基于ANSYS的水平井下套管摩阻分析计算

Calculation of frictional drag of casing running in horizontal well based on ANSYS

付建红 龚龙祥 胡顺渠 罗飞 马立 尚立

FU Jian-hong GONG Long-xiang HU Shun-qu LUO Fei MA Li SHANG Li

西南石油大学油气田地质与开发工程国家重点实验室, 四川成都 610500 中石化西南油气分公司工程技术研究院, 四川德阳 618001

随着水平井和大位移井的日益普遍,由于套管柱自重和井眼弯曲等多种因素的影响,水平井和大位移井中的套管柱存在较高的摩阻力,摩阻过大将会影响到套管柱的顺利下入,水平井中套管柱轴向力的准确预测也为套管强度设计提供了重要的基础数据。用CAE大型有限元软件ANSYS,对江沙8-H水平井的?139.7 mm套管的受力和变形进行了数值模拟,计算了刚性扶正器处的接触力和刚性扶正器间套管的横向位移,并得到了套管柱在水平井中的摩阻力。计算模型考虑了套管的刚度和刚性扶正器对摩阻力影响,计算结果与现场实测数据比较吻合。计算结果表明,水平井中套管摩阻对轴向力的影响较大,且刚性扶正器间套管较长时,扶正器间大部分套管仍会与井壁接触,导致扶正效果降低。该计算方法为钻井工程设计提供了理论支持。

Due to the effect of such factors as casing string weight and wellbore bending,casing strings have more great frictional drag along with the development of horizontal wells and extended reach wells.The frictional drag is too great that greatly affects favorable running casing.Precise predicting axial force of casing strings in the horizontal well provides important basic data for casing strength design.With the finite element analytic software ANSYS of CAE,the author in this paper simulates ?139.7 mm casing load and deformation of Jiangsha-8 horizontal well,calculates contact force of stiff centralizers and casing transversal displacement between stiff centralizers,and obtains the frictional drag of casing strings in the horizontal well.The calculated model takes casing stiffness and the affect of stiff centralizers acting on the frictional drag into account.The calculated result is fit to the measured data,which indicates that the affect of casing frictional drag acting on axial force is great.Most of the casing between centralizers will contact with borehole walls when the casing between centralizers is too long,decreasing the effect of centralizing.The new calculation method provides theoretical support for drilling engineering design.

10.3969/j.issn.1000-7393.2007.04.009