Modeling of CO2-CH4 Water Alternating Gas with Asphaltene Deposition for Estimating Coupled Performance of Enhanced Oil Recovery and Geological Carbon Storage
Abstract
This study develops a compositional simulation model of a water alternating gas (WAG) process that co-injects carbon dioxide (CO2) and methane (CH4)CO2-CH4 WAGfor asphaltene deposition in an oil reservoir. The effects of asphaltene deposition on the change in oil composition and associated formation damage are analyzed in terms of enhanced oil recovery (EOR) performance and carbon capture and storage (CCS) performance. Asphaltene precipitation and deposition mechanisms are examined based on fluid modeling results and compositional simulation results, respectively. Fluid modeling is performed using Burke Oil 1 experimental data with 19 API. Compositional simulation is conducted for a 13-year CO2-CH4 WAG case with one injector and one producer. For investigating the asphaltene effects, the CCS-EOR performance of the integrated CO2-CH4 WAG model is compared with those of CO2-CH4 WAG without asphaltene effects and of pure CO2 WAG. When considering asphaltene deposition, the addition of CH4 into the CO2 stream has advantages and disadvantages for oil recovery. Compared with pure CO2 WAG, the addition of CH4 decreases oil displacement efficiency due to the reduced miscibility while mitigating asphaltene deposition. This relief of formation damage compensates for oil recovery. The CCS performance of CO2-CH4 WAG with asphaltene deposition is investigated regarding residual and solubility trapping mechanisms. Residual and solubility trapping performance with asphaltene deposition are higher and lower than that without asphaltene, respectively, because asphaltene deposition causes a change in gas and water mobility. The overall carbon storage effect of CO2-CH4 WAG is quantified as a modified global warming potential (GWP). The results highlight the significance of asphaltene deposition modeling for an accurate evaluation of the performance of CO2-CH4 WAG as a CCS-EOR technology. Sensitivity analysis results also confirm that increasing CH4 concentration and WAG ratio enhances the performance of CCS-EOR.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMGC15A0655C