整体式卡瓦齿槽结构优化

Structure optimization of integral slip groove

为提高可溶桥塞中整体式卡瓦的承载能力,对卡瓦齿槽结构进行了优化。首先,开展整体式卡瓦承载能力实验并分析卡瓦失效的原因。然后,应用有限元法建立了整体式卡瓦及与之接触部件的六分之一模型和广义接触关系,分析了单一齿槽结构参数对卡瓦锚定效果的影响,并通过正交试验优选出最佳齿槽结构参数:前排齿槽轴心线距离卡瓦前端25 mm,前后排齿槽轴向间距为15 mm,齿槽轴心线夹角为20°,齿槽轴心线倾角为20°,齿槽深度为7 mm。最后,对齿槽结构优化后的整体式卡瓦进行实物加工并开展承载能力实验,结果表明该卡瓦的轴向承载力可达629 kN,能够承受内径为114.3 mm的套管在井下70 MPa压力环境中受到的轴向载荷。仿真和实验结果表明整体式卡瓦齿槽结构参数对卡瓦的承载能力有重要影响,研究结果对镶齿类整体式卡瓦结构设计具有重要参考价值。

To improve the bearing capacity of the integral slip in the soluble bridge plug, the structure of slip groove was optimized. Firstly, the failure reasons of the integral slip were analyzed through the bearing capacity test. Secondly, a one-sixth model and the generalized contact relation of integral slip and its contact parts were established by finite element method, and the influence of single tooth structure parameter on the anchoring effect of slip was analyzed. Then, an orthogonal experiment was designed to select the best groove structure parameters: the distance between the front groove axes and slip front was 25 mm, the distance between the front and back groove axes was 15 mm, the angle of groove axis was 20°, the inclination angle groove axis was 20° and the groove depth was 7 mm. Finally,the integral slip with optimized groove structure was processed and the bearing capacity experiment was carried out. The experiment results showed that the axial bearing capacity of slip reached 629 kN, which could bear the axial load of casing with inner diameter of 114.3 mm under the 70 MPa downhole pressure environment. The simulation and experimental results indicate that the integral slip groove parameters have significant influence on the bearing capacity of slip. The research results have important reference value for the design of integral slip structure with insert teeth.