CO2 EOR and Sequestration Potential in Mature Reservoirs, Daqing Oilfield, China

Zhang, Yunsheng
[email protected]

CO₂ miscible injection becomes more and more popular and mature in the past decades. CO₂ EOR plus sequestration is a new way in current days to increase the recovery and reduce the climate burden. The Fuyang field has quite a few low permeability sandstone reservoirs, which currently the water cut and oil rate are getting close to the economic limits after near three decades of water injection. Figuring out a superseded method is important to the control of production decline and the utilization of existing well networks.

This study is aimed at assessing the potential of CO₂ EOR and storage in three large oil fields in the region based on the data of 23 mature oil reservoirs. The assessments include a regional geology assessment, storage site screening, reservoir screening for CO₂ EOR and EOR potential and storage capacity calculations. Many mature oil reservoirs are close to the main CO₂ sources and have good geographical and geological conditions for CO₂ storage.

The investigation results show that 16 are suitable both for EOR and storage. And 5 reservoirs were found suitable for storage as depleted oil reservoirs. The total EOR potential could be 199.72×104 t of crude oil and the CO₂ storage potential could reach 1,553.92×104 t. The overall incremental oil recovery rate could be 7.92%. Those oil reservoirs with significant potential for CO₂ EOR and storage are targeted for the near future work.

This study is the first try in Daqing to consider both CO₂ EOR and Storage, which would definitely demonstrate the method to improve the development after water flooding in Fuyu reservoirs and also help with a good reference value to reduce the environmental stress in China.

AAPG Search and Discovery Article #90166©2013 AAPG International Conference & Exhibition, Cartagena, Colombia, 8-11 September 2013