煤矿井下泥岩地层定向钻孔套铣打捞技术

为解决煤矿井下定向钻孔在泥岩地层发生卡钻事故后采用套铣打捞存在套铣钻具回转阻力大、钻孔存在缩径或坍塌,易出现二次卡钻风险的问题,通过分析泥岩地层套铣打捞技术难点,借鉴石油和地质行业泥岩地层钻井或钻探施工技术,提出了套铣打捞过程中的短扫孔技术,每间隔15 m左右进行1次短扫孔,同时,在短扫孔基础上,提出了全孔套铣扩孔技术和局部偏心套铣扩孔技术。应用该技术,成功解决了新安煤矿孔深465 m,其中345~450 m均为泥岩的顶板高位钻孔卡钻事故。

Casing milling and fishing technology of directional borehole in mudstone formation in underground coal mine

In order to solve the problem that casing milling and fishing technology is used to salvage directional borehole in coal mine after the occurrence of stuck drilling accident in mudstone stratum, the hole with large rotary resistance of casing milling drilling pipe and hole shrinkage or collapse, even cause the risk of secondary stuck drilling, through analyzing the difficulties of milling and fishing technique in mudstone formation, learn from oil and geology industry mudstone formation drilling construction technology, the technique of short hole sweeping is proposed, and the interval is about 15 m. At the same time, based on the short hole sweeping, the milling and reaming techniques of all-hole sleeve and partial eccentric sleeve are proposed. With these techniques, the accident of stuck in the top plate of Xin’an Coal Mine with the hole depth of 465 m was solved successfully, and of which 345 m to 450 m are mudstone, this depth created the hole depth record of successfully milling and fishing the rock hole.