CCUS systems are already in operation around the world and typically involve the capture of CO2 and then transportation to underground storage wells. In the UK this will likely include the reclassification of existing crude oil import lines to CCUS export lines. The design of CCUS systems is very challenging due to the effects of impurities on the fluid properties and the need to keep the fluid in a single phase in the pipeline. For example, increasing the impurity content from 1% to 3% can have a significant impact on the fluid density. As a result of this, selection of an Equation of State (EoS) to model the fluid needs careful consideration and Hydraulic Analysis are in the process of developing a specialised EoS within the core of our pipeline simulation software.
Whilst it can be straightforward designing and reclassifying a pipeline for a single source of CO2 based upon a single composition, the task is far more challenging when mixing different CO2 streams which will contain different levels of impurities and potentially variable flowrates. Under these circumstances, a specialised EoS will need to be developed or a different EoS will need to be used for each pipeline section.
Hydraulic Analysis are part of an Energy Institute Working Group looking into CCUS and we also hosted a roundtable session on CCUS at the EI Middle East HSE Forum in Dubai in 2019. One of the benefits of our pipeline simulation software is the ability to blend and mix different fluid streams in the pipeline and model the corresponding changes in fluid temperature, density, viscosity and Bulk Modulus.