川渝地区三维水平井钻柱力学模型研究

RESEARCH ON DRILL STRING MECHANICAL MODEL OF 3D HORIZONTAL WELL IN CHUAN-YU AREA

近年来川渝地区的水平井多设计为三维水平井,特别是页岩气井多设计为丛式三维水平井井组。三维水平井大幅度扭方位后均不同程度的出现摩阻、扭矩增大、钻具偏磨、定向托压等严重现象,严重影响了钻井安全和钻井速度。为此,在调研分析国外钻柱力学试验数据的基础上,研究三维水平井整体钻柱三维力学模型,结合有限元理论对钻柱受力力学分析方法,考虑井眼几何形状、钻柱屈曲、钻柱刚性对钻柱力学的影响,提出了三维空间中的整体钻柱与井壁接触力、摩擦力分布的计算方法,采用微软net平台c#语言编制了相应的计算机软件,使现场施工人员能够根据钻柱力学仿真数据及时了解井下钻柱形态与受力状态,及时调整施工参数,避免井下复杂情况的产生。

The most of horizontal wells were designed 3D horizontal wells in Sichuan- Chongqing region in recent years,especially shale gas wells were designed three- dimensional cluster horizontal wells group. In 3D directional well,the phenomenon of increscent frictional drag and torque,drilling tool wear etc. caused by varying the drill spring azimuth affected severely the drilling safety and drilling speed. So,based on researching overseas drill string mechanics data,the drill string mechanical model of 3D horizontal well was studied. Combining FEA theory of drill string force mechanical analysis,considering the influence of hole geometry shape,buckling and drill pipe rigidity on drill string mechanical property,the calculation methods of wall contact force and friction force of drill string were proposed,and the corresponding software was programmed by using c # language. Based on the simulation data of drill string mechanics,the downhole drill pipe form and force were knew in time to adjust operation parameter,avoid downhole complex.