scholarly journals The Relationship between Mining-Induced Stress and Coal Gas under an Optimized Support Scheme: A Case Study in the Guanyinshan Coal Mine, China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Tianjun Zhang ◽  
Jiaokun Wu ◽  
Yong Chen ◽  
Hong Ding ◽  
Hongyu Ma ◽  
...  
Keyword(s):  
Gas Pressure ◽  
Gas Content ◽  
Rock Support ◽  
Drill Cuttings ◽  
Coal Gas ◽  
Gas Desorption ◽  
Induced Stress ◽  
Coal And Gas Outbursts ◽  
Residual Gas ◽  
The Relationship

Stress is one of the main factors influencing coal and gas outbursts. The apparent effects of the crustal stress, the structural stress, and the mining-induced stress increase as the depth of mining increases. At present, there have been few studies of the relationship between the comprehensive analyses of the crustal stress, mining-induced stress, and coal gas. The in situ measurement of the relationship between stress-related behaviors and coal gas under the influence of mining was conducted through experimental analysis of surrounding rock support and coal and gas outburst control and optimization of surrounding rock support materials and system construction. The results showed that the mining-induced stress first increased to a peak value, then gradually decreased, and tended to stabilize as the footage progresses. Stress appears at 96 m ahead due to mining; after 57 m of advancing, there is a large increase until it passes through this area. The stress in front of the working face increases linearly, and the increase range is obviously larger than that of the coal body in a certain range on both sides. The support anchoring force gradually decreased and tended to be stable after rapidly increasing to a maximum value. The deep displacement of the roof increased linearly and tended to be stable after reaching an accumulated displacement which can reach 16-28 mm. The residual gas pressure in front of mining operations decreased rapidly, and beyond 15 m on each side of the roadway, it decreased significantly. The residual gas pressure and gas content were consistent with the gas desorption index of drill cuttings due to the influences of gas predrainage and mining. The stress along the direction of the roadway and the residual gas content, the residual gas pressure, and the gas desorption index of drill cuttings conform to the logarithmic functional relationship. The research results provide a basis for the comprehensive prevention and control of coal and gas outbursts from multiple angles considering stress, coal, and gas.

Gas Desorption of Different Particle Size Coal under the Effect of Electromagnetic Radiation

2014 ◽  
Vol 953-954 ◽  
pp. 1205-1209
Author(s):  
De Zhu Cheng ◽  
Ai Ling Du ◽  
Shan Chao Jiang ◽  
Ai Qin Du
Keyword(s):  
Particle Size ◽  
Optical Fiber ◽  
Electromagnetic Radiation ◽  
Coal Particle ◽  
Optical Fiber Sensor ◽  
Gas Content ◽  
Fiber Sensor ◽  
Particle Sizes ◽  
Coal Gas ◽  
Gas Desorption

Many factors can influence coal gas desorption. In this paper, the impact of coal particle size on coal gas desorption under the effect of microwave radiation was mainly studied. Infrared (IR) spectroscopy and optical fiber sensor were used to on-line detect and the qualitative and quantitative analysis of the desorbed gas. The analysis results of the infrared spectrogram showed that under the effect of electromagnetic radiation (2450Hz, 1.5μT), different particle sizes of coal sample could desorb gas which contained carbon dioxide, carbon monoxide and methane. The comparison of gas content detected by optical fiber sensor indicated that coal particle sizes had a significant influence on coal gas desorption. When coal particle was between 100 and 200 meshes, the gas content reached up to 27.58 m3/t.

Experimental Study on Gas Pressure Effects on Gas Desorption Characteristic of Coal Seam

2013 ◽  
Vol 318 ◽  
pp. 367-370 ◽  
Author(s):  
Lin Chao Dai ◽  
Da Yong Lu ◽  
Zhen Liu
Keyword(s):  
Coal Seam ◽  
Gas Adsorption ◽  
Experimental System ◽  
Gas Pressure ◽  
Pressure Effects ◽  
Gas Content ◽  
Equilibrium Pressure ◽  
Gas Desorption ◽  
Exploitation And Utilization ◽  
The Impact

To further explore the impact of gas pressure on gas desorption and flowing law, the gas desorption experimental system designed autonomously is used to carry out studies on gas desorption experiment under different gas pressures. By data fitting, the relationship between gas desorption quantity and time is obtained and also established the model for gas desorption. The results show that: the gas desorption quantity curves is "The first half rises sharply, the latter half segment is gently rising and eventually becomes stabilized", and when the gas adsorption equilibrium pressure is the greater, the gas desorption amount is greater. And the formula can describe the gas desorption law well, the correlation coefficient R2 is above 0.97. The study provides an important theory reference to coal and gas outburst prediction, coal seam gas content prediction and its exploitation and utilization.

scholarly journals An explanation of large-scale coal and gas outbursts in underground coal mines: the effect of low-permeability zones on abnormally abundant gas

2013 ◽  
Vol 1 (5) ◽  
pp. 4751-4775 ◽  
Author(s):  
F. H. An ◽  
Y. P. Cheng
Keyword(s):  
Coal Seam ◽  
Large Scale ◽  
Gas Pressure ◽  
Underground Mines ◽  
Low Permeability ◽  
Gas Distribution ◽  
Coal Gas ◽  
Annular Zone ◽  
Wall Deformation ◽  
Coal And Gas Outbursts

Abstract. Large-scale coal and gas outbursts post a risk of fatal disasters in underground mines. Large-scale outbursts (outburst of coal and rock greater than 500 t) in recent years in China indicate that there is abundant gas in areas of outbursts containing large amounts of potential energy. The adequate sealing properties of the roof and floor of a coal seam are required for local abundant gas around the site of an outburst, but an annular low-permeability zone in a coal seam, which prevents the loss by gas migration through the coal seam itself, is also required. The distribution of coal gas with this annular zone of low permeability is described, and it is proposed that the annular zone of low permeability creates conditions for confining the coal gas. The effect of this low-permeability zone on the gas distribution is analyzed after allowing for simplifications in the model. The results show that the permeability and length of the low-permeability zone have a great impact on the gas distribution. A steep gradient of gas pressure in the low-permeability zone and the high gas pressure in the abundant zone of gas can promote coal mass failure and coal wall deformation, thereby accelerating the coal and gas outburst. The high pressure gas in abundant zone of gas will lead to a large-scale outburst if an outburst occurs.

The Effect Evaluation of Removing Outburst through Bedding and Layer-through Boreholes Combined Gas Drainage

2012 ◽  
Vol 256-259 ◽  
pp. 366-371
Author(s):  
Zhong Ming Zhao ◽  
Lei Wang ◽  
Jian Bang Wu
Keyword(s):  
Gas Pressure ◽  
Gas Content ◽  
Effect Evaluation ◽  
Prevention Measures ◽  
Gas Drainage ◽  
Residual Gas ◽  
Favorable Conditions

In order to test the validity of regional outburst prevention measures that combined the bedding boreholes and layer-through boreholes in 3104 coalface, according to the relevant provisions, used drilling index, pre-pumping index and gas index to evaluate the effect of removing outburst in 3104 coalface. The evaluation results shown that through the pre-pumping gas, the rate of pre-pumping gas was 53.7%, more than 30%; residual gas content was 2.85～5.07m3/t, less than 8m3/t; residual gas pressure was 0.01～0.02MPa, less than 0.74 MPa. Therefore, the coalface has eliminated the danger of outburst and created favorable conditions for safety mining.

scholarly journals Experimental Study of the Characteristic Changes of Coal Resistivity during the Gas Adsorption/Desorption Process

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Zengchao Feng ◽  
Chen Wang ◽  
Dong Dong ◽  
Dong Zhao ◽  
Dong Zhou
Keyword(s):  
Gas Adsorption ◽  
Gas Content ◽  
Resistivity Change ◽  
Adsorption Experiment ◽  
Desorption Process ◽  
Continuous Adsorption ◽  
Gas Desorption ◽  
Original Figure ◽  
Adsorption Desorption ◽  
The Relationship

To study the influence of gas adsorption-desorption on the resistivity of coal, the resistivity changes in conditions of continuous adsorption/desorption and isovolumetric adsorption/desorption were tested by high-precision resistance measurement, and the relationship between coal resistivity and gas content was investigated. The results show that gas adsorption/desorption has obvious effects on the resistivity of coal. Similar behavior was observed both in continuous adsorption/desorption and in isovolumetric adsorption/desorption experiments. The coal resistivity decreased gradually at the very beginning and then tended to stabilize as the gas adsorption capacity increased; in the process of gas desorption, the resistivity demonstrated a linear relationship with gas content. When comparing resistivities for the different adsorption modes, it was found that, for the same gas content in each mode, the resistivity change in the isovolumetric adsorption experiment was more obvious than in the continuous adsorption experiment. Also, the coal resistivity in the isovolumetric experiment differed further from the original figure when the desorption ended. The results are significant for predicting gas content in the coal mining process.

Prediction method for risks of coal and gas outbursts based on spatial chaos theory using gas desorption index of drill cuttings

2011 ◽  
Vol 21 (3) ◽  
pp. 439-443 ◽  
Author(s):  
Dingqi Li ◽  
Yuanping Cheng ◽  
Lei Wang ◽  
Haifeng Wang ◽  
Liang Wang ◽  
...  
Keyword(s):  
Chaos Theory ◽  
Prediction Method ◽  
Drill Cuttings ◽  
Gas Desorption ◽  
Spatial Chaos ◽  
Coal And Gas Outbursts

Analysis of the Natural Methane Content of Boldyrevsky Seam at S.M. Kirov Mine of JSC SUEK-Kuzbass

2021 ◽  
pp. 61-66
Author(s):  
E.V. Fedorov ◽  
◽  
S.B. Kulibaba ◽  
A.A. Meshkov ◽  
◽  
...  
Keyword(s):  
Methane Content ◽  
Actual Data ◽  
Gas Content ◽  
Coal Seams ◽  
Actual Distribution ◽  
Coal Gas ◽  
Residual Gas ◽  
Mine Workings ◽  
Host Rocks

S.M. Kirov mine of JSC SUEK-Kuzbass develops Boldyrevsky and Polenovsky seams and is classified as a super-category for methane. Under these conditions, the development of seams requires a set of measures for their degassing. Methods and parameters for degassing the main sources of methane release in the coal mines are selected considering the faces gas content. It is calculated based on the natural methane content of the coal seams and host rocks determined at the stage of geologic exploration activity. The aim of the work conducted by the authors is to establish the actual distribution of natural methane seam Boldyrevsky based on the analysis of research results of the coal-gas samples and experimental evaluation of the residual gas content in the mine workings. Natural gas content of the mine field of S.M. Kirov JSC SUEK-Kuzbass mine was determined based on the analysis of 538 coal-gas samples on 30 seams. All the coal and gas samples taken from Boldyrevsky seam were analyzed. Distribution of the actual values of natural methane content from the hypsometric depths of the seam was plotted. Distribution was plotted concerning the actual values of natural methane from hypsometric depths of the formation. The obtained data were compared with the results of experimental determination of the residual gas content of Boldyrevsky seam from the mine workings. Based on the results obtained, CH4 isogases were constructed based on the actual and maximum values of the natural methane content in Boldyrevsky seam. It is established that the natural methane content of Boldyrevsky seam, that was determined at the stage of geological exploration for the entire field of S.V. Kirov mine, has overestimated values — by 35–40 % compared to the actual data, and by 25–30% in relation to the maximum actual data.

Research on the Relationship between the Drilling Cutting Gas Desorption Index △h2 and Parameters of Gas Occurrence

2011 ◽  
Vol 99-100 ◽  
pp. 1312-1318 ◽  
Author(s):  
Jian Liang Gao ◽  
Yu Wang
Keyword(s):  
Diffusion Coefficient ◽  
Linear Relationship ◽  
Gas Diffusion ◽  
Gas Pressure ◽  
Diffusion Resistance ◽  
Power Relationship ◽  
Gas Desorption ◽  
Coal Particles ◽  
Gas Occurrence ◽  
The Relationship

The drilling cutting gas desorption index △h2is one of the most important indexes for the prediction of coal and gas outburst. Based on the mathematical and physical model of the gas diffusion of coal particles, the analytical solution of △h2was deduced. The relationship between the drilling cutting gas desorption index △h2and parameters of gas occurrence such as the gas diffusion coefficient, adsorption constants (a and b), gas pressure, and gaSubscript textSubscript texts content were studied. The results show that △h2increases and gas diffusion resistance decreases with the gas diffusion coefficient. The drilling cutting gas desorption index △h2increases with the adsorption constant a, and the two meet the linear relationship. △h2increases with the adsorption constant b and the raising rate gets lower gradually. And, △h2increases with the gas pressure, and the two meet the power relationship with very high correlation coefficient.△h2and gas content are in linear relationship.

The Application of Crossing and Grid Drainage Boreholes in Floor Tunnel for Coal Roadway Safety Tunneling

2014 ◽  
Vol 962-965 ◽  
pp. 1169-1174
Author(s):  
Hong Qing Zhu ◽  
Bei Fang Gu ◽  
Min Bo Zhang ◽  
Chao Yu ◽  
Zhen Zhang
Keyword(s):  
Coal Seam ◽  
Gas Pressure ◽  
Gas Content ◽  
Dynamic Phenomenon ◽  
Coal Seams ◽  
Coal Seam Gas ◽  
Technical Parameters ◽  
Coal Roadway ◽  
Roadway Safety ◽  
The Relationship

In order to reduce the danger of single coal seams outburst during the tunneling in coal roadway and ensure the tunneling of coal seams, this text analyzed the mechanism of crossing drilling against outburst; studied the area measures of floor tunnel crossing and grid drainage boreholes in coal roadway, Designed and optimized the drilling technical parameters; Analyzed the relationship between the drainage concentration and scalar; Calculated the maximum overlying coal seam gas to spare scalar quantity is 224300 m3 ;Used a variety of indicators to investigate the effect of outburst prevention. It shows that Gas content and gas pressure have significant lower than drainage. After the drainage up to standard, all the sensitive indexes is not overrun, during the coal roadway tunneling, it does not appears dynamic phenomenon. Solve the problem of mining imbalances, guaranteed the safety driving of roadway.

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