易坍塌地层双管水平定向钻进工艺研究

Dual rod horizontal directional drilling technology in collapsible formation

水平定向钻进技术已被广泛地用于铺设各种管线,具有施工速度快,对地面破坏小,不会影响已有管线的正常使用等优点。但是,在砂卵石和粉细砂类易坍塌地层中,常规的单钻杆水平定向钻进常会出现导向偏差和钻孔坍塌等事故。在已有技术的基础上,开发出了一套双管水平定向钻进系统,包括双回转动力头钻机、内外钻杆、双管导向节。通过现场应用证明了该双管系统具有导向精度高、调整方向灵敏等优点,能克服易坍塌地层带来的导向精度差和钻孔坍塌等难题。

The horizontal directional drilling(HDD)technology has been widely used for laying various pipelines,and has the advantages of high construction speed,small damage to the ground,and no interference to the use of the existing pipelines.However,in collapsible formation such as sand pebbles and fine sand,conventional single-tube HDD technology often encounters accidents such as guiding deviation and borehole collapse.Based on the existing technology,a dual rod horizontal directional drilling system has been developed,including the double-rotary drilling rig,the inner and outer drill rods,and the dual rod guiding section.The field application proves that the dual rod system has the advantages of high guiding precision and sensitive adjustment direction,and can overcome the problems of poor guiding precision and borehole collapse caused by collapsible formation.