裸眼完井螺旋钻孔-射孔套管的有限元分析

FEM for a type drilling-perforating casing with screw holding in open hole completion

针对裸眼完井中一种新型的螺旋钻孔-射孔套管,结合室内材料试验及有限元法,对不同深度的直井和水平井中套管承受非均匀载荷的力学性能进行分析。结果表明:随井深增加,套管所受应力和最大变形增加;同井深情况下,随着套管孔眼数量和孔眼面积增加,套管最大变形增加,最小应力减小、最大应力增加。应力集中是降低套管承载力的主要因素,选用套管时要考虑到载荷不均匀系数引起的应力破坏和变形引起的失稳破坏。研究结论可为合理选择、设计套管,确定套管钻孔和射孔的孔径、密度、相位,分析钻孔后套管的剩余强度,保证套管使用的安全性提供一定的理论依据。

In view of a new type drilling-perforating casing with screw holding in open hole completion, mechanical property problem of the casing which located at the different depth of straight well and horizontal well and bearing no-even load was studied with indoor material testing and finit-element analysis methods. The result indicated that the stress and the maximal distortion increased along with the increasing of the depth; under the same depth, the maximal distortion increased, the minimum stress decreased, and the maximal stress increased along with increasing of the eyelet quantity and eyelet area; the stress concentration is the major factor to depress the bearing capacity of the casing; the stress rupture resulted by load nonuniformity coefficient and the buckling collapse resulted by distortion should be considered when selecting casing. The research conclusion can provide theory basis for reasonable choice and design of the casing, the determination of aperture, density and phase of the drilling-perforating hole, analysis of casing retained strength after drilling and assurance of use security of the casing.