【摘要】：針對(duì)我國(guó)低透氣性煤層普遍存在瓦斯抽采效果差的現(xiàn)狀,提出了利用大直徑長(zhǎng)鉆孔水力壓裂對(duì)煤層進(jìn)行增透的技術(shù)措施,探討了長(zhǎng)鉆孔水力壓裂增透機(jī)理,并進(jìn)行了煤礦井下煤層水力壓裂瓦斯抽采試驗(yàn)。在成功施工順層長(zhǎng)鉆孔的基礎(chǔ)上,研發(fā)了一套適合井下水力壓裂施工的快速封孔工具組合,分析了壓裂過程中參數(shù)變化規(guī)律,提出了水力壓裂影響范圍、壓裂效果和瓦斯抽采效果評(píng)價(jià)方法,并進(jìn)行了考察和評(píng)價(jià)。研究表明:該技術(shù)克服了傳統(tǒng)井下水力壓裂存在的封孔質(zhì)量差、壓裂影響范圍小等問題,壓裂后煤層透氣性系數(shù)提高了2.67倍,壓裂最大影響半徑達(dá)到了58 m,壓裂后連續(xù)抽采130 d累計(jì)抽采純瓦斯量為31.39萬(wàn)m~3,日最高抽采量2 668 m~3,瓦斯體積分?jǐn)?shù)平均70.05%,百米鉆孔瓦斯抽采純量達(dá)到0.55 m~3/min。
[Abstract]:In view of the poor effect of gas extraction in low permeability coal seam in China, this paper puts forward the technical measures of using large diameter and long hole hydraulic fracturing to increase the permeability of coal seam, and probes into the mechanism of long hole hydraulic fracturing. The hydraulic fracturing gas extraction test of coal seam in coal mine is carried out. On the basis of successful construction of bedding long drilling, a set of rapid sealing tools suitable for downhole hydraulic fracturing construction is developed, the variation law of parameters in fracturing process is analyzed, and the influence range of hydraulic fracturing is put forward. The evaluation methods of fracturing effect and gas extraction effect are investigated and evaluated. The research shows that the technology overcomes the problems of poor sealing quality and small influence range of fracturing existing in traditional downhole hydraulic fracturing. After fracturing, the permeability coefficient of coal seam increases by 2.67 times, and the maximum impact radius of fracturing reaches 58m. After fracturing, the cumulative amount of pure gas extraction is 313900 m 鈮，

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