摘要
利用微型钻头模拟PDC钻头的切削破岩过程 ,对PDC钻头的岩石研磨性进行了试验研究。根据有关磨损理论 ,提出以PDC切削刃在单位正压力下经过单位摩擦路程的体积磨损量作为岩石的研磨性系数 ,建立了根据研磨性系数预测PDC切削齿磨损寿命的理论模型。用试验方法测定了泥板岩、砂质泥岩、泥质砂岩、砂岩、石灰岩、花岗岩等不同岩样的研磨性系数 ,其数值范围为 10 -6～ 10 -3 mm3 / (kN·m)。采用公比为 10的等比级数分级方法 ,将我国石油钻井地层的研磨性分成四级。对直径 2 16mm的PDC钻头的磨损分析表明 ,在研磨性系数小于 5× 10 -5mm3 / (kN·m)的低研磨性地层中 ,切削齿的磨损寿命可达 35 0h左右 ;而在研磨性系数大于 5× 10 -4mm3 / (kN·m)的高研磨性地层中 ,切削齿磨损寿命在 10h以下。
The rock abrasiveness encountered in drilling using PDC bit was discussed. The rock abrasiveness factors of typical lithology, such as argillite, sandy shale, shaly sand, sandstone, limestone and granite, were determined by cutting tests, in which micro PDC bits were used to simulate the rock bit interaction. The ratio of the volume worn away from PDC cutters to frictional works consumed during cutting rock was used as the rock abrasiveness index. The ratio values were in range 10 -6 mm 3/(kN·m) to 10 -3 mm 3/(kN·m). The drilled formations were divided into four classes, according to the abrasiveness indexes of formations. A mathematical model for predicting working life of PDC cutters based on the rock abrasiveness was derived. The laboratory and field test results demonstrated that the working life of PDC cutters in drilling the formation with abrasiveness index less than 5×10 -5 mm 3/(kN·m) is about 350 hours, and it is less than 10 hours when the abrasiveness index of formation is over 5×10 -4 mm 3/(kN·m).
出处
《石油大学学报（自然科学版）》
EI
CSCD
北大核心
2003年第2期41-43,共3页
Journal of the University of Petroleum,China(Edition of Natural Science)
