镶齿桥塞坐封对套管力学性能的影响试验研究

Experimental Study on the Influence of Insert Tooth Bridge Plug on The Mechanical Properties of Casing

针对卡瓦式桥塞坐封对套管的损伤问题,提出了一种镶齿桥塞,根据卡瓦坐封套管力学状态计算及有限元方法,分析了桥塞坐封后卡瓦牙与套管内壁之间的接触应力嵌入深度。结果表明:整个桥塞除卡瓦外其余部件的应力水平都比较低,上卡瓦牙高侧产生了很大应力,达到硬质合金可承载强度值;坐封后下卡瓦的第一排牙产生极大应力,下卡瓦牙周向均匀接触于套管内壁面,可有效坐封桥塞,且镶齿对套管表面应力影响较小;试验模拟坐封后镶齿卡瓦承压能力和坐封效果均较稳定。研究结果可为连续管钻水平井镶齿卡瓦桥塞的优化设计提供理论及试验依据。

In view of the damage of slip bridge plug setting to the casing,a kind of insert bridge plug was proposed.According to the mechanical state calculation and finite element method of slip setting casing,the contact stress embedding depth between the slip tooth and the inner wall of the casing after the bridge plug was analyzed.The results show that the stress level of the remaining parts of the whole bridge plug except the slip is relatively low,and the high side of the upper slip tooth generates a large stress,reaching the bearing strength value of cemented carbide.After setting,the first row of teeth of the lower slip generates large stress.The teeth of the lower slip contact the inner wall surface of the casing uniformly in the circumferential direction,which can effectively set the bridge plug,and the effect of the inserted teeth on the surface stress of the casing is small.The test simulation shows that the pressure-bearing capacity and setting effect of the inserted teeth slip after setting are relatively stable.The research results provide a theoretical and experimental basis for the optimization design of the inserted teeth slip bridge plug in the continuous pipe drilling horizontal well.