Calculation Model of High-Pressure Water Jet Slotting Depth for Coalbed Methane Development in Underground Coal Mine
| Autor: | Jianguo Zhang, Xiaobo Huang, Zhaolong Ge, Hanyun Zhao, Songqiang Xiao, Yingwei Wang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
animal structures
Coalbed methane Nozzle 0211 other engineering and technologies Borehole ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ComputerApplications_COMPUTERSINOTHERSYSTEMS 02 engineering and technology gas drainage 010502 geochemistry & geophysics 01 natural sciences complex mixtures GeneralLiterature_MISCELLANEOUS Coal gas otorhinolaryngologic diseases coal and gas outburst General Materials Science water jet slotting Instrumentation 021101 geological & geomatics engineering 0105 earth and related environmental sciences ComputingMethodologies_COMPUTERGRAPHICS Fluid Flow and Transfer Processes High pressure water Petroleum engineering business.industry Process Chemistry and Technology General Engineering Coal mining Rotational speed respiratory system Computer Science Applications respiratory tract diseases Permeability (earth sciences) slotting depth Environmental science business |
| Zdroj: | Applied Sciences Volume 9 Issue 23 |
| ISSN: | 2076-3417 |
| DOI: | 10.3390/app9235250 |
| Popis: | In underground coal mines, high-pressure water jet slotting is effective at improving coal seams&rsquo permeability. The slotting depth determines the effect of pressure relief and permeability enhancement in coal seams. However, there is no effective and feasible way of determining the slotting depth thus, the operational parameters and borehole layout are unknown. This study determined the effects of key parameters, including the nozzle diameter, jet pressure, rotation speed, and slotting time, on the slotting depth. A water jet slotting depth calculation model was established and verified according to the slotting experiments under different operational conditions. The slotting depths were investigated based on the results of field slotting experiments. The results revealed that there exists an optimal nozzle diameter for a higher jet impact velocity. The slotting depth linearly increased with the jet pressure and decreased as a power function with the increase of the jet translation speed. The slotting depth increased with the slotting time, but the growth rate gradually decreased and tended to be stable. As the rotation speed increased, the slotting depth became greater at the initial period and the limit depth was reached faster. Laboratory and field slotting experiments were conducted to verify the model, and the experimental results are approximately in agreement with the theoretical predictions. The results of this study can be useful as guidelines for the hydraulic parameter selection of water jet slotting and for optimizing the layout of coal gas drainage boreholes. |
| Databáze: | OpenAIRE |
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