煤矿井下复杂岩层跟管定向钻进技术研究

Research on directional drilling technology for complex rock strata in coal mines

摘要:

为了解决煤矿井下复杂岩层破碎定向钻进出现孔壁坍塌而成孔难题，创新发明出复杂岩层跟管定向钻进技术护住复杂破碎孔段。该技术先采用中心定向钻具外跟套管穿过复杂地层，然后提出中心定向钻具利用外部套管护住复杂岩层孔段，最后在外部套管内下入下一级定向钻具施工。本文通过开展跟管定向钻具设计、跟管定向钻进工艺研究，并将该技术应用于淮北某矿高位定向钻孔试验。试验中该技术成功护住了由2层煤线、1层泥岩组成的103.5 m复杂岩层孔段，最终定向钻进成孔孔深530 m。试验表明，本技术可有效护住复杂地层孔段，提高复杂岩层定向钻孔深度和保护抽采通道。

Abstract:

In order to solve the difficulty in drilling holes in fractured complex rock strata due to wall collapse in underground directional drilling at coal mines， a casing while directional drilling technique for complex rock strata was invented to protect the hole section over complex fractured rock. First， the concentric directional drilling stem drills to pass through the complex strata with the outer casing； then， the concentric directional drilling stem is tripped out of the hole and the outer casing is left in place to protect the hole section over the complex strata， and finally， the directional drilling stem of smaller size is run through the outer casing to continue drilling. In this paper， the design of the casing while directional drilling tool and the research on the casing while directional drilling process are described. The technique was tested for drilling a high-position directional hole at a mine in Huaibei， where it successfully protected the 103.5m complex strata hole section composed of two layers of coal lines and one layer of mudstone with the completion depth of 530m. The test showed that this technology can effectively protect the complex strata hole section， and increase the directional drilling depth in complex strata and protect the extraction channel.