壁厚不均缺陷对膨胀套管性能的影响

采用有限元法分析了壁厚不均缺陷对膨胀套管性能的影响。分析研究结果表明(1)壁厚不均的膨胀套管膨胀后壁厚不均度增大;(2)壁厚不均的膨胀套管膨胀后各部位壁厚均减小,最薄侧壁厚减薄量随壁厚不均度的增加呈上升趋势,而最厚侧壁厚减薄量随壁厚不均度的增加呈下降趋势;(3)壁厚不均度对膨胀套管自由端面轴向总位移影响很小;(4)膨胀套管壁厚不均度小于0.2时,所需最大膨胀力变化不大;壁厚不均度大于0.20时,所需最大膨胀力迅速降低;(5)壁厚不均度对膨胀套管膨胀后的残余应力影响很小。

Influence of wall thickness nonuniformity on property of expandable casing

The influence of wall thickness nonuniformity on the property of the expandable casing is analyzed by the finite element analysis. The result shows that: (1) the degree of nonuniformity of the wall thickness becomes higher while the expandable casing is expanded; (2) the wall thickness of the casing becomes thinner roundly after it is expanded; (3) the nonuniformity of the wall thickness has little effect on the axial displacement of the free end surface of the casing; (4) when the nonuniformity degree is less than 0.2,the maximal expandingforce needed has slight variation; and it decreases rapidly when the nonuniformity degree is higher than 0.2; (5) the nonuniformity of the wall thickness has little influence on the residual stress of the expanded casing.