低透煤层井下长钻孔水力压裂增透技术
发布时间：2019-05-11 02:26
【摘要】：针对我国低透气性煤层普遍存在瓦斯抽采效果差的现状,提出了利用大直径长钻孔水力压裂对煤层进行增透的技术措施,探讨了长钻孔水力压裂增透机理,并进行了煤矿井下煤层水力压裂瓦斯抽采试验。在成功施工顺层长钻孔的基础上,研发了一套适合井下水力压裂施工的快速封孔工具组合,分析了压裂过程中参数变化规律,提出了水力压裂影响范围、压裂效果和瓦斯抽采效果评价方法,并进行了考察和评价。研究表明:该技术克服了传统井下水力压裂存在的封孔质量差、压裂影响范围小等问题,压裂后煤层透气性系数提高了2.67倍,压裂最大影响半径达到了58 m,压裂后连续抽采130 d累计抽采纯瓦斯量为31.39万m~3,日最高抽采量2 668 m~3,瓦斯体积分数平均70.05%,百米钻孔瓦斯抽采纯量达到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，
本文编号：2474178
[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，
本文编号：2474178
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