复合锥单牙轮钻头牙齿磨损研究

Study on tooth wear of compound cone single cone bit

摘要:

复合锥单牙轮钻头是基于球形单牙轮钻头的新型单牙轮钻头，其独特破岩方式能提高钻头效率。但现场试验发现，钻头牙轮小端一侧切削齿和保径齿磨损严重，牙轮大端切削齿和保径齿基本没有磨损，导致整个钻头钻进速度降低。为弄清偏磨机理，通过有限元分析方法对钻头各齿圈牙齿载荷变化规律进行了分析，并分析了各齿圈牙齿的切削轨迹形状和牙齿与岩石的接触时间。结果表明：牙轮大端的牙齿载荷大于牙轮小端的牙齿载荷，但牙轮小端牙齿与岩石的接触时间更长。综合分析牙齿破岩时间和牙齿轴向载荷，理论上⑥号齿圈牙齿磨损应该最小。现场试验结果表明：不但⑥号齿圈磨损较小，①、④、⑤号齿圈的磨损更小；钻头一侧保径齿磨损严重，且⑦、⑧号齿圈磨损严重，根据研究结果分析认为钻头钻进过程中向井壁一侧发生倾斜，导致钻头一侧切削齿和保径齿磨损严重。

关键词:单牙轮钻头;复合锥;牙齿磨损;牙齿载荷;轨迹长度

Abstract:

Compound cone single cone bit is a new type of single cone bit based on spherical single cone bit. Its unique rock breaking method can improve the bit efficiency. The field test found that the cutting teeth and diameter retaining teeth on the small end of the drill bit tooth wheel were seriously worn， and the cutting teeth and diameter retaining teeth at the large end of the tooth wheel were basically not worn， resulting in a decrease in the drilling speed of the entire drill bit. In order to find out the reasons for the uneven wear of the drill bit， the tooth load of each ring gear of the drill bit was tested by finite element analysis method， and the cutting trajectory shape of each ring gear tooth and the contact time between the tooth and the rock were analyzed. The results showed that the tooth load at the large end of the tooth wheel was greater than that at the small end of the tooth wheel， but the contact time between the teeth at the small end of the wheel and the rock was longer. Based on the analysis of tooth rock breaking time and tooth axial load， the wear of No.⑥ ring gear teeth should theoretically be minimal. The field test results show that not only the wear of the No.6 ring gear is small， but also the wear of the No.①，④ and ⑤ ring gear is smaller. The diameter retaining teeth on the side of the drill bit are seriously worn， and the wear of the ring gear No.⑦ and ⑧ is serious， it can be determined that the drill bit is tilted to the side of the well wall during drilling， resulting in serious wear of the cutting teeth and diameter retaining teeth on the side of the drill bit.

Key words:single cone bit;compound cone;tooth wear;tooth loading;track length