This document describes and explains the physical and chemical phenomena, and the technical issues associated with flow assurance in the various components of a carbon dioxide capture and storage (CCS) system and provides information on how to achieve and manage flow assurance. The gaps in technical knowledge, limitations of the tools available and preventative and corrective measures that can be taken are also described.

This document addresses flow assurance of CO₂ streams in a CCS project, from CO₂ capture via transport by pipeline and injection well through to geological storage. It does not specifically address upstream issues associated with CO₂ sources and capture, although flow assurance will inform CO₂ capture design and operation, for example, on constraints on the presence of impurities in CO₂ streams, as there are too many different capture technologies to be treated in detail in this document.

Vessel transport and buffer storage that are considered in integrated CCS projects under development, are not covered in this document. Flow of material in the supply chain of a CO₂ source, even if delivered by a pipeline (e.g. blue hydrogen generation), and flow of gas streams within facilities generating and feeding these into a capture facility can impact flow assurance in CCS projects and networks. These are out of the scope of this document as well.

This document also examines the impact of impurities on the phase behaviour and physical properties of the CO₂ stream which in turn can ultimately affect the continuous supply of the CO₂ stream from the capture plant, through the transportation system and into the geological reservoir via injection wells.

Flow of fluids in oil reservoirs for the purpose of enhanced oil recovery is not within the scope of this document.