井底岩屑磨料脉冲射流钻井技术磨损实验研究

EXPERIMENTAL STUDY ON ABRASION OF BOTTOM-HOLE CUTTINGS ABRASIVE IN PULSE JET DRILLING

采用自行研制的井底岩屑磨料脉冲射流工具及模拟井筒实验装置,通过磨料脉冲射流破岩实验,研究了磨料介质(岩屑、石英砂及钢珠)、自激振荡腔内碰撞壁以及喷嘴的磨损情况。结果表明,岩屑磨料在对岩石冲击磨削的同时,其自身强度也在衰减;石英砂的尖锐棱角被磨平,颗粒变得圆滑;钢珠质量在破岩实验的0～60min内减少比较明显,在60min之后减少的幅度降低,同时,其外表面和球度也发生改变,但未见明显的裂缝等微观特征;冲蚀严重的位置位于井底岩屑磨料脉冲射流调制工具自激振荡腔内的碰撞壁、喷嘴以及流道等处。

The experiments of rock breaking with abrasive pulse jet tool were conducted by using self developed bottom hole cuttings abrasive pulse jet tool and simulating well-bore device to study wear features of abrasive particle(including cuttings,quartz sands and steel balls),impinge wall in self-excited oscillation cavity and nozzles.The results showed that the strength of cuttings abrasive decayed while impacting and grinding rocks,the sharp corner of quartz sands were worn to be round,the mass of steel balls was reduced greatly between 0 and 60 minutes,and it would change a little after 60 minutes.At the same time,the surface and sphericity of steel balls also changed remarkably,wherever,no obvious microscope features yielded including fractures.The abrasion position of bottom-hole cuttings abrasive pulse jet tool lay on impinge wall of the self excited oscillation cavity,nozzles and flow channel.