摘要
针对大直径反循环钻头底面形状对反循环形成效果的影响,分析了反循环钻头孔底循环介质流动的特点;基于反循环钻头孔底流动模拟实验器对凸面型、凹面型和凸凹组合型3种典型的钻头底面形状进行了对比测试;运用CFD技术对不同底面形状反循环钻头孔底局部流场进行了数值模拟,揭示了其各自的流动特征及影响反循环形成效果的机理。实验结果表明,凹面型钻头底面形状更有利于反循环的形成。反循环钻头底面形状设计研究对改善和提高大直径反循环钻头的性能具有重要的意义。
Aiming at the reasonable structure design of large-diameter reverse circulation drill bit used in gas drilling, research on the relationship between undersurface figure of reverse circulation drill bit and forming effect of reverse circulation was carried out in this paper. Firstly, the flow characteristics of compressed air under reverse circulation drill bit were analyzed. Then the experimental tests were done with experimental apparatus for hole-bottom flow field simulation of special reverse circulation drill bit, three types of undersurface figure： con- vexity, concave and combination of convexity and concave were designed for reverse circulation drill bit and tested with regard to forming effect of reverse circulation, the results show that concave undersurface figure is beneficial to formation of reverse circulation. Finally, with CFD technology, the numerical simulation of bottom flow field formed by reverse circulation drill bit with different undersurface figure was done, which exposes the flow characteristics of compressed air under the drill bit and the mechanism of reverse circulation forming affected by undersurface figure. The research on the undersurface figure design is helpful to improve the performance of large-diameter reverse circulation drill bit.
出处
《煤田地质与勘探》
CAS
CSCD
北大核心
2012年第3期82-85,共4页
Coal Geology & Exploration
关键词
反循环钻头
底面形状
实验测试
数值模拟
reverse circulation drill bit
undersurface figure
experimental test
numerical simulation
