A Novel Approach to Assessing the Internal Cleanliness of Pipelines for CCUS Conversion with the Use of Visual Insight

Objective, Scope The repurposing of existing hydrocarbon pipelines for carbon dioxide (CO2) transportation in Carbon Capture, Utilization, and Storage (CCUS) projects presents both an opportunity and a technical challenge. Ensuring internal cleanliness is critical for safe and efficient CO2 transport, particularly given the corrosive potential of impurities and residual hydrocarbons. Traditional cleaning and verification methods offer indirect assurance of cleanliness. However, they often lack the ability to confirm uniform cleanliness along the entire pipeline length. Methods, Process This paper presents a novel, high-resolution, free-swimming video assessment tool that enables direct visual assessment of pipeline interior conditions. Believed to be the first field deployment of its kind globally, the system captures continuous 360-degree footage of the internal pipe wall over long distances without tethering or real-time data transmission. Prior to launch, the device is pre-programmed with pipeline requirements, enabling autonomous navigation and data logging. Results, Observations, Conclusions The technology was successfully applied to a 27-kilometer, 24-inch carbon steel pipeline originally designed for natural gas service and is undergoing conversion for CO2 transportation. Following a bespoke cleaning programme of brush pigs, foam pigs and batch cleaning fluids to ensure the removal of any pipeline debris, the video assessment tool was deployed to verify the pipeline's readiness. The captured footage provided operators and regulatory stakeholders with unequivocal, quantifiable visual evidence of internal cleanliness, supporting pipeline integrity certification and reducing uncertainty around repurposing decisions. This paper details the inspection methodology, operational setup, and findings from the case study. It also explores broader implications for CCUS infrastructure readiness and risk management. The technology represents a significant step forward in pipeline verification, offering a scalable, non-invasive, and data-rich approach to ensuring CO2 pipeline integrity. Novel/additive information The technique described in this paper involves the application of the world's first HD, multi-sideview array camera, providing complete pipeline visual coverage. This was combined with a bespoke data analysis and visualization suite, intuitive and interactive log, creating 2D and 3D models. Critically, it provides all stakeholders with indisputable evidence to allow them to plan and execute pipeline conversion from oil & gas service to transport CO2 reducing the need for new pipeline construction.