Dissolution characteristics of gas in mine water and its application on gas pressure measurement of water-intrusion coal seam

Fuel ◽  
2022 ◽  
Vol 313 ◽  
pp. 123004
Author(s):  
Leilei Si ◽  
Yujun Xi ◽  
Jianping Wei ◽  
Bo Li ◽  
Hongyang Wang ◽  
...  
2017 ◽  
Vol 119 (1) ◽  
pp. 163-179 ◽  
Author(s):  
Leilei Si ◽  
Zenghua Li ◽  
Dingzhi Xue ◽  
Jun Zhou ◽  
Yongliang Yang ◽  
...  

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Shen Liu ◽  
Yiping Wang ◽  
Changrui Liao ◽  
Ying Wang ◽  
Jun He ◽  
...  

2021 ◽  
Vol 9 ◽  
Author(s):  
Xinzhe Zhang ◽  
Piotr Wiśniewski ◽  
Sławomir Dykas ◽  
Guojie Zhang

High-pressure abrasive water jet flushing (HPAWJF) is an effective method used to improve coal seam permeability. In this study, based on the theories of gas flow and coal deformation, a coupled gas-rock model is established to investigate realistic failure processes by introducing equations for the evolution of mesoscopic element damage along with coal mass deformation. Numerical simulation of the failure and pressure relief processes is carried out under different coal seam permeability and flushing length conditions. Distributions of the seepage and gas pressure fields of the realistic failure process are analyzed. The effects of flushing permeability enhancement in a soft coal seam on the gas drainage from boreholes are revealed by conducting a field experiment. Conclusions can be extracted that the gas pressure of the slotted soft coal seam is reduced and that the gas drainage volume is three times higher than that of a conventional borehole. Field tests demonstrate that the gas drainage effect of the soft coal seam is significantly improved and that tunneling speed is nearly doubled. The results obtained from this study can provide guidance to gas drainage in soft coal seams regarding the theory and practice application of the HPAWJF method.


2012 ◽  
Vol 24 (10) ◽  
pp. 2343-2346
Author(s):  
林伟 Lin Wei ◽  
王凯 Wang Kai ◽  
毕鹏 Bi Peng ◽  
黎军 Li Jun ◽  
马坤全 Ma Kunquan ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yujia Chen ◽  
Ao Li ◽  
Dingding Yang ◽  
Tianyu Liu ◽  
Xiaowei Li ◽  
...  

In order to ensure the intactness of pressure-measuring boreholes and the accuracy of gas pressure determination, pregrouting treatment with polymer materials is frequently applied to bedding drilling in coal mines. However, the existing polyurethane materials are of high viscosity, low permeability, and poor safety, bringing great difficulties to their field promotion and application. In view of this problem, after optimization and experiments, polylactide polyol/polyether polyol 4110/isocyanate was determined as the target system. Bio-based benzoxazine (Boz-F), red phosphorus, and melamine with a mass ratio of 2 : 1 : 2 were used as the flame retardant, which then underwent mechanical modification by hollow glass bubbles. Finally, the pregrouting material with low viscosity and high permeability was compounded, and its interaction with coal was experimentally studied. The results show that compared with traditional polyurethane, the new material increases the effective consolidation distance in the coal seam by 40% on average. Its permeation radius is also larger than the calculated radius of the plastic softening zone of a borehole. In addition, the strengths of coal-new material consolidated products with different ratios fully surpass those of coal-polyurethane material consolidated products. The enhancement of compressive strength and bending strength is up to 153% and 161%, respectively. The field application indicates that after pregrouting treatment of boreholes in the coal seam with the new material, the borehole formation rate reaches 100%. Therefore, the new material is safe and practical for gas pressure measurement through bedding drilling on site.


Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2387 ◽  
Author(s):  
Bo Zhang ◽  
Yong Li ◽  
Nicholas Fantuzzi ◽  
Yuan Zhao ◽  
Yan-Bao Liu ◽  
...  

Coal contains a large number of fractures, whose characteristics are difficult to describe in detail, while their spatial distribution patterns may follow some macroscopic statistical laws. In this paper, several fracture geometric parameters (FGPs) were used to describe a fracture, and the coal seam was represented by a two-dimensional stochastic fracture network (SFN) which was generated and processed through a series of methods in MATLAB. Then, the processed SFN image was able to be imported into COMSOL Multiphysics and converted to a computational domain through the image function. In this way, the influences of different FGPs and their distribution patterns on the permeability of the coal seam were studied, and a finite element model to investigate gas flow properties in the coal seam was carried out. The results show that the permeability of the coal seam increased with the rising of fracture density, length, aperture, and with the decrease of the angle between the fracture orientation and the gas pressure gradient. It has also been found that large-sized fractures have a more significant contribution to coal reservoir permeability. Additionally, a numerical simulation of CBM extraction was carried out to show the potential of the proposed approach in the application of tackling practical engineering problems. According to the results, not only the connectivity of fractures but also variations of gas pressure and velocity can be displayed explicitly, which is consistent well with the actual situation.


2017 ◽  
Vol 45 ◽  
pp. 502-510 ◽  
Author(s):  
Chaojie Wang ◽  
Shengqiang Yang ◽  
Chenglin Jiang ◽  
Dingding Yang ◽  
Chaojie Zhang ◽  
...  

2020 ◽  
Vol 244 ◽  
pp. 118646 ◽  
Author(s):  
Hongqing Song ◽  
Jianjian Xu ◽  
Jie Fang ◽  
Zhiguo Cao ◽  
Lianzhi Yang ◽  
...  

1959 ◽  
Vol 37 (12) ◽  
pp. 1331-1338
Author(s):  
W. R. Blackmore

A thermistor hypsometer used as a sensitive, recording, gas-pressure measuring device is described. It is shown that the limitation on this device is the noise introduced by the pressure fluctuations over the surface of the boiling liquid. These fluctuations are about ±(5–10) μ(microns) Hg peak-to-peak. When a pressure measurement is averaged over a moderately short period of time it may be estimated to ± 1 μHg.


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