内压对射孔套管强度影响的有限元分析

Finite element analysis of the effect of internal pressure on perforated casing strength

射孔对套管抗挤强度的影响程度取决于多种因素。主要研究内压对射孔套管强度的影响。建立未射孔套管、不带水泥环射孔套管、外裹水泥环射孔套管有限元模型,并应用ANSYS有限元软件分析计算了未射孔、射孔及孔边开裂三种情况下套管的最大应力,同时研究了水泥环对射孔套管强度的影响。结果表明:射孔套管最大应力比未射孔套管增大了64%,孔边开裂进一步增大了射孔套管最大应力;固井水泥环可降低套管最大应力,提高射孔套管抗挤强度。

Several parameters determine the impact of perforating operation on casing collapse strength.The effect of internal pressure on perforated casing strength is the main research of this paper.The finite element analysis model for blank casing,perforated casing with/without cement sheath is established.The maximum stress can be calculated in the event of un-perforated casing,perforated casing and perforated casing with flaw by using the finite element analysis software and the influences of cement cylindrical on the perforated casing is also studied in the paper.The results indicate that the maximum stress of perforated casing magnifies 64% than un-perforated casing and the flaws around the hole improves on it;cement cylindrical is useful to lessen the maximum stress of casing and enhance the casing collapse strength.