Analysis on Gas Drainage Based on High-Pressure Water Injection

2012 ◽  
Vol 524-527 ◽  
pp. 1147-1152
Author(s):  
Chao Zheng ◽  
Tian Hong Yang ◽  
Qing Lei Yu ◽  
Peng Hai Zhang

Gas outburst has been a major disaster in high gas mine. Flow law of gas in coal seam was studied, and gas drainage measures were proposed were extraordinarily useful for mine safety and rational use of gas. Finite element numerical method was applied to study changing law of gas pressure before and after the high-pressure water injection and damage deformation of coal under high-pressure water based on fluid-solid coupling and gas-solid coupling and damage theory. This research shows that: (1) a damage area was generated in coal seam under high-pressure water injection. Range of the damage area increase rapidly at the start of water injection and gradually slow down with the passage of time, eventually be more stable. (2) The permeability of rock mass of coal under high-pressure water injection. (3) High-pressure water injection had significant effect on gas drainage in a certain area. It provided a theoretical basis for selecting reasonable design programs to product gas by high-pressure water injection technology.

Author(s):  
Dong Zhao ◽  
Dayuan Li ◽  
Yulin Ma ◽  
Zengchao Feng ◽  
Yangsheng Zhao

Moisture and thermal are the key factors for influencing methane desorption during CBM exploitation. Using high pressure water injection technology into coalbed, new fractures and pathways are formed to methane transport. It is existed a phenomenon of water inhibiting gas flow. This study is focused on various water pressures impacted on gas adsorbed coal samples, then the desorption capacity could be revealed under different conditions. And the results are shown that methane desorption capacity was decreased with water pressure increased at room temperature and the downtrend would be steady until water pressure was large enough. Heating could promote gas desorption capacity effectively, with the increasing of water injection pressures, the promotion of thermal on desorption became more obvious. There are the others effects on methane desorption capacity influenced by water injection and thermal.


2012 ◽  
Vol 524-527 ◽  
pp. 690-693
Author(s):  
Gu Sheng Tong ◽  
Yong Sheng Liu

Coal and gas bursting is an important factor of causing coal mine safety accident, it may cause major accident, even effect on the safety of human life. Human disturbance is an important factor of causing coal and gas outburst. In this paper under the enlightenment of the water injection dustproof, the coal technology of static high pressure water expanding were researched and developed. And the main equipment of coal and the process flow and the mechanism of rock breaking and the matters needing attention were introduced. Field application showed that the technology can decrease the outburst of the coal and gas and can increase the driving speed. So the technology is effective method of coal mining.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xingang Niu ◽  
Biming Shi ◽  
Zhigang Zhang ◽  
Yongjiang Zhang

Aiming at the problem of coal and gas outburst prevention and control in serious outburst dangerous coal seam under complex geological conditions in Qidong Coal Mine, the water jet drilling and expanding integrated device was used to implement the measures that expand holes and increase permeability by high-pressure water at a 912 working face. The experimental results show that when the pump pressure is between 13 MPa and 15 MPa, the particle size of pulverized coal can be effectively reduced and the discharge of pulverized coal can be increased. The coal output of a single hole is 0.8~2.3 t/m, with an average of 1.1 m/t. The unreamed conventional borehole has a single-hole initial gas drainage rate of 50.74 m3/d and a single-hole cumulative gas drainage rate of 736.12 m3 within 30 days. The initial single-hole gas drainage volume of the reaming borehole is 178.74 m3/d, and the cumulative single-hole gas drainage volume in 30 days is 2227.57 m3. After reaming, the initial gas drainage scalar of a single hole increases 3.52 times of the original unreamed conventional drilling and the average cumulative gas drainage scalar of a single hole reaches 3.03 times of the original unreamed conventional drilling. This technology and equipment have a good promotion and application value in gas treatment of soft, low-permeable coal seams.


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 50 (4) ◽  
pp. 851-856 ◽  
Author(s):  
Wei-min Cheng ◽  
Wen Nie ◽  
Gang Zhou ◽  
Yanbin Yu ◽  
Youying Ma ◽  
...  

2012 ◽  
Vol 524-527 ◽  
pp. 1190-1195
Author(s):  
Jian Jun Liu ◽  
Quan Shu Li ◽  
Gui Hong Pei

Channeling flow frequently occurs during the high pressure water injection of low permeability reservoir. The injection process is complex and covers so many parameters of which the contribution to channeling flow is necessarily to be studied. In this paper, numerical simulation is combined with sensitivity analysis method to calculate the significance of the weight of parameters to the channeling flow. First the values of different parameters are produced by using Latin hypercube method; second, by using these parameters, finite element model have been established and simulated, and the quantity of channeling flow has been calculated; then Spearman rank relation is applied to measure the relation of parameters and channeling flow. The results states that, in 10 years continuous injection, the well spacing and injection pressure have significant impact on the channeling flow. This states that during the application of high pressure water injection, the pressure and well spacing should be controlled especially.


Injury Extra ◽  
2006 ◽  
Vol 37 (11) ◽  
pp. 430-431
Author(s):  
Ross Hutchison ◽  
Imran Ilyas ◽  
Philip T. Munro

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