Abstract
In this paper, the immiscible water-alternating-CO2 flooding process at the LH11-1 oilfield, offshore Guangdong Province, was firstly evaluated using full-field reservoir simulation models. Based on a 3D geological model and oil production history, 16 scenarios of water-alternating-CO2 injection operations with different water alternating gas (WAG) ratios and slug sizes, as well as continuous CO2 injection (Con-CO2) and primary depletion production (No-CO2) scenarios, have been simulated spanning 20 years. The results represent a significant improvement in oil recovery by CO2 WAG over both Con-CO2 and No-CO2 scenarios. The WAG ratio and slug size of water affect the efficiency of oil recovery and CO2 injection. The optimum operations are those with WAG ratios lower than 1:2, which have the higher ultimate oil recovery factor of 24%. Although WAG reduced the CO2 injection volume, the CO2 storage efficiency is still high, more than 84% of the injected CO2 was sequestered in the reservoir. Results indicate that the immiscible water-alternating-CO2 processes can be optimized to improve significantly the performance of pressure maintenance and oil recovery in offshore reef heavy-oil reservoirs significantly. The simulation results suggest that the LH11-1 field is a good candidate site for immiscible CO2 enhanced oil recovery and storage for the Guangdong carbon capture, utilization and storage (GDCCUS) project.
Highlights
In recent years, with the increase of energy consumption, global CO2 emissions have reached33.1 Gt in 2018 [1], which indicates a serious situation in fighting global climate change
CO2 immiscible water-alternating-gas (IWAG) projects have been implemented with varying water alternating gas (WAG) ratios and gas slug sizes, resulting in incremental reserves ranging from 2% to 9% and oil recovery from 14% to 20% [4]
During preliminary evaluation of the CO2 storage potential and site screening for the Guangdong offshore CO2 utilization and storage project, we found that there is potential for a possible application of CO2 IWAG in the Liuhua 11-1 (LH) oilfield in the Pearl River Mouth Basin (PRMB) of the northern
Summary
With the increase of energy consumption, global CO2 emissions have reached. Several CO2 IWAG studies and pilot test projects have been implemented in offshore oilfields such as the Dulang field offshore Malaysia [5], E field offshore west Africa [6], western India offshore [7] and the North Sea [8,9] These indicate that the CO2 IWAG applications in offshore oilfields are beneficial for oil recovery and CO2 storage, and receiving significant attention. A 3D geological model for the LH field was built and compositional simulations for varying WAG injection scenarios (including Continue CO2 and a No-CO2 scenarios) were performed to predicate and evaluate the process of CO2 -EOR and storage This is the first attempt to evaluate the potential of immiscible CO2 -EOR and storage potential in the PRMB at the full field scale. We hope that the results could provide a guidance for further development of the Guangdong offshore CO2 -EOR and storage in the PRMB, as well as global offshore CCUS project
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
