| Abstract |
Leveraging methane (CH4) and CO2 to displace oil from unconventional reservoirs presents an opportunity to simultaneously reduce anthropogenic greenhouse gas emissions and create economic value from extracted oil. To optimize gas entrapment in such formations, it is crucial to uncover the fundamental mechanisms that govern flow diversion accountable for the injected fluid migration and oil mobilization. In this study, we focused on the flow diversion mechanisms established by CH4- and scCO2-foam injections in oil-wet propped–fractured carbonates. The fluid most susceptible to flow redirection was identified by quantifying the in situ fluid saturation in the matrix upon the completion of foam injection at varying gas fractional flows (fg = 0.4–0.8). We found that at high fg both CH4- and scCO2-foams selectively diverted surfactant solution from the fracture to the matrix. During CH4-foam injection, decreasing the injected gas fraction stimulated additional flow diversion of the surfactant solution but failed to reroute the gas flow from the fracture to the matrix. By contrast, scCO2-foam flooding was able to induce significant gas invasion into the matrix at fg < 0.7 but with negligible penetration of the surfactant solution. It was also identified that the pore space of the matrix previously occupied by the oil provided potential storage for the scCO2. The pore-scale fluid configurations indicated that the mobilization of matrix oil at higher fg was primarily driven by two-phase displacement mechanisms while at lower fg it became more complex, combining the effects of two- and three-phase displacement processes. |
| Authors |
Alvinda Sri Hanamertani   , Abdelhalim Mohamed , Soheil Saraji , Mohammad Piri
|
| Journal Info |
American Chemical Society | Industrial & Engineering Chemistry Research
|
| Publication Date |
4/13/2024 |
| ISSN |
0888-5885 |
Type |
article |
| Open Access |
closed
|
| DOI |
https://doi.org/10.1021/acs.iecr.3c04405 |
| Keywords |
Fracture Conductivity (Score: 0.52634) , Fracture Permeability (Score: 0.502663)
|
