Challenges Associated with Flow Assurance Modeling of CO_2-Rich Pipelines

摘要

CO_2 and CO_2-rich pipelines are a key part of any Carbon Capture and Storage (CCS) system. Generally flow assurance modeling of these pipelines has been restricted to pure CO_2 systems, however natural and anthropogenic sources of CO_2 often contain impurities. These impurities can have a dramatic effect on fracture mechanics and also the corrosion threats within the pipelines. Therefore it is important that modeling of flow and phase behavior of the CO_2 with impurities is performed. Modeling of a CO_2-rich pipeline is challenging due to the lack of previous experience and the phase behavior of CO_2 rich systems. Estimation of transport properties around the critical point and phase boundaries is particularly difficult. Benchmarked thermodynamic and transport property correlations are available in the public domain, published by the numerous research groups and institutes. The methodology presented shows how these data can be used in a conventional multiphase transient flow assurance package. The results produced from Flow Assurance modeling following this method are equivalent in accuracy to multiphase hydrocarbon modelling, as typically performed within the oil and gas industry. The methodology is presented in step-by-step detail, highlighting critical challenges and providing workarounds for gaps in existing knowledge. This allows the authors to assess the flow assurance and phase behavior effects on corrosion in a more accurate manner.