油管套管抗内压强度计算研究

Study on internal pressure strength prediction for casing and tubing

孙永兴 林元华 杨晓峰 杨博仲 余来红 齐玉

SUN Yongxing LIN Yuanhua YANG Xiaofeng YANG Bozhong YU Laihong QI Yu

川庆钻探工程公司钻采工程技术研究院，四川广汉　618300 西南石油大学石油管工程重点实验室，四川成都　610500 川庆钻探工程公司科技处，四川成都　610051

CCDC Drilling & Production Engineering Technology Research Institute, Guanghan 618300, China The Key Laboratory of Mechanical and Environmental Behavior of Tubular Goods, SWPU, Chengdu 610500, China

高温高压高含硫气井中的油管、套管一旦爆裂失效，将可能导致油套串通，甚至含硫气体串出地面，危害性较大。因此，在油管、套管强度设计中，不但要合理地计算出最小的抗内压屈服强度，而且还要准确地预测出极限强度即爆裂强度。针对API Bulletin 5C3:1994屈服计算公式存在的不足以及ISO/TR 10400:2007爆裂强度计算模型计算精度不够理想的问题，根据屈强比（Y/T）对油管、套管爆裂失效强度影响规律，提出了具有更高精度的油管、套管抗内压爆裂计算新模型，通过与试验数据计算对比，证明了新模型的可靠性和合理性，对优化“三高”气井油管、套管抗内压强度设计提供了新的参考依据。

For wells with high pressure, high temperature, and high H2S, once the tubing or casing burst into failure, the gas may cross between tubing and casing, even the sulfur-containing gas may blow out to the ground, so the harm is self-evident. Therefore, an accurate prediction of the internal pressure strength is essential in tubing and casing design process. For high H2S gas wells, the API Bulletin 5C3 formular cannot satisfy with the design criteria, and the burst model for capped-end conditions has been provided in ISO10400, but some predictions by ISO burst model exceeds the actual burst strength. According to the significant influence of yield-to-tensile strength ratio Y/T on failure behavior of tubing or casing, a new internal pressure strength model is presented for casing and tubing with high calculation accuracy. The comparison work show that the results calculated by the new model essentially coincide with test burst data, which provides a powerful reference for optimizing strength design for casing and tubing.