超短高能涡轮钻具研制及应用

Development and application of an ultra short high energy turbodrill

摘要:

针对超深层强研磨、高硬度地层机械钻速慢的问题，研制了一种超短高能涡轮钻具，并对其进行了参数校核和现场应用。该涡轮钻具创新设计了多曲面3D转子叶片，基于流体力学CFX软件，优化了转子叶片空间形态布局，使叶片的水力能量转化效率提高45%，扭矩增加了43.55%；通过将装有叶片的动力端和装有止推轴承的轴承端合二为一，使分体式的涡轮芯轴改进为一体式结构，长度由进口涡轮钻具的15 m缩短至8.3 m，大幅提高了涡轮钻具的可下入性和安全性，缩短了划眼和通井作业时间；最后采用有限元仿真对涡轮钻具产生的扭矩和丝扣连接强度进行了校核测试。该涡轮钻具先后在博孜、元坝等区块石英砂岩、火成岩、砾石层地层的48口井中成功应用，应用混合钻头后机械钻速平均提高100%，为我国深层超深层钻井提供了有力保障。

Abstract:

In order to solve the problems of strong abrasiveness and slow ROP in drilling ultra deep formation, an ultra short high energy turbodrill was developed and field-tested. A multi curved 3D rotor blade was innovatively designed for the turbodrill. Based on the fluid dynamics software CFX, the spatial configuration layout of the rotor blade was optimized to increase the hydraulic energy conversion efficiency of the blade by 45%, and the torque by 43.55%. With integration of the power end with the thrust bearing, the split turbine mandrel was modified into a one-piece structure with the length of the rotor blade cut short to 8.3m from 15m of the imported one; thus greatly improving passage and safety of the turbodrill, and reducing reaming and gauging time. The torque and thread connection strength of the turbodrill were calibrated by the linear element simulation. The turbodrill has been successfully applied in 48 wells in quartz sandstone, igneous rock and gravel formation in Bozi and Yuanba blocks with an average increase of 100% in ROP, which provides a strong support for deep and ultra deep drilling in China.