scholarly journals Discussion on the Mechanism of Coal and Gas Outburst Prevention and Control by the Coal Seam Water Injection

2019 ◽  
Vol 252 ◽  
pp. 052090 ◽  
Author(s):  
Jufeng Zhang ◽  
Riyun Wang ◽  
Fengfeng Yang ◽  
Wulin Lei ◽  
Biyang Feng ◽  
...  
Keyword(s):  
Coal Seam ◽  
Prevention And Control ◽  
Water Injection ◽  
Coal And Gas Outburst ◽  
Gas Outburst ◽  
And Control

scholarly journals Cause Analysis and Prevention of Hole Collapse by Water Injection and Dust Removal in Qi Panjing Coal Mine

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Hua Guo ◽  
Hai-Qiao Wang ◽  
Shi-Qiang Chen ◽  
Zhi-Rong Wu
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Prevention And Control ◽  
Water Injection ◽  
Economic Benefits ◽  
Dust Removal ◽  
Drilling Depth ◽  
Key Technologies ◽  
Complete Set ◽  
And Control

To solve the “special coal seam” with complex coal seam structure, fault phenomenon, and many gangue layers and complex gangue lithology in Qi Panjing coal mine, the problems such as hole collapse and blockage of coal seam water injection dust removal drilling are caused. From the aspects of drilling layout, drilling technology, and gangue material consolidation, a complete set of key technologies for prevention and control of water injection and dust removal in “special coal seam,” have been formed. Seven boreholes have been drilled in I020902 return air roadway of Qi Panjing coal mine, and field comparative test has been carried out. The results show that: after adopting the complete set of key technologies of drilling prevention and control, the drilling depth is 85-100 m, the average depth is 98 m, and the drilling depth of coal seam water injection can reach 170-185 m; the footage per cycle is greatly improved, with the minimum increase of 30.86%, the maximum increase of 46.38%, and the average increase of 36.77%, to save drilling time and bring good economic benefits, and there is no collapse in the borehole hole, to ensure the safety of production. It has a good reference, and practical guiding significance for other coal mining faces, especially for “special coal seam” working face.

scholarly journals A Continuous Dynamic Prediction Model of Gas Pressure Based on Gas Emission at Excavation Face and its Engineering Application

2016 ◽  
Author(s):  
Chen Liang ◽  
Wang Enyuan
Keyword(s):  
Prediction Model ◽  
Prevention And Control ◽  
Engineering Application ◽  
Dynamic Effect ◽  
Gas Pressure ◽  
Coal And Gas Outburst ◽  
Gas Emission ◽  
Dynamic Prediction ◽  
Gas Outburst ◽  
And Control

Abstract. Gas pressure is one of the necessary conditions for the occurrence of coal and gas outburst. Realization of continuous and dynamic gas pressure forecasting is of significance for prevention and control of coal and gas outburst. In this work, we established a gas pressure prediction model based on the source of gas emission with considering fluid-solid coupling process. The verified results showed that the predicted gas pressure was roughly consistent with the actual situation, indicating that the prediction model is correct. And it could meet the need of engineering projects. Coal and gas outburst dynamic phenomenon is successfully predicted in engineering application with the model. Overall, prediction coal and gas outburst with the gas pressure model can achieve the continuous and dynamic effect. It can overcome both the static and sampling shortcomings of traditional methods, and solve the difficulty of coal and gas outburst prediction at the excavation face. With its broad applicability and potential prospect, we believe the model is of great importance for improving prevention and control of gas disasters.

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]

3D Visualization of Coal Seam Gas Distribution State

2014 ◽  
Vol 577 ◽  
pp. 1077-1082
Author(s):  
Gen Yin Cheng ◽  
Shan Feng ◽  
You Cheng
Keyword(s):  
Coal Seam ◽  
Prevention And Control ◽  
3D Visualization ◽  
Three Dimensional ◽  
Three Dimension ◽  
Gas Distribution ◽  
Coal Seam Gas ◽  
Reducing Gas ◽  
Distribution State ◽  
And Control

The monitoring of gas distribution state of coal seam could efficiently prevent gas accidents in coal mine, but the currently researches are mostly focus on qualitative assessments. Through the three-dimension character analysis of gas distribution state of coal seam, we could build a three-dimension model of gas distribution state of coal seam, and then make its visualization through the simulation of computer. It makes the gas distribution state of coal seam more intuitive. This study could make the analysis of gas distribution state more scientific and provides a three-dimensional visualization platform for the prevention and control of gas, reducing gas accidents.

scholarly journals Prevention and Control of Hydrogen Sulphide Accidents in Mining Extremely Thick Coal Seam: A Case Study in Wudong Coal Mine

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xuchao Huang ◽  
Enmao Wang ◽  
Gang Wang ◽  
Jiuyuan Fan
Keyword(s):  
Molecular Weight ◽  
Coal Seam ◽  
Hydrogen Sulphide ◽  
Coal Mine ◽  
Prevention And Control ◽  
Coal Mines ◽  
Dynamics Simulation ◽  
Porous System ◽  
Coal Stratum ◽  
And Control

Hydrogen sulphide is a toxic gas often present in coal seams and seriously threatens the lives and health of underground workers in coal mines. In this study, we theoretically modelled hydrogen sulphide generation in extremely thick underground coal mines with the +575 level #45 coal seam of Wudong Coal Mine as an example and obtained the on-site hydrogen sulphide emission pattern and spatial distribution features by combining field measurements and computational fluid dynamics simulation. The results showed that hydrogen sulphide mainly exists in the coal porous system in an adsorbed state. Because hydrogen sulphide has a molecular weight greater than the average molecular weight of air molecules, its concentration decreases with the increase of altitude to the bottom plate. When mining the upper stratified coal stratum, it diffuses widely in the working space; while when mining the lower coal stratum, it mainly concentrates at the bottom of the working face. Based on these analyses, on-site treatments were carried out using mixtures with different concentrations of sodium carbonate and sodium bicarbonate. In addition, different combinations of catalysts as well as type A and type B wetting agents were also tested. Eventually, a neutral KXL-I absorbent was developed, and the process of preinjecting absorbent and spraying absorbent was designed. The results showed that the newly developed KXL-I absorbent has high hydrogen sulphide absorption ability and is suitable for use as an absorbent in Wudong Coal Mine; preinjecting and spraying the absorbent can effectively prevent hydrogen sulphide disasters in the +575 level #45 coal seam in Wudong Coal Mine with the optimal final concentration of 0.9% and the absorption rate of 87% at the shearer of 66.6% at the support. Overall, our study provides valuable information for the prevention and control of hydrogen sulphide disasters in coal mines.

scholarly journals Risk assessment method of coal and gas outburst based on improved comprehensive weighting and cloud theory

2021 ◽  
pp. 014459872110558
Author(s):  
Chunhua Zhang ◽  
Dengming Jiao ◽  
Ziwen Dong ◽  
Hongyu Zhang
Keyword(s):  
Risk Assessment ◽  
Coal Seam ◽  
Ideal Point ◽  
Assessment Method ◽  
Coal And Gas Outburst ◽  
Coal Seams ◽  
Gas Outburst ◽  
Risk Assessment Method ◽  
Cloud Theory ◽  
Assessment Results

Risk assessment is an effective method of accident prevention and is vital to actual production. To reduce the risk of mining accidents and realize green and sustainable coal mining, a coal and gas outburst risk assessment method based on the improved comprehensive weight and cloud theory is proposed. The proposed method can effectively solve problems of fuzziness and randomness, index weight deviation, and correlation between indexes in risk assessment, as well as improve the accuracy and rationality of assessment. Nine influencing factors that correspond to coal seam occurrence and geological characteristics, coal seam physical characteristics, and gas occurrence characteristics are selected to establish the risk assessment index system of coal and gas outburst. Using the improved group G1 method and improved CRITIC method to obtain the subjective and objective weights, the ideal point method is used to obtain the comprehensive weight. Using the normal cloud model of cloud theory and the comprehensive weight to assess engineering examples 1–2, the No. 3 coal seam of a mine in Shanxi, and the 21 coal seam of a mine in Henan, the risk grade of coal and gas outburst is determined and then compared with the assessment results obtained from the engineering examples and the actual situations of the above mentioned coal seams. The results show that the coal and gas outburst risks of engineering examples 1–2, No. 3 coal seam, and 21 coal seam are of grades IV, IV, II, and IV, respectively. The No. 3 coal seam and 21 coal seam belong to lower and higher risk categories, respectively. The assessment results are consistent with the actual situation of the coal seams, thereby confirming the rationality and accuracy of the proposed method. This study expands the methods of coal and gas outburst risk assessment and facilitates the formulation of effective preventive measures.

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