(538c) Optimizing Pore Space Utilization with Foam for Carbon Storage in Powder River Basin Near the Dry Fork Station

Significant storage capacity is necessary for carbon storage projects. Projects that consider optimizing storage in the available pore space through the effective displacement of formation brines will increase storage capacity and storage efficiency. Previous experiments have shown that incorporating foam during CO₂ injection could help optimize storage potential, with improved pore space utilization demonstrated in . However, foam behaves differently based on the connectivity of the rock and rock type. For example, it is generally challenging to generate high viscous foam in lower permeability reservoirs. This study will present the experimental results of foam-improved CO₂ storage in three storage formations at the Wyoming CarbonSAFE site. These injection formations have lower permeability than the Berea Sandstone, so pore space optimization is a significant project goal.

To analyze the feasibility of incorporating CO₂ foam in Wyoming CarbonSAFE target formations (Lakota, Hulett, and Minnelusa formations), the injection response of CO₂ at reservoir conditions (temperature and pressure ranging 81.1–94.4 °C and 2,923–4,007 psi) with foam technique will be assessed along with the dynamic foam performance evaluation. The CO₂ storage potential relative to optimization techniques is defined by CO₂ breakthrough deceleration and water displacement efficiency. The dynamic performance of CO₂-foams stabilized by a selected sultaine-based zwitterionic surfactant will be evaluated in target formation core plugs using the CO₂/surfactant co-injection method. Samples from the Berea Sandstone provides the comparative analysis.

Preliminary experimental results show that the CO₂ storage potential of the tests that did not incorporate the foam technique of Lakota, Hulett, and Minnelusa samples are averaged at 43.5%, 44.0%, and 55.2%, respectively. Meanwhile, immediate foam generation was observed in Berea Sandstone samples at 90 °C and 2,000 psi, providing high flow resistance for the injected CO_2. This resulted in controlled CO₂ mobility and improved CO₂ trapping—i.e. improved access to pore space through brine displacement and CO₂ retention. The CO₂ storage potential increased nearly twofold with the selected sultaine-based zwitterionic surfactant in Berea Sandstone. Thus, further study is expected to provide the foam-improved CO₂ storage results in the target reservoir rocks, which improves our understanding of the foam-improved carbon storage for the actual reservoir rocks with varying permeability under the reservoir conditions. It will also provide a well-understood option for CCUS projects that need better CO₂ mobility control.