Experiences gained from CO2 flooding to improve oil recovery worldwide indicates that considerable amount of remaining oil can be recovered with miscible CO2 injection under appropriate conditions. Though its performance in the heterogeneous Middle Eastern carbonate reservoirs has not been well demonstrated yet, it is most likely going to be the future hydrocarbons recovery process in Abu Dhabi after the successful implementation of the first miscible CO2-EOR pilot in 2009 by ADNOC Onshore. In 2016, ADNOC Onshore embarked on field scale implementation of CO2 injection; making it an integral part of the company's overall strategy to utilize CO2 as one alternative option to the expensive HC gas and address related key technical and business aspects.
The currently implemented CO2-EOR has been facing several complexities and challenges including, but not limited to, sustainability of CO2 supply, achieving miscibility conditions, optimization of production and injection, reservoir modeling issues, HSE risks, suitability of monitoring strategy, keeping the CO2 concentration levels within the existing plan design limits, maintaining the integrity of the facilities, associated operating costs and expansion of field development by CO2-EOR.
A number of mitigation plans and actions have been also put in place to ensure the smoothness of operations and therefore maintain the positive impacts of enhanced oil recovery by CO2 injection. Strong management support, multi-disciplinary data integration, continuous surveillance and pro-activeness are considered as the pillars for CO2-EOR success. This work aims to discuss the lessons learned from the ongoing development of CO2-EOR, after 2 years of implementation, and the way forward for the future development phases.