集中载荷作用下的套管抗挤能力分析

Analysis of anti-collapse ability of casing under the action of concentrated load

根据油田套管损坏情况,建立了集中载荷作用下的套管抗挤能力计算模型,利用能量法和曲杆理论,分析研究了承受180°对称分布集中载荷、90°均匀分布集中载荷和120°均匀分布集中载荷下中厚壁套管抗挤能力,得出了理想圆管抗挤强度和套管屈曲临界挤毁压力的计算公式,通过分析比较理论解与有限元解,其最大相对误差不超过1%,得出了套管抵抗局部载荷的能力低于抵抗均布载荷的结论。

The calculation model of anti-collapse ability of casing under the action of concentrated load is established.By means of energy method and curved bar theory,the anti-collapse abilities of the casing with medium and thick walls are analyzed and studied respectively under the actions of 180?symmetrically-distributed concentrated load,90?evenly-distributed concentrated load and 120?evenly-distributed concentrated load.The calculation formulas of ideal collapse strength and buckle critical pressure(Pcr)of the casing are obtained.By Comparison,the maximum relative error between the theoretical solution and the ANSYS solution is not more than 1%.Thus it comes to the conclusion that the ability of resisting the partial load for the casing is lower than that of resisting evenly-distributed load.