|Publisher||Society of Petroleum Engineers||Language||English|
|Content Type||Conference Paper|
|Title||Retardation of CO2 Migration due to Capillary Pressure Hysteresis: a New CO2 Trapping Mechanism|
Y. B. Altundas, T. S. Ramakrishnan, Nikita Chugunov, and Romain de Loubens, Schlumberger-Doll Research
SPE International Conference on CO2 Capture, Storage, and Utilization, 10-12 November 2010, New Orleans, Louisiana, USA
2010. Society of Petroleum Engineers
|6.8 Fundamental Research in Reservoir Description and Dynamics
6.5 Reservoir Simulation
6.3 Fluid Dynamics
4.3 Underground Gas Storage
In the present work, a self-consistent relative-permeability capillary-pressure hysteresis model is incorporated within a simulator. With this model, it is possible to compare and contrast hysteresis induced retardation to other mechanisms of trapping. The self-consistent parametrization of all of the transport properties is used to quantify sensitivity compactly. The sensitivity of the CO2 plume shape and the amount of CO2 trapped, to the strength of the capillary pressure hysteresis, is also described.
Simulated results show that CO2 plume shape with and without capillary pressure hysteresis are significantly different. As expected, capillary pressure hysteresis retards the buoyant transport of the CO2 plume. Although a portion of the CO2 is connected, and therefore not residual, the plume remains immobile for all practical purposes. Also, due to decreased driving potential, gravity tonguing below the caprock is reduced in comparison to the case without capillary pressure hysteresis, thus suggesting enhanced storage efficiency. However, the total dissolution of CO2 in saline water is reduced because of the reduced diffusive transport of CO2 within the brine. Thus, one mechanism of containment is offset by the other. Inclusion of accurate hysteresis models is important for qualifying storage sites constrained by spatial domain limits. It is anticipated that site acceptability criteria would change as a result of this study, thus impacting risk evaluation.
|File Size||1,314 KB||12|