为了提高煤矿井下硬地层的钻进效率,借鉴石油钻头的设计和加工理念,提出了一种适用于煤矿井下硬岩钻进的新型弧角型PDC钻头的设计思路.采用有限元数值模拟方法,分别对直径为113 mm的弧角型聚晶金刚石复合片(PDC)钻头的切削结构和水力结构进行优化设计,得出:当采用内锥角为130°、外锥圆弧半径为20 m m的冠部形状,切削齿切削角度为-15°、侧转角为4°~6°,刀翼采用直刀翼的钻头切削结构时,破岩效果最佳;喷嘴喷射角为22°~30°、方位角的设计靠近切削齿的工作面时的钻头水力结构,能够满足岩屑的有效运移.基于此,试制了直径为113 mm的弧角型PDC钻头,并进行现场试验,结果表明:弧角型PDC钻头的平均寿命为626 m,平均钻进时效为25 m/h,与工区现用普通内凹型钻头相比,寿命提高了4倍,钻进效率提高了1倍,说明本文设计的弧角型PDC钻头能够代替普通内凹钻头应用于硬地层钻进,可同时达到提高钻进效率和降低施工成本的目的.%In order to improve the efficiency of hard formation drilling of coal mine ,a design concept of new arc angle Polycrystalline Diamond Compact (PDC) drill bit is put forward by referring the design and processing concept of oil PDC bit .Taking Ф113 mm arc angle PDC drill bit for example ,the cutting structure and hydraulic structure of the PDC drill bit are designed using Finite Element Method (FEM) .Simulation results show that ,when the crown shape with inner cone angle 130° and outer taper arc radius 20 mm ,the cutters with cutting angle -15° and inside angle 4°~ 6° ,and using straight blade ,the rock breaking efficiency of arc angle PDC drill bit is the best .In the same time , when the nozzle spray angle 22°~ 30° ,and the azimuth angle working face near the cutter ,the migration of cutting is the best .Based on the above research ,Ф113 mm arc angle PDC drill bit was produced .Field test show s that ,the average bit life and drilling efficiency of the drill bit are 626 m and 25 m/h ,respectively ,w hich are increased by 4 times and one times compared with the ordinary concave PDC drill bit .T herefore ,in the hard formation drilling process ,the arc angle PDC drill bit can be used to improve drilling efficiency and reduce drilling cost .
展开▼
