不同钢级油气管道剩余强度评价方法对比

Comparison of Residual Strength Evaluation Methods for Different Grades of Oil and Gas Pipelines

为了精确评价油气管道腐蚀安全情况,利用ASME B31G标准、修正的ASME B31G标准、DNV-RPF101规范、PCORRC规范和有限元分析法等5种评价方法对不同钢级油气管道剩余强度进行计算,并对比试验爆破压力,分析不同评价方法的保守性、准确性和集中性。结果表明:不管是在低钢级油气管道还是中高级油气管道,ASME B31G规范计算结果误差都很大,数据集中性差,不稳定;修正的B31G规范保守性比ASME B31G有所改善,但是误差仍然很大;DNV-RP-F101规范和PCORRC规范计算误差相对较好,数据集中性表现理想,尤其适合于X60以上中高级油气管道;非线性有限元分析方法计算结果误差小、集中性好、分布稳定、保守性低,对不同钢级油气管道都适用,在所有评价方法中表现最理想。

In order to accurately evaluate corrosion safety of oil and gas pipelines,five evaluation methods including ASME B31 G standard,revised ASME B31 G standard,DNV-RP-F101,PCORRC code and finite element analysis method,were used to calculate residual strength of different grade oil and gas pipelines,and the test blasting pressures were compared to analyze conservativeness,accuracy and concentration of different evaluation methods. Results showed that calculation errors of ASME B31 G code were very large,and data centralization was poor and unstable. The conservatism of revised B31 G code was better than that of ASME B31 G code,but errors were still large. However,the calculation errors of DNV-RP-F101 code and PCORRC method were relatively good. Data centralization was ideal,especially suitable for oil and gas pipelines above X60. Moreover,nonlinear finite element analysis method had small error,good centralization,stable distribution and low conservatism,which was suitable for all oil and gas pipelines of different steel grades and was the best in all evaluation methods.