Ductile fracture arrest of CO2 pipelines applied to CCUS technology

Abstract

CO2 pipeline transportation is the most economical and efficient way to realize CCUS (Carbon Capture, Utilization and Storage) technology, but there is a risk of ductile fracture during its operation due to engineering problems such as pipeline defects, fatigue and corrosion. In this study, a modified Battelle Two-Curve Model and a crack arrest performance evaluation model based on the crack arrest efficiency were established for the pipeline overall reinforcement structure and coaxial crack arrestor, respectively, and the models were verified experimentally to be reliable. Based on the supercritical CO2 pipeline transportation scheme designed for Yanchang Oilfield with storage capability of 4 million t/a, the crack arrest performance of five pipelines was evaluated. For the non-crackable pipelines, the pipeline overall reinforcement and the coaxial crack arrestor are applied, based on the crack arrest requirement and engineering economy, respectively. This study provides references and suggestions for the design and safe operation of supercritical CO2 pipelines containing impurities in the future.