scholarly journals Study on the gas migration laws of non-pillar mining with gob-side entry retaining in high gas outburst coal seam

2021 ◽  
Vol 861 (5) ◽  
pp. 052058
Author(s):  
Jun Yang ◽  
Bowen Qiao ◽  
Yubing Gao ◽  
Hainan Gao ◽  
Xingjian Wei ◽  
...  
Keyword(s):  
Coal Seam ◽  
Gas Migration ◽  
Gas Outburst ◽  
Pillar Mining ◽  
Outburst Coal Seam

scholarly journals The Migration of Coalbed Methane under Mining Pressure and Air Injection: A Case Study in China

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Liqiang Zhang ◽  
Yu Wu ◽  
Hai Pu ◽  
Xiaoping He ◽  
Pan Li
Keyword(s):  
Coal Seam ◽  
Coalbed Methane ◽  
High Efficiency ◽  
Air Injection ◽  
Gas Migration ◽  
Gas Outburst ◽  
Working Face ◽  
The Matrix ◽  
Mining Pressure ◽  
And Migration

Gas outburst has always affected the safety of coal mining. To eliminate this risk by high-efficiency extraction of coalbed methane (CBM) in 4102 working face of number 3 coal seam in Hebi Number 3 coal mine, a model of CBM extraction in working face was established which was considering the mining impact of adjacent 4101 working face. In this model, the coupling relationships between stress, desorption, and migration of methane were analyzed. Moreover, we also studied the changes of methane pressure, plastic failure scope, and permeability of coal during the mining and then verified the results with the field data. And on this basis, a stimulation solution for methane extraction by injecting air into coal seam was presented, and the extraction effect was simulated. The simulation results show that the injection of air decreases the effective stress of coal which increases the permeability of coal and promotes the methane migration within the coal seam fractures. Besides, affected by the velocity of gas migration, the pressure drop between fractures and matrix will reduce with time while air injection can provide extra power for gas migration in fractures which causes the desorption and diffusion of methane in the matrix. So this stimulation solution can enhance the efficiency of gas extraction of coal seam and prevent gas outburst of the working face.

Research on Gas Outburst Coal Seam Mining Technology Based on the Theory of Gob-Side Entry Retaining

2019 ◽  
Vol 38 (2) ◽  
pp. 2377-2390
Author(s):  
Yongkui Shi ◽  
Xin Wang ◽  
Jian Hao ◽  
Jiahui Lin ◽  
Weijia Cheng ◽  
...  
Keyword(s):  
Coal Seam ◽  
Mining Technology ◽  
Gas Outburst ◽  
Outburst Coal Seam ◽  
Seam Mining

Coal and gas outburst mechanism of the “Three Soft” coal seam in western Henan

2010 ◽  
Vol 20 (5) ◽  
pp. 712-717 ◽  
Author(s):  
Dongji LEI ◽  
Chengwu LI ◽  
Zimin ZHANG ◽  
Yugui ZHANG
Keyword(s):  
Coal Seam ◽  
Coal And Gas Outburst ◽  
Gas Outburst ◽  
Soft Coal ◽  
Soft Coal Seam

Deformation Degree Estimate for Coal Seam using Well Logs as Input: A Case Study

2018 ◽  
Vol 23 (1) ◽  
pp. 89-101
Author(s):  
Tongjun Chen ◽  
Guodong Ma ◽  
Xin Wang ◽  
Ruofei Cui
Keyword(s):  
Cluster Analysis ◽  
Wavelet Analysis ◽  
Coal Seam ◽  
Large Scale ◽  
Coal And Gas Outburst ◽  
Well Logs ◽  
Deformation Degree ◽  
Ternary Diagrams ◽  
Medium Scale ◽  
Gas Outburst

The presence of tectonic deformed coal (TDC) is a prerequisite for coal-and-gas outburst. With a higher degree of TDC deformation, there is a greater possibility of coal-and-gas outbursts. The estimate of deformation degree for coal seam is critically important for mining safety. In this study, we focus on the No. 8 coal seam of Luling coalmine to identify and estimate its deformation degree using well logs, multiscale wavelet analysis, cluster analysis, and ternary diagrams. Since the original well logs contain noise, we first perform denoising with multi-scale wavelet analysis and produce their large-scale and medium-scale output components. Then, we classify the No. 8 coal seam into different sub lithological seams with cluster analysis using the large-scale and medium-scale components as inputs. The classified sub lithological seams include the undeformed coal, the cataclastic coal, the granulated coal, the mylonitized coal, and the gangue. Finally, we group the study area into four regions based on degree of deformation with ternary diagrams using classified sub seam thickness as input. The regions with III and IV deformation degrees are mostly composed of highly deformed TDCs and are prone to coal-and-gas outburst. [Figure: see text]

Determination of indices and critical values of gas parameters of the first gas outburst in a coal seam of the Xieqiao Mine

2012 ◽  
Vol 22 (1) ◽  
pp. 89-93 ◽  
Author(s):  
Ou Jianchun ◽  
Liu Mingju ◽  
Zhang Chunru ◽  
Liu Yanwei ◽  
Wei Jianping
Keyword(s):  
Coal Seam ◽  
Critical Values ◽  
Gas Outburst

Experimental Study on Deep Borehole Pre-Cracking Blasting of Drilling through Strata at Low Permeability Seam

2013 ◽  
Vol 868 ◽  
pp. 339-342
Author(s):  
Jian Liu ◽  
Qian Le
Keyword(s):  
Coal Seam ◽  
Control Area ◽  
Low Permeability ◽  
Gas Extraction ◽  
Test Results ◽  
Deep Borehole ◽  
Coal Seam Gas ◽  
Gas Concentration ◽  
Working Face ◽  
Outburst Coal Seam

In the process of roadway excavation in the low permeability outburst coal seam, with drilling through strata in the bottom drainage roadway extracting coal seam gas of control area. In order to improve extraction effect, the method that deep borehole pre-cracking blasting is used to increase the permeability of coal in the drilling through strata seam segment is proposed. The calculation formula on crushing circle and crack circle radius of deep borehole pre-cracking blasting are derived, and the effective loosening radius of blasting is calculated in theory, the research achievements are applied to field test, the test results show that deep borehole pre-cracking blasting permeability improvement technology is carried out in the drilling through strata of the low permeability outburst coal seam, the permeability of coal seam is improved by 180 times, the gas extraction scalar is raised by 8-10 tomes, during the process of roadway excavation, gas concentration of the working face is 0.2%-0.3%, and tunneling footage is increased by 2 times.

Study on Methods of Exploring the Loosening Radius of Deep-Hole Controlling Blasting

2013 ◽  
Vol 734-737 ◽  
pp. 650-655
Author(s):  
Wen Qing Zhang ◽  
Jian Liu
Keyword(s):  
Theoretical Analysis ◽  
Coal Seam ◽  
Gas Flow ◽  
Critical Factor ◽  
Field Investigation ◽  
Flow Index ◽  
Low Permeability ◽  
Deep Hole ◽  
Deep Borehole ◽  
Outburst Coal Seam

Deep borehole controlling blasting is one of the most popular methods which used to improve permeability of low permeability and highly gassy coal seam. Proper interval between blasting hole is the critical factor. On this paper, the theory and insufficiency of each method are discussed by theoretical analysis and field investigation. The result shows that, because of the complexity of outburst coal seam, the measuring result got by different methods is relative and declinational. We need to make a right choice according to the actual demand. And the method of gas flow index is quickly, visual and reliable, which to be worth paying the utmost attention to.

Reasons and Control Countermeasures of Special Soft Coal Roadway Deformation in Liangbei Coal Mine

2013 ◽  
Vol 671-674 ◽  
pp. 1144-1149
Author(s):  
Le Tuan Cheng ◽  
Jia Lin Zhang ◽  
Zheng Sheng Zou ◽  
Qing Bo Li
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Mining Area ◽  
Gas Content ◽  
Deformation And Failure ◽  
Gas Outburst ◽  
Soft Coal ◽  
Coal Roadway ◽  
Roadway Stability ◽  
Roadway Deformation

B1 coal seam located at -550m level in Liangbei Coal Mine is a typical "three-soft" seam. The coal roadway with a depth of 610-750m lies under the critical softening depth of the roadway, and its support difficulty coefficient is 1.5-2.0. The coal has poor air permeability, high gas content and high gas pressure, so danger degree of the gas outburst is relatively strong. The coal seam was destroyed in a disastrous state by more than 100 boreholes for gas outburst prevention during the excavation. This results in the difficulty in the roadway support. Engineering geological characteristics of the coal roadway at 11 mining area are introduced. Based on the engineering geo-mechanics method, the reasons of deformation and failure of the coal roadway are analyzed. In view of problems in excavation and support, as well as the type of the coal roadway deformation mechanism, the borehole parameters are optimized for the gas outburst prevention, and bolt-net-cable coupling support with high convex steel-belt is used to control the coal roadway stability at 11 mining area. Practice shows that the effect is fine.

Transformation of the Triaxial Seepage Device for Measuring Deformation of Coal Containing Gas

2013 ◽  
Vol 477-478 ◽  
pp. 610-613
Author(s):  
Mei Yuan ◽  
Qing Hao Meng ◽  
Jiang Xu ◽  
Bo Bo Li ◽  
Yu Qin Du
Keyword(s):  
Coal Seam ◽  
Gas Migration ◽  
Coal Deformation ◽  
Gas Seepage

To explore the regularity of deformation and gas migration of coal seam, the author transmits signal of strain foil on coal samples in all directions by transforming oil plug, oil plug seal, heat shrink tubing and wire seal, based on the existing triaxial seepage device. We can complete coal deformation and gas seepage test with this device under different temperature, different stress, different gas stress and so on.

Sign in / Sign up

Export Citation Format

Share Document