  
Shu Xian Liu ◽  
Xiao Gang Wei ◽  
Shu Hui Liu ◽  
Li Ping Lv

Disaster caused by exploiting underground coal is due to original mechanical equilibrium of underground rock has been destroyed when underground coal is exploited. And Stress redistribution and stress concentration of wall rock in the goaf happened too. As many complex factors exist such as complex structures of ground, multivariate stope boundary conditions, many stochastic mining factors and so on, it is difficult to evaluate the damage of the geological environment caused the excavation by surrounding underground coal accurately. Besides that, the coexistence of continuous and discontinuous of deformation and failure of wall rock make a strong impact on the ground, and the co-exist of tension, compression and shear failure also pay a great deal contribution to the destroy. Due to the mechanical property and deformation mechanism of goaf are complex , changeable, nonlinear and probabilistic, which changes with in space and time dynamically, it can not be studied analytically by the classical mathematical model and the theory of mechanics computation. Through finite element analysis software ABAQUS, a numerical simulation of the process of underground coal mining have been made. After make a research of the simulation process, it shows the change process of stress environment of wall rock and deformation and failure process of rock mass during the process of coal mining. The numerical simulation of the process can provide theoretical basis and technical support to the protection and reinforcement of laneway the process of coal excavation. Besides that, it also provides a scientific basis and has a great significance to reasonable Excavation and control of mind-out area.


2012 ◽  
Vol 616-618 ◽  
pp. 1591-1594
Author(s):  
Feng Shan Han ◽  
Li Song

The reduction of greenhouse gases emission is a growing concern of many countries. The geological storage of is useful and effective approaches to reduce emission. The oil and natural gas industries have long commercial practice of gas injection, enhanced oil recovery ( -EOR). Because coal seam has strong absorption capacity for ,the coal seam can be used as geological storage reservoirs, and coal seam has such characteristics that coal seam is preference for absorption and postponement for absorption, injection into coal seam can enhanced coal bed methane recovery, -ECBM, is a new energy generated by methane from injection into coal seam, and is beneficial complement of the energy , injection into coal seam can not only reduce greenhouse gases emission and but also enhance coal bed methane recovery, which is very significance to environment protection and energy sustainable development in china.


2011 ◽  
Vol 105-107 ◽  
pp. 1517-1520
Author(s):  
Yong Jun Zhang ◽  
Nian Jie Ma ◽  
Zi Min Zhang ◽  
Tian Rang Jia

With the full consideration of the heterogeneity, existing joints, and cracks in the rock, the coupled gas-rock model for investigating the failure process of coal-rock is established by introducing the related equations governing the evolution of stress, damage and gas permeability along with the deformation of coal and rock. A numerical approach of realistic failure process analysis (RFPA) to simulate the stratum movement, layer separation, the whole collapse progresses, and gas permeability changing of the protected coal seam is proposed. The numerical simulation results well displayed the whole processes of the cracks growth of gas seepage passage and the change of gas permeability for the closed distance protected coal seam. It can be seen from the distribution of acoustic emission in the space that the stratum failure is transferred from deeper to surface. By the analysis of the stress fields changing, the reasons of the gas permeability improvement of the protected coal seam are presented.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Teng Teng ◽  
Yuming Wang ◽  
Xiaoyan Zhu ◽  
Xiangyang Zhang ◽  
Sihai Yi ◽  
...  

Nuclear power has contributed humanity a lot since its successful usage in electricity power generation. According to the global statistics, nuclear power accounts for 16% of the total electricity generation in 2020. However, the rapid development of nuclear power also brings up some problems, in which the storage of nuclear waste is the thorny one. This work carries out a series of modeling and simulation analysis on the geological storage of nuclear waste in a gas-saturated deep coal seam. As the first step, a coupled heat-solid-gas model with three constitutional fields of heat transfer, coal deformation, and gas seepage that based on three governing conservation equations is proposed. The approved mechanical model covers series of interactive influences among temperature change, dual permeability of coal, thermal stress, and gas sorption. As the second step, a finite element numerical model and numerical simulation are developed to analyze the storage of nuclear waste in a gas-saturated deep coal seam based on the partial differential equations (PDE) solver of COMSOL Multiphysics with MATLAB. The numerical simulation is implemented and solved then to draw the following conclusions as the nuclear waste chamber heats up the surrounding coal seam firstly in the initial storage stage of 400 years and then be heated by the far-field reservoir. The initial velocity of gas flow decreases gradually with the increment of distance from the storage chamber. Coal gas flows outward from the central storage chamber to the outer area in the first 100 years when the gas pressure in the region nearby the central storage chamber is higher than that in the far region and flows back then while the temperature in the outer region is higher. The modeling and simulation studies are expected to provide a deep understanding on the geological storage of nuclear waste.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhichao Tian ◽  
Chunan Tang ◽  
Hao Li ◽  
Hui Xing ◽  
Xiangda Ning

Rock engineering occupies an important position in the 21st century. In the face of rock engineering disasters, we are only looking for the essential problems through experiments on rocks, but rock experiments cannot be realized in large numbers, so the article uses numerical simulation software RFPA (Realistic Failure Process Analysis) 2D Basic to simulate rock under different size conditions numerically. In this paper, a rock model with a diameter of 50 mm is used for simulation research. Meanwhile, five calculation models of height-to-diameter ratios of 1.0, 1.5, 2.0, 2.5, and 3 are used. Through simulation calculation, we find that the rock model failure is more than complicated when the value of the height-to-diameter ratio is exceedingly low (1), but as the height-to-diameter ratio increases, the failure mode will become simpler. The stress-concentrated failure will be in the form of axial failure. When the height-to-diameter ratio increases (1.5–2), other damage cracks appear on the basis of axial cleavage failure. As the height-to-diameter ratio continues to increase (about 2.5), only shear failure occurs. When the height-to-diameter ratio reaches a relatively high level (3), there will be both axial rip and other damage. When the height-to-diameter ratio is oversize, there will be both axial rip failure and end damage.


2013 ◽  
Vol 295-298 ◽  
pp. 2980-2984
Author(s):  
Xiang Qian Wang ◽  
Da Fa Yin ◽  
Zhao Ning Gao ◽  
Qi Feng Zhao

Based on the geological conditions of 6# coal seam and 8# coal seam in Xieqiao Coal Mine, to determine reasonable entry layout of lower seam in multi-seam mining, alternate internal entry layout, alternate exterior entry layout and overlapping entry layout were put forward and simulated by FLAC3D. Then stress distribution and displacement characteristics of surrounding rock were analyzed in the three ways of entry layout, leading to the conclusion that alternate internal entry layout is a better choice for multi-seam mining, for which makes the entry located in stress reduce zone and reduces the influence of abutment pressure of upper coal seam mining to a certain extent,. And the mining practice of Xieqiao Coal Mine tested the results, which will offer a beneficial reference for entry layout with similar geological conditions in multi-seam mining.


2005 ◽  
Vol 83 (31-32) ◽  
pp. 2609-2631 ◽  
Author(s):  
X.S. Tang ◽  
J.R. Zhang ◽  
C.X. Li ◽  
F.H. Xu ◽  
J. Pan

2011 ◽  
Vol 378-379 ◽  
pp. 15-18
Author(s):  
Yong Bin Zhang ◽  
Zheng Zhao Liang ◽  
Shi Bin Tang ◽  
Jing Hui Jia

In this paper, a ring shaped numerical specimen is used to studying the failure process in brittle materials. The ring specimen is subjected to a compressive diametral load and contains two angled central cracks. Numerical modeling in this study is performed. It is shown that the obtained numerical results are in a very good agreement with the experiments. Effect of the crack orientation angle on the failure modes and loading-displace responses is discussed. In the range of 0°~40°, the fracture paths are curvilinear forms starting from the tip of pre-existing cracks and grow towards the loading points. For the crack orientation angle 90°, vertical fractures will split the specimen and the horizontal cracks do not influence the fracture process.


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