超深井径向钻孔钛合金管转向阻力计算及安全评估

Steering resistance calculation and safety evaluation of titanium alloy pipe in radial drilling of ultra-deep well

为了解决塔河油田6000 m及以上深井径向钻孔作业时管柱强度低、无法很好地传递钻压等问题,提出利用修井机和油管、钛合金管进行径向钻孔工艺,并通过数值模拟的方法优选有矫直段的单向弯曲转向轨道,研究轨道转向半径、钛合金管外径及壁厚、轨道与管柱间隙对钻进能力的影响,其次,通过正交试验方法,对上述参数进行敏感度分析并进行参数优选。结果表明:轨道转向半径及间隙与转向阻力呈反比关系,而钛合金管外径以及壁厚与其呈正比。因此,推荐钛合金管与转向器轨道的组合参数为:轨道转向半径为600 mm,转向角度为30°,钛合金管外径为25 mm,壁厚为2 mm,钛合金管与转向器轨道的间隙为4 mm。

In order to solve the problems of low strength of the pipe string and inability to transmit the weight on bit during the radial drilling operation in deep wells of 6000 m and above in Tahe Oilfield,a radial drilling technology using workover rigs,oil pipes and titanium alloy pipes was proposed.The unidirectional curved steering track with straightening section was optimized through numerical simulation,and the influence of track steering radius,outer diameter and wall thickness of titanium alloy pipe,clearance between track and pipe string on the drilling capacity was studied.Through the orthogonal experiment method,the sensitivity analysis on the above parameters and the parameter optimization were conducted.The results showed that the track steering radius and the clearance were inversely proportional to the steering resistance,while the outer diameter and wall thickness of the titanium alloy pipe were positively proportional to the steering resistance.The combined parameters of the titanium alloy pipe and steering gear track were recommended as follows:the track steering radius was 600 mm,the steering angle was 30°,the outer diameter of the titanium alloy pipe was 25 mm,the wall thickness was 2 mm,and the clearance between the titanium alloy pipe and steering gear track was 4 mm.