利用井底应力场研究双级钻头导扩眼直径比

Research on diameter ratio of pilot to enlarger of two-stage bits using bottom-hole stress field

彭烨 沈忠厚

PENG Ye SHEN Zhong-hou

中国石油大学石油工程学院, 山东 东营 257062 胜利石油管理局钻井工艺研究院, 山东 东营 257017

College of Petroleum Engineering, China University of Petroleum, Dongying 257062, Shandong, China Drilling Technology Research Institute of Shengli Petroleum Administration Bureau, Dongying 257017, China

为研究双级钻头导扩眼直径比,应用双级钻头的井底应力场分析模型、开挖方法、分析过程及分析选项,对?190.5 mm×?311 mm、?215.9 mm×?311 mm和?241.3 mm×?311 mm 3种双级钻头进行井底三维应力场开挖分析,得到了井底应力场分布曲线,井底应力场曲线显示:?241.3 mm×?311 mm双级钻头的径向应力释放较充分,有利于提高机械钻速;?215.9 mm×?311 mm双级钻头径向和周向两应力差减小,但仍有较大提高机械钻速的潜力;?190.5 mm×?311 mm双级钻头的径向和周向两应力差很小,其提高机械钻速的潜力较小;双级钻头的导眼体与钻头的直径比存在最优值,最优直径比为0.7~0.8。

The excavation analysis of the bottom-hole three dimension stress field excavation is carried out on the two-stage bits of three diameter ratio ?190.5 mm×?311 mm,?215.9 mm×?311 mm,and ?241.3 mm×?311 mm in order to research the diameter ratio of pilot to enlarger.The analysis model,excavating methods,analyzing process,and analysis options of the bottom-hole stress field are applied during the research process.The distribution curve of the bottom-hole stress field is obtained,which shows that the radial stress of the ?241.3 mm×?311 mm bit is more completely released and is favorable for increasing the penetration speed.The difference between radial stress and circumferential stress of the ?215.9 mm×?311 mm bit gets smaller but it still has great potential to improve its penetration rate.The difference of radial stress and circumferential stress of the ?190.5 mm×?311 mm bit is small and the potential to increase penetration speed.Its optimum diameter ratio of pilot to enlarger is 0.7~0.8.

10.3969/j.issn.1000-7393.2007.01.007