The objective of the study was to assess monetization opportunity in existing gas processing facilities by recovering CO2 from the acid gas stream and utilizing it to enhance oil recovery. This could potentially lead to generating more revenues with minimum modifications and optimizing the plot footprint, energy, and overall cost, all while maintaining business continuity.
The Study was conducted in two stages:
Feasibility Study was carried out to identify a potential site location and UTC per ton of potential recovered CO2 to meet pilot phase EOR requirement of upstream oil facilities. Study recommended to recover CO2 from existing AGRU Regenerator overhead using chemical solvents, TEG dehydration and compression.
Pre-Feed Study – The developed idea along with other potential options were thoroughly evaluated by a Pre-FEED Study to select the most techno-economic viable location, technologies and overall process configuration in order to capture CO2 to meet upstream oil company pilot phase requirements for EOR.
The final selected concept for CO2 capture was as per followings:
Low pressure chemical solvent type CO2 capture Unit located downstream of the AGRU but upstream of the flash / recovered flare gas tie in;
Wet CO2 compression to TEG dehydration unit and dry CO2 compression transport for injection;
Reinject enriched H2S from the CO2 capture unit to condensate reservoir
The selected concept UTC US$ / MT of CO2 compared by performing similar exercises for other two sites and it is observed that UTC varies depending on existing process and utilities systems configuration, feed gas quality and product specifications.
Concept of recovering CO2 from existing oil & gas facilities for EOR facilitates minimizing CO2 emissions and its footprint.
This concept can potentially be enhanced by taking calculated risks and applying emerging technologies with Licensors’ to ease UTC from its current level and complement other by-products to enhance overall value chain in energy sector. In addition to that this, UAE has set the National Climate Change Plan 2017–2050 that serves as a roadmap to boost nationwide actions for climate mitigation. Capturing CO2 for EOR economically will facilitate UAE to minimize carbon emission footprint.
Based on aforementioned Pre-FEED study, this paper identifies and evaluates the most viable options for the CO2 capture unit location, CO2 capture technology, CO2 dehydration and transport technology and H2S handling for the entire operating envelope. This paper also provides an overview of the CO2 dehydration unit optimum operating pressure, discussions on CO2 wet and dry compressors and the configuration of the CO2 capture train(s).