scholarly journals Numerical simulation research on failure law of surrounding rock in coalbed methane well

2018 ◽  
Vol 199 ◽  
pp. 022038
Author(s):  
Chao Liu ◽  
Mingyang Yang ◽  
Guofeng Yu ◽  
Changrui Duan
Keyword(s):  
Numerical Simulation ◽  
Coalbed Methane ◽  
Surrounding Rock ◽  
Simulation Research

Characteristic Law of Borehole Deformation Induced by the Temperature Change in the Surrounding Rock of Deep Coalbed Methane Well

2021 ◽  
pp. 1-18
Author(s):  
Xin Li ◽  
Jie Zhang ◽  
Cuinan Li ◽  
Weilin Chen ◽  
Jingbin He ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Coalbed Methane ◽  
Linear Equations ◽  
Surrounding Rock ◽  
Experimental Temperature ◽  
Borehole Stability ◽  
Fracture Angle ◽  
High Deformation ◽  
Rock Temperature ◽  
Primary Fracture

Abstract The borehole stability of the coalbed methane (CBM) well has always been vital in deep CBM exploration and development. The borehole instability of the deep CBM well is due to many complicated reasons. The change in the surrounding rock temperature is an important and easily overlooked factor among many reasons. In this research, we used methods that include experiment and numerical simulation to study the characteristic law of the borehole deformation induced by the changes in the surrounding rock temperature of deep CBM well. The experimental results of the stress–strain curves of five sets of experiments show that when the experimental temperature rises from 40 °C to 100 °C, the average stress when coal samples are broken gradually decreases from 81.09 MPa to 72.71 MPa. The proportion of plastic deformation in the entire deformation stage gradually increases from 7.8% to 25.7%. Moreover, the characteristics that some key mechanical parameters of coal samples change with the experimental temperature are fitted, and results show that as the experimental temperature rises from 40 °C to 100 °C, the compressive strength, elastic modulus, and main crack length of coal samples show a gradually decreasing trend. By contrast, the Pois-son's ratio and primary fracture angle show a gradually increasing trend. Moreover, the relativity of the linear equations obtained by fitting is all close to 1, which can accurately reflect the corresponding change trend. Numerical simulation results show that a high temperature of the surrounding rock of the deep CBM well results in a high range of stress concentration on the coal seam borehole and high deformation.

scholarly journals Numerical Simulation Research on Multi-field Coupling of Underground Energy Pile

2021 ◽  
Vol 1838 (1) ◽  
pp. 012061
Author(s):  
Qihui Zhou ◽  
Zhanjun Huang ◽  
Yong Wu ◽  
Huipeng Zhang ◽  
Yufeng Shi ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Simulation Research ◽  
Energy Pile ◽  
Field Coupling

Reasonable Entry Layout of Lower Seam in Multi-Seam Mining Based on Numerical Simulation

2013 ◽  
Vol 295-298 ◽  
pp. 2980-2984
Author(s):  
Xiang Qian Wang ◽  
Da Fa Yin ◽  
Zhao Ning Gao ◽  
Qi Feng Zhao
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Coal Seam ◽  
Coal Mine ◽  
Abutment Pressure ◽  
Surrounding Rock ◽  
Geological Conditions ◽  
Seam Mining

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.

Numerical Simulation of Blasting-Induced Damage in Grouting Curtain of Sandstone Aquifer for Vertical Shaft

2015 ◽  
Vol 723 ◽  
pp. 271-278
Author(s):  
Yu Liang Zhou ◽  
Dong Feng Yuan ◽  
Jun Zheng ◽  
Hua Wang
Keyword(s):  
Numerical Simulation ◽  
Prevention And Control ◽  
Damage Zone ◽  
Surrounding Rock ◽  
Damage Effect ◽  
Vertical Shaft ◽  
Control Methods ◽  
Sandstone Aquifer ◽  
And Control ◽  
Dynamic Damage

To provide a theoretical basis for water prevention and control methods and reasonable supporting techniques for vertical shaft, and to ensure the shaft construction to pass the sandstone aquifer safely and rapidly, numerical simulation using dynamic damage constitutive model, which was a user-defined constitutive modules in FLAC3D, a lagrangian analysis code in three dimensions, has been applied to investigate the dynamic damage effect in the surrounding rock of the grouting curtain near the driving working face for vertical shaft excavated by blasting. The results indicate that the distribution of the damage zone in the surrounding rock of the shaft, which decreases the effective thickness of the grouting curtain, was like a ellip-se, and that the depth of the damage zone in the surrounding rock of the shaft grouting curtain is fewer than that of the driving face floor. It can be concluded that the centre part of the driving face floor, especially the cutting hole zones, and the shaft wall in the greater horizontal stress side are the " key parts " for shaft water prevention and control methods.

Numerical Simulation on the Effect of Compound Roof Separation Position on Bolting Performance

2014 ◽  
Vol 953-954 ◽  
pp. 1638-1642
Author(s):  
Ai Qing Liu ◽  
Jian Zhang ◽  
Peng Cheng ◽  
Yu Hai Zhang
Keyword(s):  
Numerical Simulation ◽  
Simulation Analysis ◽  
Surrounding Rock ◽  
Cohesive Force ◽  
Roof Strata ◽  
Poor Stability ◽  
Key Parameter

Prestress is a key parameter in bolting, while the cohesive force of layers in the compound roof strata is low and prone to separation, causing the prestress proliferation very poor. With the method of numerical simulation analysis,the location of separation in compound roof to affect the performance of bolting support was researched. It is concluded the roof separation in the edge of anchorage zone, the prestress field superpose, but is away from the deep surrounding rock and shows poor stability,however the role of cable can make up for the defect of rockbolts support. It has been found the highly prestressed strength bolting system adapts to the compound roof.

Application of ABAQUS in Surrounding Rock Stability Analysis of Shallow Large Cross-Section Tunnel

2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Strong Support ◽  
Surrounding Rock ◽  
Tunnel Engineering ◽  
Tunnel Excavation ◽  
Rock Stability ◽  
Rock Bolting ◽  
Excavation Support ◽  
The Stability

HuJiaDi tunnel construction of Dai Gong highway is troublesome, the surrounding-rock mass give priority to full to strong weathering basalt, surrounding rock integrity is poor, weak self-stability of surrounding rock, and tunnel is prone to collapse. In order to reduce disturbance, taking advantage of the ability of rock mass, excavation adopt the method of "more steps, short footage and strong support". The excavation method using three steps excavation, The excavation footage is about 1.2 ~ 1.5 m; The surrounding rock bolting system still produce a large deformation after completion of the first support construction, it shows that the adopted support intensity cannot guarantee the stability of the tunnel engineering. Using ABAQUS to simulate tunnel excavation support, optimizing the support parameters of the tunnel, conducting comparative analysis with Monitoring and Measuring and numerical simulation results, it shows that the displacement - time curves have a certain consistency in numerical simulation of ABAQUS and Monitoring and Measuring.

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