Integrity and Safety Management Challenges of Supercritical CO2 Pipeline Transportation at Offshore Platforms

In response to China’s dual carbon call, the petroleum industry is committed to green transformation, promoting the energy green revolution, focusing on domestic offshore CO2-enriched oil and gas reservoirs, and carrying out offshore platform carbon capture, utilization, and storage–enhanced oil recovery (CCUS-EOR) pilot projects. CO2 continuously displaces crude oil while being injected into deep-sea oil and gas reservoirs for carbon sequestration, achieving an increase in oil recovery and residual oil recovery. However, the implementation of offshore CCUS-EOR technology relies on the safe transportation of supercritical CO2 pipelines. Due to the unique physical and chemical properties of supercritical CO2, the safe transportation of supercritical CO2 pipelines faces multiple threats. This paper focuses on the current status of safe transportation technology for supercritical CO2 pipelines on offshore platforms, and summarizes multiple operational challenges, including obtaining high CO2 gas sources, high construction costs of pipelines, complex phase change of media, and internal and external corrosion of pipelines. The risk factors for failure of supercritical CO2 pipelines on offshore platforms were systematically identified, and the mechanism of leakage hazards of supercritical CO2 pipelines was determined. Based on the six-step cycle of pipeline integrity management, a targeted integrity management method for supercritical CO2 pipelines on offshore platforms is proposed, providing reference for improving the safety transportation technology system of supercritical CO2 pipelines on offshore platforms.