2024-03-29T12:15:12Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/944852020-07-09T10:00:33Zcom_10261_5062com_10261_5col_10261_5070
Mixing-induced dissolution in unstable reactive flow
Hidalgo, Juan J.
Cabeza, Y.
Dentz, Marco
Carrera, Jesús
Ponencia presentado en la American Geophysical Union Fall Meeting, celebrada en San Francisco del 9 al 13 de diciembre de 2013.
The evolution of porosity in carbonate reservoirs during CO2 injection, and the wormhole formation in karst aquifers can be attributed to fast equilibrium reactions, which are characterized by large Damköhler numbers. Under these conditions the reaction rate is mixing-controlled, and can be quantified in terms of the mixing rate of the conservative components of the chemical system [De Simoni et al. (2005), Water. Resour. Res.]. Here, we study the calcite dissolution during the convective-driven mixing of CO2 in a carbonate aquifer. We derive an analytical expression for the speciation contribution to the reaction rate which is valid under a wide range of reservoir conditions (pH<8.3). This allows us to analyze systematically the impact of conservative mixing mechanisms on the dynamics of the complex reactive flow system. We explore the evolution of the porosity and the permeability by means of numerical simulations of a CO2 stationary layer dissolving into brine using an analogue-fluid system with a non-monotonic density-concentration curve [Neufeld et al. (2010), Geophys. Res. Lett.; Backhaus, et al. (2011), Phys. Rev. Lett.; Hidalgo et al. (2013), Adv. Water Resour.]. Our findings show how the developed porosity patterns depend on the fingering instabilities caused by the convective-driven dissolution of the CO2, the movement of the receding CO2-brine interface, and the properties of the chemical system.
2014-03-31T07:03:12Z
2014-03-31T07:03:12Z
2013-12
comunicación de congreso
American Geophysical Union Fall Meeting (2013)
http://hdl.handle.net/10261/94485
eng
info:eu-repo/grantAgreement/EC/FP7/282900
closedAccess
American Geophysical Union