Strength Failure of CO2 Injection Tubular Strings Considering CO2 Phase Transition

Compared with traditional injection tubular strings, the stresses on CO2 strings are more complex. The results from field applications show that phase transition of fluid in is an important factor calculation temperature distribution and analysis string mechanics. Therefore, we propose a strength method for considers transition. We selected four oil China as examples to evaluate their safety. First, established coupled differential equations temperature, pressure, physical parameters according theory flow heat transfer. Then, used adaptive fuzzy neural network construct model calculating convection transfer coefficient this obtain high-precision coefficients under conditions flooding. analyzed injection-string deformations resulted piston, spiral bending, expansion, friction effects stress characteristics packers different working conditions. Finally, performed mechanical analyses collapse resistance, internal pressure tensile triaxial these provide theoretical basis strings.