单弯螺杆钻具组合防斜打快技术研究

Application of Deviation Control and Drilling Fast Technology of Single Bending Screw Rod Assembly

针对易斜地区防斜打快问题,分析了单弯螺杆钻具组合的特点,并采用有限元分析方法对正常钻进时单弯螺杆钻具的力学特性进行了模拟。研究发现,钻头侧向力随转动按简谐规律变化,且弯角靠下井壁时钻头侧向力最大;钻头倾角呈正负交替的规律变化,因而在井斜角较大时具有较强的纠斜能力。有限元计算结果表明,改进的单弯螺杆钻具组合不会改变其在井下的应力状态,可以安全使用。

Aiming at the problems of deviation control and fast drilling in easy deviation areas,the mechanism of single bending screw rod is discussed in the paper.By using the finite element method,the mechanical model of Bottom Hole Assembly(BHA) is established and calculated.The results show that the stress of stabilizer is in the state of maximum value and bit lateral forces is maximum when the bending angle moves downwards,which the lateral force and dip angle of bit changing with the harmonic and alternate law.The research can provide the theoretical basis for BHA optimization and the design of working parameters.