镶齿型可溶桥塞卡瓦结构优化

Structural optimization of insert-type soluble bridge plug slips

可溶桥塞是油气开采过程中必备的井下工具,其卡瓦机构直接影响其锚定性能。本文结合可溶桥塞的工作特点和受力分析,应用显式动力学模拟桥塞锚定过程,分析了单一卡瓦结构参数对锚定性能的影响。分析结果表明:随着齿槽轴心线夹角和齿槽轴心线倾角的增加,卡瓦牙与套管间的接触压力和咬合深度逐渐减小,锚定效果逐渐减弱;齿槽深度、卡瓦牙间距和前端距对卡瓦的结构强度影响较大,通过破坏卡瓦本体的结构强度,进而影响锚定效果的稳定性。最后以最大接触应力和咬合深度极差值为评价指标,应用正交实验优选出最佳卡瓦结构参数组合:齿槽轴心线夹角11°,齿槽轴心线倾角70°,齿槽深度7.0 mm,卡瓦牙间距21 mm,前端距22 mm。

The soluble bridge plug is a necessary downhole tool in the process of oil and gas exploitation,and its slip mechanism directly affects its anchoring performance.Based on the working characteristics and force analysis of the soluble bridge plug,this paper uses explicit dynamics to simulate the bridge plug anchoring process,and analyzes the influence of the structural parameters of the single slip on the anchoring performance.The analysis results show that with the increase of the included angle and the inclination of the cogging axis,the contact pressure and the occlusal depth between the slip teeth and the casing gradually decrease,and the anchoring effect is gradually weakened.The depth of the tooth space,the distance between the teeth of the slip and the front-end distance has great influence on the structural strength of the slip.By destroying the structural strength of the slip body,the stability of the anchoring is affected.Taking the maximum contact stress and the occlusal depth range as the evaluation indicators,the optimal slip structure parameters are obtained by orthogonal experiment as follows:the included angle of the cogging axis is 11°,the inclination angle of the cogging axis is 70°,the depth of the tooth space is 7.0 mm,the distance between the teeth of the slip is 21 mm,and the front-end distance is 22 mm.