磨损套管抗内压强度试验与有限元分析

当套管受到严重偏磨时,套管抗内压和抗外压能力显著下降。鉴于此,从理论和试验2个方面分别研究了磨损套管的抗内压强度,研究结果表明:(1)在内压作用下,磨损套管的周向应变发生局部变化,最大值主要发生在磨损与未磨损的过渡区,最小值集中在磨损最严重的区域,因此套管截面在磨损区域"内凹";(2)在相同内压力作用下,随着磨损量的增大,磨损最严重处先周向变形减小且内收缩,继而周向变形增大,与磨损区相对的另一侧,从向外鼓胀变形转而向内收缩,套管截面出现椭圆变形;(3)在套管内壁的磨损初期相对磨损量对套管的初始抗内压性能影响相对较大。

Experiment and Finite Element Analysis of the Internal Pressure Strength of Worn Casing

When casing suffers serious eccentric wear,its capacity of internal and external pressure resistance drops remarkably.Therefore,research on the internal pressure strength of worn casing was conducted both in theory and experiment.The following conclusions have been reached.First,due to the effect of internal pressure,the circumferential strain of worn casing changes locally.The maximum value mainly occurs in the transition zone between worn and non-wear regions;the minimum value concentrates on the most serious worn zone.Therefore,the casing cross-section is characterized by "inner concave" in the worn zone.Second,due to the effect of phase pressure,with the increase of abrasion,the most serious worn part first deforms circumferentially and shrinks internally,then increases in circumferential deformation.The other side opposite to the abrasion area first swells and deforms outwards,then shrinks inwards.The casing section is characterized by elliptic deformation.Third,the effect on the initial internal pressure performance at the first stage is relatively considerable.