(118b) Time-Dependent Multi-Period Assessment of Life Cycle Cost and Environmental Impacts of CO2 EOR

 EOR (enhanced oil recovery) methods has been widely adopted for increasing oil production rate, and injection of CO₂ into the reservoir other than other mediums in EOR applications can be favorable in these days, due to CCS (carbon capture and sequestration). Although sustainable gains can be obtained from CO₂ EOR, considerable investment and energy consumptions are needed to accommodate CO₂ purchase, CO₂ injection, product separation and CO₂ recovery. Therefore, it is helpful to perform LCA (life-cycle analysis) for gathering an inventory of relevant energy and material inputs and environmental releases related to CO₂ EOR operation, and evaluating them in a systematic and integrated manner.

 A few studies conducted for life cycle analysis of CO₂ EOR have been mainly focused on compiling overall energy and material inputs for whole life time of EOR, and assessing total amount of CO₂ purchase, CO₂ recycle and oil production as a whole. These lumped life-time values may not be adequate for interpreting time-dependent and non-constant characteristics in EOR operations, for example, design and operation of surface facilities in CO₂ EOR, . Hence, in this study, multi-period approach considering time-dependent characteristics of CO₂ EOR operation is introduced for LCA. Process modeling for CO₂ EOR production facility is coupled with LCA, with which processing capacity and energy consumption can be simultaneously considered. Also multi-period consideration of material and energy inputs allows detailed interpretation of life time impacts of CO₂ EOR. A case study is presented to highlight the importance of time-dependent consideration on CO₂ EOR operation and to effectively quantify key economic and environmental trade-offs through LCA.

Acknowledgment

This work was supported by “The development of CO₂ geological storage technologies through 1,000 ton CO₂-EOR pilot test” of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Ministry of Trade, Industry and Energy (MOTIE) (No.2012T100201728).