Evaluation method of residual life of casing with corrosion defect in CO2 injection Wells

Abstract

With the hot development of CCUS project in major oil fields, CO₂ flooding technology is also developing continuously. CO₂ flooding needs to transform old oil field Wells into CO₂ Wells, and the residual life of casing with corrosion defects in old oil Wells needs to be evaluated. To solve this problem, the residual strength of casing with corrosion defects under the combined force is analyzed, and a finite element analysis model is established considering the material nonlinearity. It is found that the temperature difference and axial force will significantly reduce the residual strength of casing. The influence of corrosion rate and pitting pit radius on the residual life of CO₂ injection well is discussed. It is found that well H can continue to serve for 13 years after CO₂ injection. The research results can provide a theoretical basis for predicting the residual life of CO₂ injection Wells in old wells, and ensure the normal production and operation of CO₂ injection flooding development.