scholarly journals Research on the Coal Seam Permeability-Increasing Technology via High-Pressure Water Jet Reaming and Its Application

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xingang Niu ◽  
Biming Shi ◽  
Zhigang Zhang ◽  
Yongjiang Zhang
Keyword(s):  
High Pressure ◽  
Coal Seam ◽  
Water Jet ◽  
Pulverized Coal ◽  
Gas Drainage ◽  
Drainage Volume ◽  
Single Hole ◽  
Drainage Rate ◽  
Pressure Water ◽  
Conventional Drilling

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.

Design of Drilling-Slotting Equipment with High-Pressure Water Jet for Coal Bed

2012 ◽  
Vol 619 ◽  
pp. 213-217
Author(s):  
Zhi Tang ◽  
Yi Shan Pan ◽  
Shao Qi Gong ◽  
Ju Peng Tang
Keyword(s):  
High Pressure ◽  
High Stress ◽  
Water Jet ◽  
Coal Bed ◽  
Noise Elimination ◽  
Gas Drainage ◽  
Drainage Rate ◽  
The Press ◽  
Pressure Water ◽  
High Pressure Water Jet

Aiming at the problems of high stress, poor permeability and low gas drainage rate in deep mining, An integrative equipment is designed with high-pressure water jet, based on the principle of drilling, slotting, pressure relief and improving permeability together with the high-pressure water jet. This equipment can realize high-pressure drilling, low pressure punching, 360° high-pressure slotting and so on. In the multifunctional spray head, more slotting nozzle sections improve the slotting efficiency; also enhance the press-relief and permeability effect. The noise elimination cover decreases machine noise and improves the work environment. This equipment has important significance to improve gas drainage rate and prevent the dynamic catastrophe of the coal-bed.

scholarly journals Permeability Enhancement Properties of High-Pressure Abrasive Water Jet Flushing and Its Application in a Soft Coal Seam

2021 ◽  
Vol 9 ◽  
Author(s):  
Xinzhe Zhang ◽  
Piotr Wiśniewski ◽  
Sławomir Dykas ◽  
Guojie Zhang
Keyword(s):  
High Pressure ◽  
Coal Seam ◽  
Water Jet ◽  
Gas Pressure ◽  
Theory And Practice ◽  
Abrasive Water Jet ◽  
Gas Drainage ◽  
Permeability Enhancement ◽  
Soft Coal ◽  
Soft Coal Seam

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.

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
Keyword(s):  
High Pressure ◽  
Coal Seam ◽  
Water Injection ◽  
Mine Safety ◽  
Gas Drainage ◽  
Damage Area ◽  
Major Disaster ◽  
Before And After ◽  
Pressure Water ◽  
Injection Technology

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.

scholarly journals Engineering Practice of Ultra-high Pressure Hydraulic Slotting and Pressure Relief Pumping in Through Layer Hole

2021 ◽  
Vol 236 ◽  
pp. 01029
Author(s):  
Siqian Li
Keyword(s):  
High Pressure ◽  
Coal Seam ◽  
High Efficiency ◽  
Engineering Practice ◽  
Pressure Relief ◽  
Gas Drainage ◽  
Thick Coal Seam ◽  
Ultra High Pressure ◽  
Drainage Rate ◽  
Gas Control

In order to solve the problems of low gas drainage rate and long drainage time in thick coal seam with low permeability, ultra-high pressure hydraulic slotting pressure relief and permeability enhancement technology was applied in the test. The practice shows that after adopting the ultra-high pressure hydraulic slotting, the gas drainage rate is greatly improved, the time for reaching the standard of drainage is shortened, and the difficult problem of gas control in the mining face of thick coal seam is solved, which provides technical guidance for high-efficiency gas control in thick coal seam with similar conditions in mining area.

Research and Apply the Technique of Dip Rock Cross-Cut Uncovering Serious Outburst Coal Seam Group

2013 ◽  
Vol 868 ◽  
pp. 356-360
Author(s):  
Jun Liu
Keyword(s):  
High Pressure ◽  
Coal Seam ◽  
Coal Dust ◽  
Water Jet ◽  
Pressure Relief ◽  
Dust Extraction ◽  
Pressure Water ◽  
High Pressure Water Jet ◽  
Outburst Coal Seam ◽  
Integrated Technique

Apply high pressure water jet drilling and reaming integrated technique to research the technique of dip cross-cut uncovering serious outburst coal seam group; numerical simulation by FLAC3D concludes that how much the diameters be after being reamed can get relief pressure well at different hole spacing; it shows that the technique expands pressure relief range, increases the permeability of coal and improves the drainage efficient at uncovering coal area in the experiment. Improve the craft and equipment of high pressure water jet drilling and reaming integrated technique, solve the problem of coal dust extraction difficultly at the dip hole, prolong high pressure and rotating joints life; the research indicates that high pressure water jet drilling and reaming integrated technique gets well effect on uncovering coals speed and outburst prevention effect, its of promotion application value to uncovering coal safely and efficiently in mine.

scholarly journals Study on Pressure Relief Technology of High-Pressure Water Jet of Residual Coal Pillar in Overlying Goaf in Close Seam Mining

2022 ◽  
Vol 2022 ◽  
pp. 1-19
Author(s):  
Shang Yang ◽  
Xuehui Li ◽  
Jun Wang ◽  
Shuhao Yang ◽  
Zhen Shen ◽  
...  
Keyword(s):  
High Pressure ◽  
Coal Seam ◽  
Coal Pillar ◽  
Water Jet ◽  
Hydraulic Support ◽  
Working Face ◽  
Pressure Water ◽  
High Pressure Water Jet ◽  
Residual Coal ◽  
Close Distance

To solve the problem of strong ground pressure behaviour under a residual coal pillar in the overlying goaf of a close-distance coal seam, this paper proposes the technology of weakening and relieving the residual coal pillar in the overlying goaf by a high-pressure water jet. Based on the geological occurrence of the No. 3 coal seam and mountain No. 4 coal seam in the Yanzishan coal mine, the high-pressure water jet pressure relief technology of residual coal pillars in the overlying goaf of close-distance coal seams was studied by theoretical analysis and field industrial tests. First, the elastic-plastic zone of the residual coal pillar and the stress distribution law of the floor are obtained by theoretical analysis, and the influence degree of the residual coal pillar on the support of the lower coal seam working face is revealed. Then, a high-pressure water jet combined with mine pressure is proposed to weaken the residual coal pillar. Finally, through the residual coal pillar hydraulic cutting mechanical model and “double-drilling double-slot” model, the high-pressure water jet drilling layout parameters are determined, and an industrial field test is carried out. The single knife cutting coal output and 38216 working face hydraulic support monitoring data show that high-pressure hydraulic slotting can weaken the strength of the coal body to a certain extent, destroy the integrity of the residual coal pillar, cut off the load transmission path of the overlying strata, and reduce the working resistance of the hydraulic support under the residual coal pillar to a certain extent, which is beneficial to the safe mining of the working face.

Investigation of High Pressure Water Jet with Hydraulic Reaming Drainage Radius for Coal Seam Mining

2012 ◽  
Vol 577 ◽  
pp. 147-150 ◽  
Author(s):  
Yong Jiang Zhang ◽  
Xian Zheng Meng ◽  
Jian Jun Cao
Keyword(s):  
High Pressure ◽  
Coal Seam ◽  
Water Jet ◽  
Gas Pressure ◽  
Coal Extraction ◽  
Drainage Radius ◽  
Pressure Water ◽  
New Type ◽  
High Pressure Water Jet ◽  
Seam Mining

Test mine is a large modern mine, the 13-1 coal-seam original permeability coefficient was low, gas pressure and content were higher, coal seam outburst danger of serious, directly extracting coal gas is difficult. Using a new type of high pressure water jet reaming technology, can achieve the expansion of borehole diameter, increase coal seam exposed area and pressure relief range, thereby improving the coal seam permeability, increased coal seam drainage radius. Investigated on the basis of determination of the original coal seam gas pressure and content of the coal extraction radius after the hydraulic reaming. Provide the basis for the seam of the test area borehole design

scholarly journals Design and Optimization of High-Pressure Water Jet for Coal Breaking and Punching Nozzle Considering Structural Parameter Interaction

Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 60
Author(s):  
Lihuan Chen ◽  
Muzheng Cheng ◽  
Yi Cai ◽  
Liwen Guo ◽  
Dianrong Gao
Keyword(s):  
High Pressure ◽  
Coal Seam ◽  
Structural Parameters ◽  
Water Jet ◽  
Diameter Ratio ◽  
Divergence Angle ◽  
Pressure Water ◽  
High Pressure Water Jet ◽  
Contraction Angle ◽  
Length To Diameter Ratio

The technology of increasing coal seam permeability by high-pressure water jet has significant advantages in preventing and controlling gas disasters in low-permeability coal seam. The structural parameters of a nozzle are the key to its jet performance. The majority of the current studies take strike velocity as the evaluation index, and the influence of the interaction between the nozzle’s structural parameters on its jet performance is not fully considered. In practice, strike velocity and strike area will affect gas release in the process of coal breaking and punching. To further optimize the structural parameters of coal breaking and punching nozzle, and improve water jet performance, some crucial parameters such as the contraction angle, outlet divergence angle, and length-to-diameter ratio are selected. Meanwhile, the maximum X-axis velocity and effective Y-axis extension distance are used as evaluation indexes. The effect of each key factor on the water jet performance is analyzed by numerical simulation using the single factor method. The significance and importance effect of each factor and their interaction on the water jet performance are quantitatively analyzed using the orthogonal experiment method. Moreover, three optimal combinations are selected for experimental verification. Results show that with an increase in contraction angle, outlet divergence angle, and length-to-diameter ratio, the maximum X-axis velocity increases initially and decreases thereafter. The Y-direction expansion distance of the jet will be improved significantly with an increase in the outlet divergence angle. Through field experiments, the jet performance of the improved nozzle 3 is the best. After optimization, the coal breaking and punching diameter of the nozzle is increased by 118%, and the punching depth is increased by 17.46%.

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