Effective Methane Extraction Radius after High-Pressure Water Jet Slotting

Hu, Ke; Xia, Binwei; Liu, Chengwei; Lu, Yiyu

doi:10.1155/2020/8820540

Cited by 2 publications

(1 citation statement)

References 35 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Aiming at the high-pressure water jet technology, the main achievements are as follows. Ke et al [24] proposed a steady-state flow model and used it to calculate the effective radius after the high-pressure water jet is slotted. Field measurements at Zhongliangshan Coal Mine show that both the steady-state flow model and the thermal-hydraulic-mechanical coupling model can accurately represent the effective radius and the thermal-hydraulic-mechanical coupling model provides more information about the extraction time.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

View full text Add to dashboard Cite

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.

show abstract

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

View full text Add to dashboard Cite

show abstract

Morphological characteristics and permeability evolution of deep mine gas drainage boreholes

et al. 2022

View full text Add to dashboard Cite

Structural coal has low permeability and high gas content. The increase of mining depth seriously restricts the safe mining of deep mines. Hydraulic flushing is the main means of gas extraction. The shape of the hydraulic flushing hole is an important basis to determine the pumping radius, which is widely regarded as a cylinder. However, due to the differences in the stress level, water force, friction and external moisture, the pore morphology, and permeability evolution need to be further studied. At present, the hole shape for hydraulic punching is equivalent to a cylinder in drilling design and evaluation, which is one of the important bases to determine the effective extraction radius. However, the hole shape is affected by many factors, so the scientific equivalent to a cylinder remains to be discussed. The BR-PKN equation describing the hole shape is established by introducing and combining the Bergmark–Roos equation and PKN model, and the hole’s shape is shown by MATLAB. To verify its accuracy, YZD18.5 is used as an onsite logging tool for data acquisition and analysis, and the hole section is drawn. The BR-PKN equation and permeability evolution model are simulated by COMSOL Multiphysics, and the permeability evolution law of conventional cylinder with hydraulic flushing is compared and analyzed. The results show that 1) the shape of the hydraulic punch hole is ellipsoid with three different axes, and its horizontal section is approximately an ellipse; 2) within the influence range of quasi-ellipsoid holes, the permeability changes in the long and short axis of quasi-ellipsoid holes are similar. The permeability evolution curve of the coal first increases, then decreases, and finally, flattens with the increase of distance from borehole, and the permeability of the coal body increases with the extension of extraction time); 3) the permeability of the equivalent ellipsoid pore decreases with the increase in coal water content. The effective radius in the long and short axes of the minimum cross section of the quasi-ellipsoid hole is 0.89 and 0.95 times the effective extraction radius of the equivalent cylinder, which provides a basis for a drilling layout.

show abstract

Effective Methane Extraction Radius after High-Pressure Water Jet Slotting

Cited by 2 publications

References 35 publications

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

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

Morphological characteristics and permeability evolution of deep mine gas drainage boreholes

Contact Info

Product

Resources

About