Research on Multi-condition Load Prediction of Fracturing Stimulation Tubing String and Tubing Applicability Evaluation for High-Temperature and High-Pressure Wells

Abstract

The fracturing operations of high-temperature and high-pressure (HTHP) oil wells are constrained by two critical factors: first, the insufficient accuracy of string mechanics parameters; second, the undefined applicability of design schemes under complex downhole operating conditions. To address these challenges, this study draws on classical string mechanics theory and incorporates five key mechanisms, namely the piston effect, ballooning effect, friction effect, temperature effect and helical buckling effect. It further conducts systematic calculations on string loads across five operational stages: tubing running, circulation, packer setting and seal test, fracturing, and production. The safety factor method is adopted to verify the reliability of the string design scheme. Meanwhile, the study identifies the high-risk zones and their corresponding load values of the well intervals equipped with new-type tubing, laying a solid foundation for subsequent tubing performance verification. In conclusion, this research provides a solid theoretical basis and technical support for the optimization of string design and the safety assurance of fracturing operations in HTHP oil wells.