筛管压溃强度计算公式及适用性

针对筛管受地层中围压作用压溃失效缺乏通用计算分析模型的问题，利用ABAQUS软件建立了考虑初始椭圆度影响的平行布孔筛管有限元模型，研究外压作用下筛管的压溃行为。通过与文献中的实验结果对比表明，该有限元模型可准确地预测筛管的压溃强度。基于不同几何特征、材料特性以及布孔参数等筛管压溃强度数值模拟结果，建立了筛管压溃强度的简化计算公式。利用该计算公式，计算不同几何尺寸和材料属性的筛管压溃强度，与实验结果相比平均误差为7.0%。为了便于工程应用，分析了利用DNV，API等标准规范确定该公式中筛管对应的布孔前套管的静水压溃强度的可行性。结果表明，所建立的防砂筛管压溃强度计算公式可为实际工程中防砂筛管的强度预测与参数优化提供理论支持。

Calculation formula of collapsing strength of screen casing and analysis of its applicability

Aiming at the lack of a universal computational and analysis model for the collapsing failure of screen casing under confining pressure in the formation, a finite element model of screen casing with parallel hole arrangement considering the influence of the initial imperfection was established using ABAQUS software to investigate the collapsing behavior of screen casing under external pressure. The comparison with experimental results in the literature shows that this finite element model can accurately predict the collapsing strength of screen casing. Based on the numerical simulation results of collapsing strength of screen casing such as different geometric features, material properties, and hole parameters, a simplified calculation formula was developed for the collapsing strength of screen casing. Using this formula, the collapsing strength of screen casings with various geometric sizes and material properties is calculated out, and the average error is 7.0% as compared with the experimental results. In order to facilitate the engineering application, the paper analyzes the feasibility of determining the collapse pressure of the intact pipe in the formula by use of the standard specifications such as DNV and API. The results show that the calculation formula for the collapsing strength of sand control screen can provide a theoretical support for the strength prediction and parameter optimization of sand control screen in practical engineering.