连续管钻井水力加压器结构设计

连续管钻井过程中,底部钻具组合无钻铤,钻压施加困难。为此,设计了一种适用于88.9 mm微小井眼连续管钻井的73 mm三级水力加压器,建立了水力加压器串联在涡轮钻具上方时产生的轴向推力计算模型。为了延长水力加压器的工作寿命,设计了密封性能优良的车氏密封结构;主活塞杆与主缸体之间采用矩形花键连接方式,并进行了矩形花键连接副的接触应力分析。计算与分析结果表明,在钻井液排量5.0～6.0 L/s、密度1.05～1.20 g/cm3条件下可产生50～90 kN的轴向推力,完全满足88.9 mm微小井眼连续管钻井需要。

Structural Design of the Hydraulic Thruster for Coiled Tubing Drilling

It is difficult to provide WOB because of no drill collar on BHA in the process of coiled tubing drilling.Therefore,a kind of 73 mm three-stage hydraulic thruster suitable for the 88.9 mm micro-hole coiled tubing drilling was designed.The calculation model for the axial thrust of the thruster series connection which is produced above turbo-drill was established.The Che's seal structure with excellent sealability was designed in order to lengthen the service life of the thruster.The rectangular spline was adopted as the connection mode between the main piston rod and the cylinder body.The contact stress analysis of the rectangular spline connection pair was conducted.The calculation and analysis show that the axial thrust of 50~90 kN will be produced when the drilling fluid displacement is 5.0~6.0 L/s and the density is 1.05~1.20 g/cm3,which completely satisfies the requirement of 88.9 mm micro-hole coiled tubing drilling.