套管抗挤强度的可靠性评价方法

套管抗挤强度是衡量套管强度性能的一项重要指标.采用置信度与可靠性设计相结合的高精度小子样方法,对阿科公司统计的套管（7in,29ppf,L80-13Cr）抗挤强度的48个试验数据进行了分析,并与阿科公司的分析方法进行了比较.初步验证了这种方法,计算结果稳定,计算精度高,可获得比API名义值较大的合理的数值结果,使套管抗挤强度性能得到更加充分的利用,并节省试样,为合理评价套管的抗挤强度提供了理论和方法,起到了优化管柱节约成本的作用.

Reliability Evaluation Method for Casing Strength of Collapse Resistance

The casing strength of collapse resistance is an important index of weighing the performance of casing strength. Small sample method of high precision that combines degree of confidence with reliability design is adopted to analyze 48 experimental data of casing (7in, 29ppf, L80-13Cr) strength of collapse resistance obtained from the statistics by the company of ARCO. Compared with the analytical method of ARCO, this method is verified that it can provide stable calculation results with high precision. Moreover, reasonable prediction values which are bigger than API nominal value can be obtained, which enables more sufficient use of casing strength of collapse resistance so as to save specimens. It provides theory and method for reasonable evaluation of casing strength of collapse resistance, and optimizes casing string, thus reducing the cost.