PDC钻头旋转齿技术在南海东部西江区块深部地层应用

南海东部西江区块深层古近系地层因地层可钻性较差、机械钻速(ROP)偏低、单只钻头进尺短，造成钻井周期长、作业成本高、井眼浸泡时间长、钻具遇阻和卡钻等复杂情况。为提高深部地层钻井作业效率，此文分析了西江区块地层特点以及常规PDC钻头在深部地层作业的缺陷，针对性地提出PDC钻头旋转齿钻头技术，该项技术很好地解决了机械钻速低和单只钻头进尺短的难题，在西江区块探井中应用，取得了显著的效果。井段平均ROP较邻井同井段提高31.46%，一趟钻完成进尺为1 421.0 m的作业井段，行程钻速为8.91 m/hr，整体行程钻速相比邻井平均水平提高89.57%，有效提高了古近系地层钻井效率，在该区块具有良好的推广价值。

Application of the Technique of a PDC Bit with Rotary Cutters in Deep Formations of the Xijiang Block in the Eastern South China Sea

The poor drilling ability formation of the Xijiang block in the Eastern South China Sea,low rate of ROP,and the short footage for single bit,bring risks such as long drilling circle,high operation costs,long borehole immersion time,drill blocking and sticking.To improve the efficiency of deep stratum drilling operation,this paper analyzes the formation characteristics and the defects of the traditional PDC bit in deep formation.Furthermore,rotary cutter bit technology,which is put forward to solve the problems of low mechanical drilling speed and short drill footage and is therefore applied in Xijiang block exploratory well,has achieved significant results.The average ROP of the well section is 31.46%higher than that of the same well section of the adjacent well,and a drilling operation completed the well section with a footage of 1421.0 m.The rate of roundtrip is 8.91 m/hr,and the whole trip drilling rate increases by 89.57%compared with the average level of adjacent wells.The drilling efficiency of the paleogene strata is effectively improved,which has great promotion value in this block.