Burst Pressure Prediction of Subsea Supercritical CO 2 Pipelines.

To improve transportation efficiency, a supercritical CO 2 pipeline is the best choice for large-scale and long-distance transportation inshore and offshore. However, corrosion of the pipe wall will occur as a result of the presence of free water and other impurities present during CO 2 capture. Defects caused by corrosion can reduce pipe strength and result in pipe failure. In this paper, the burst pressure of subsea supercritical CO 2 pipelines under high pressure is investigated. First, a mechanical model of corroded CO 2 pipelines is established. Then, using the unified strength theory (UST), a new burst pressure equation for subsea supercritical CO 2 pipelines is derived. Next, analysis of the material's intermediate principal stress parameters is conducted. Lastly, the accuracy of the burst pressure equation of subsea supercritical CO 2 pipelines is proven to meet the engineering requirement by experimental data. The results indicate that the parameter b of UST plays a significant role in determining burst pressure of pipelines. The study can provide a theoretical basis and reference for the design of subsea supercritical CO 2 pipelines.