摘要
针对水平井钻井因岩屑床导致托压、底部钻具组合黏托甚至卡钻等问题,基于风琴管谐振-脉冲生成、射流泵-负压抽汲和高压水射流等理论,设计了新型脉冲内磨钻头。该钻头可通过脉冲射流辅助破岩、反向射流负压抽汲及内磨削结构减小钻屑粒径,实现高效破岩与清除岩屑床。以内磨高压作用力、最小内磨末速度和最小加速管长度为特征参数建立了计算模型,以钻井液为高速流体,通过算例分析得到砂岩和泥岩的最小内磨末速度分别为64.65和67.08 m/s,最小加速管长度分别为158.45和165.37 mm。参数研究结果表明:最小内磨末速度随着能量系数和机械钻速的增加而增大,随内磨终止粒径的增大而减小,特别是当机械钻速小于3.048 m/h、内磨终止粒径小于0.3 mm时,其影响比较明显。所得结论为该型钻头的应用和优化提供了参考,也为清除水平井岩屑床提供了一种解决方案。
To address the issue ol weight stacking, BHA stick and even pipe sticking caused by the cutting bed in the horizontal well, based on the theories ol the organ pipe resonance-pulse generation, jet pump-vacuum swabbing and the high pressure water jet, a new type ol pulse mill bit has been designed. The bit can reduce the cutting particle size by means ol pulsed jet assisted rock breaking, jet backward vacuum swabbing and communica-tion chamber, leading to high efficiency rock breaking and removal ol cutting bed. Taking the high level impact stress, minimum cutting’s impact velocity and the minimum length ol accelerating tube as characteristic parameters, calculation model has been established. Using the drilling fluid as the high velocity fluid, example analysis has at-tained the sandstone and mudstone minimum cutting,s impact velocity, 64. 65 and 67. 08 m/s , respectively, and the minimum length ol accelerating tube ol 158.45 and 165.37 mm, respectively. The parameter study results show that the minimum cutting’s impact velocity increases with the increase ol the energy coellicient and the ROP, and decreases with the linal particle size ol the cuttings. Especially when the ROP is less than 3. 048 m/h and the linal particle size ol the cuttings is less than 0. 3 mm, the influence is obvious. The conclusion could provide reler- ences lor the application and optimization ol the drill bit, and also provide a solution lor removing the horizontal well cutting bed.
作者
魏征
高德利
刘永升
张璀
Wei Zheng Gao Deli Liu Yongsheng Zhang Cui(MOE Key Laboratory of Petroleum, Engineering, China University of Petroleum （ Beijing)
出处
《石油机械》
2017年第5期18-22,共5页
China Petroleum Machinery
基金
国家自然科学基金创新研究群体项目"复杂油气井钻井与完井基础研究"(51521063)
国家重点研发计划项目"钻井工艺及井筒工作液关键技术研究"(2016YFC03303)
关键词
水平井
脉冲内磨钻头
内磨高压作用力
最小内磨末速度
最小加速管长度
horizontal well
pulse mill bit
high-level impact stress
minimum cutting’s impact velocity
minimum length ol accelerating tube
