本文選題：松軟高突煤層 + 瓦斯抽采��； 參考：《北京科技大學(xué)》2017年博士論文

【摘要】：水力沖孔是提高礦井瓦斯抽采效果的關(guān)鍵技術(shù)之一。本文通過理論分析,構(gòu)建了水力沖孔瓦斯增透理論模型,揭示了水力沖孔卸壓增透機(jī)理。運(yùn)用COMSOL Multiphysics軟件對(duì)松軟高突煤層水力沖孔效果進(jìn)行了數(shù)值模擬,并基于電法響應(yīng)實(shí)驗(yàn)平臺(tái),構(gòu)建了水力沖孔評(píng)價(jià)系統(tǒng),提出了效果評(píng)價(jià)指標(biāo),且進(jìn)行了現(xiàn)場(chǎng)驗(yàn)證。具體如下:基于Hoek-Brown破壞準(zhǔn)則,分析了鉆孔周圍煤體力學(xué)性能,得出了沖孔后鉆孔卸壓區(qū)的變化規(guī)律;分析了水力沖孔裂縫生成、發(fā)育及擴(kuò)展過程,推導(dǎo)得出了裂縫擴(kuò)展長度計(jì)算方程。結(jié)合質(zhì)量守恒方程、朗格繆爾方程及達(dá)西定律,建立了含瓦斯煤體滲流方程,并考慮到孔隙率和滲透率的動(dòng)態(tài)變化,構(gòu)建了鉆孔抽采瓦斯流固耦合模型。依據(jù)上述理論模型,應(yīng)用COMSOLMultiphysics軟件,對(duì)糯東煤礦水力沖孔卸壓增透效果進(jìn)行了數(shù)值模擬,得出了糯東煤礦水力沖孔沖出煤量1t/m、每排6孔、間距8.48m的布孔方案。為評(píng)價(jià)布孔方案現(xiàn)場(chǎng)應(yīng)用效果,基于直流電法響應(yīng),開發(fā)了水力沖孔實(shí)驗(yàn)室模擬系統(tǒng),通過實(shí)驗(yàn)室實(shí)驗(yàn),分析了載荷、水、裂隙對(duì)煤巖體視電阻率的影響,揭示了煤巖體在沖孔過程中視電阻率的變化規(guī)律。提出以視電阻率平均變化系數(shù)I作為水力沖孔抽采瓦斯效果評(píng)價(jià)指標(biāo),制定了水力沖孔效果評(píng)價(jià)分級(jí)標(biāo)準(zhǔn)。根據(jù)上述研究結(jié)果,對(duì)糯東煤礦17號(hào)煤層進(jìn)行了現(xiàn)場(chǎng)沖孔,并運(yùn)用直流電法對(duì)沖孔區(qū)域進(jìn)行了效果評(píng)價(jià)。結(jié)果表明,水力沖孔的有效影響范圍為:在深度上集中在-25m～-45m,在走向上集中在35m～75m,走向影響半徑約20m。測(cè)試區(qū)域視電阻率平均變化系數(shù)I=93%,水力化措施評(píng)價(jià)等級(jí)為Ⅱ級(jí),證明該區(qū)域水力沖孔卸壓增透瓦斯效果顯著。研究成果對(duì)松軟高突礦井的煤與瓦斯突出治理工作具有借鑒和參考意義,同時(shí)為全面有效評(píng)價(jià)瓦斯治理效果提供了科學(xué)依據(jù)和理論指導(dǎo)。
[Abstract]:Hydraulic punching is one of the key techniques to improve the effect of gas drainage.Based on the theoretical analysis, a theoretical model of hydraulic punching gas antitransmittance is constructed, and the mechanism of hydraulic punching pressure relief is revealed.The hydraulic punching effect of soft high outburst coal seam was simulated by COMSOL Multiphysics software. Based on the experimental platform of electric method response, the evaluation system of hydraulic punching was constructed, and the evaluation index was put forward, and the field verification was carried out.The main contents are as follows: based on the Hoek-Brown failure criterion, the mechanical properties of coal body around the borehole are analyzed, and the variation law of the pressure relief zone of the borehole after punching is obtained, and the process of formation, development and expansion of the cracks in hydraulic punching hole is analyzed.The calculation equation of crack propagation length is derived.Combined with mass conservation equation, Langmuir equation and Darcy's law, the seepage equation of gas-bearing coal body was established, and considering the dynamic change of porosity and permeability, the fluid-solid coupling model of gas extraction by borehole was constructed.According to the above theoretical model and using COMSOLMultiphysics software, the antireflection effect of hydraulic punching holes in Naodong Coal Mine is simulated, and the hydraulic punching capacity of 1 t / m, 6 holes per row, and the spacing of 8.48 m are obtained.In order to evaluate the field application effect of the hole layout scheme, a hydraulic punching laboratory simulation system was developed based on the response of DC method. The effects of load, water and fracture on apparent resistivity of coal and rock mass were analyzed through laboratory experiments.The change law of apparent resistivity of coal and rock mass during punching is revealed.The average change coefficient of apparent resistivity (I) is used as the evaluation index of gas extraction effect of hydraulic punching hole, and the grading standard for evaluation of hydraulic punching effect is established.According to the above research results, the No. 17 coal seam of Naodong Coal Mine was punched on the spot, and the effect of punching area was evaluated by using direct current method.The results show that the effective influence ranges of hydraulic punching are as follows: the depth is -25m ~ 45m, the strike direction is 35m ~ 75m, and the strike radius is about 20m.The average coefficient of change of apparent resistivity in the test area is I _ (93), and the evaluation grade of hydraulic measures is grade 鈪，

本文編號(hào)：1736018