牙轮钻头损坏分析及应对措施

大庆油田徐家围子地区深部地层岩石可钻性差、研磨性强、硬度高，在纵向上砂泥岩互层且存在砾石层，钻井难度大，严重地影响钻头和钻具使用寿命；统计分析表明，该地区牙轮钻头损坏的主要表现为齿磨、掉齿、断齿、牙轮卡死和外径磨损等。据此提出了一系列应对措施：大力改进了硬质合金齿材料，开发新齿形的硬质合金齿；采用复合齿与稀土齿混装以增加抗研磨和冲击能力；改进相应配套钻井措施等。

ANALYTIC STUDY ON DAMAGE MECHANISM OF ROCK BITS AND CORRESPONDING MEASURES SUGGESTED

The deep formations at Xujiaweizi area in the Daqing oil field present the features of poor drillability, high abrasiveness and high hardness, vertically inter layered sandstones and mudstones, and gravel formations exisited. All these features lead to difficult drilling and thus shorten the life expectancy of drill bits and drilling tools. The statistical analysis indicates that the damage to cone bits used in this area includes worn teeth, bit teeth dropping, broken teeth, bit cone sticking, and gauging wearing. This paper recommends a series of measures, such as improving the carbide insert material, developing carbide insert with novel shape, combining compound teeth with lanthanum teeth, and improving drilling program are recommended. All those countermeasures have facilitated the wide application of high efficiency bits.