Assessing Impacts on Pressure Stabilization and Leasing Acreage for CO2 Storage Utilizing Oil Migration Concepts

Assessing Impacts on Pressure Stabilization and Leasing Acreage for CO2 Storage Utilizing Oil Migration Concepts

Gasoline

Carbon dioxide

Offshore oil well production

Petroleum reservoirs

Geology

Offshore oil wells

Stabilization

Petroleum reservoir evaluation

Injection (oil wells)

Seismology

Well logging

Favorable geological storage for CO2 has long been pictured as large anticlines with thick sandstones, similar to oil reservoirs in the petroleum system. Unlike oil, however, stored CO2 does not need to be recoverable, which raises the possibility of using dissolution and residual trapping to augment the capacity of buoyant traps and tap more of the bulk rock volume. The work presented builds on that idea, asking the following question: If we inject CO2 down to a syncline analogous to the carrier bed in the petroleum system how would this injection mechanism impact storage capacity and plume shape, migration, and stabilization? To address this question, we built a reservoir model, based on seismic interpretation of Middle Miocene strata, offshore Galveston, Texas. 3-D seismic and well logs were used to characterize key intervals. Reservoirs chosen for modeling are progradational-aggradational sands with mud intercalation. They have a higher degree of heterogeneity than the more conventional reservoirs commonly targeted for CO2 storage. Modeling investigated how far the CO2 plume would migrate under two scenarios: (1) injecting CO2 at the base of the salt withdrawal basin (syncline scenario) and (2) injecting CO2 at the base of the structural closure, similar to a common injection well location for EOR purposes (base scenario). For each scenario, we separately simulated injection of 30 MT of CO2 and 60 MT of CO2 continuously for 30 years and observe the plume and pressure evolution for 100 years after the injection stops. The simulation shows that injecting the CO2 into a syncline limits the vertical migration of CO2, thus making synclinal injection more secure. In the syncline scenario, the geological layer around the injection point is more heterogeneous than the layer in the base scenario

thus, the CO2 tends to migrate laterally. Additionally, in the syncline scenario, the plume does not even reach the upper part of the anticline, allowing us to safely store an additional amount of CO2 into the reservoir. Moreover, the simulation also shows that in the syncline scenario, the times needed for the reservoir to reach its stabilized pressure after the end of injections are faster. To summarize, CO2 injection at the base of a syncline could provide additional storage, increase the safety of the project from the limited vertical plume migration, and expedite plume stabilization, which could result in the decrease of monitoring frequency as the project runs, thus lowering the operating cost of the project in the long run. 2022 Elsevier Ltd

115

International Journal of Greenhouse Gas Control

2022

Ulfah, Melianna

Hosseini, Seyyed

Hovorka, Susan

Bump, Alex

Bakhshian, Sahar

Dunlap, Dallas

journalArticle

17505836

10.1016/j.ijggc.2022.103612