Mechanism of Casing’s Shear Failure in Water Injection Oilfield and Its Numerical Simulation

Author(s):  
Xiaolan HUANG ◽  
Jianjun LIU
2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yijie Shi ◽  
Pengfei Wang ◽  
Ronghua Liu ◽  
Xuanhao Tan ◽  
Wen Zhang

Coalbed water injection is the most basic and effective dust-proof technology in the coal mining face. To understand the influence of coalbed water injection process parameters and coalbed characteristic parameters on coal wetting radius, this paper uses Fluent computational fluid dynamics software to systematically study the seepage process of coalbed water injection under different process parameters and coalbed characteristic parameters, calculation results of which are applied to engineering practice. The results show that the numerical simulation can help to predict the wetness range of coalbed water injection, and the results can provide guidance for the onsite design of coalbed water injection process parameters. The effect of dust reduction applied to onsite coalbed water injection is significant, with the average dust reduction rates during coal cutting and support moving being 67.85% and 46.07%, respectively, which effectively reduces the dust concentration on the working face and improves the working environment.


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.


2014 ◽  
Vol 941-944 ◽  
pp. 1817-1821
Author(s):  
Xiao Xiong Wang ◽  
Jing Liu ◽  
Jing Tao Han ◽  
Qian Liu

A numerical simulation was conducted to investigate the effect of the punching clearance, the thickness of sheet, and the hardness of polyurethane pad on the process of punching by finite element program ABAQUS which based on shear failure criterion and arbitrary Lagrangian-Eulerian adaptive meshing method. And the collapse height dimension and width dimension tendency of the sheet under different control parameters was analyzed after punching process according to this simulation result. The results show that the collapse height dimension and width dimension decreased with the increase of the polyurethane hardness, it means the cross section quality perspicuously has been increased; the collapse height dimension and width dimension decreased with the increasing of the sheet thickness; while the influence of the punching gap is indistinctive.


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


2014 ◽  
Vol 926-930 ◽  
pp. 593-596
Author(s):  
Fang Wang ◽  
Chong Shi ◽  
Kai Hua Chen ◽  
De Jie Li ◽  
Ke Han

The process of open-pit mining can lead to high slopes in iron mines, and natural slopes should be rebuilt by the method of roof fall as the exploitation style turns from open-pit mining to the underground mining. So the slope can be steep, deep and may has the characteristics of collapse. It is difficult to describe the stabilization of the mining slope by a conventional safety factor method. Through the numerical simulation of underground mining process, this paper analyzes the result of distortion stress and rock movement rupture range. Studies have shown that the failure mode is dominated by tensile failure as a pattern of collapse and few is dominated by shear failure. The failure zone is controlled by rock mass parameters and structures. The results can be helpful for the proposition of exploitation program and safety management design.


2013 ◽  
Vol 804 ◽  
pp. 292-297 ◽  
Author(s):  
Song Gao ◽  
Ya Bin Wang ◽  
Xiu Feng Li

Penetration is an important topic in the military and protection engineering field. Based on *MAT_PLASTIC_KINEMATIC of LS-DYNA program, this report studies effects of failure strain of the material parameters on structure of penetrating projectile. By establishing a group of numerical models about 45 steel hemispherical projectile penetrating semi-infinite concrete targets, this research aimed at analyzing effects of different failure strain values related to the destruction of the internal bracket structures of this projectile. At the same time, it studied the criterion of failure on finite dynamic program. The numerical results show that the use of failure strain in this model can well simulate damage of internal bracket structures of the projectile. Test was carried on based on this conclusion, which showed that bracket plate is subjected to shear failure in process of penetration, and numerical simulation was consistent with the experimental results.


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