Implications of pore microgeometry heterogeneity for the movement and chemical reactivity of CO2 in carbonates
We studied the heterogeneity of natural rocks with respect to their pore-size distribution, obtained from mercury-intrusion capillary pressure (MICP) tests, at a scale about one-fifth of the standard plug size (2.5 cm). We investigated two Fontainebleau sandstone and two limestone samples. We found...
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| Format: | Journal Article |
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Society of Exploration Geophysics
2013
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| Online Access: | http://hdl.handle.net/20.500.11937/22744 |
| _version_ | 1848750956420792320 |
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| author | Vialle, Stephanie Dvorkin, J. Mavko, G. |
| author_facet | Vialle, Stephanie Dvorkin, J. Mavko, G. |
| author_sort | Vialle, Stephanie |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We studied the heterogeneity of natural rocks with respect to their pore-size distribution, obtained from mercury-intrusion capillary pressure (MICP) tests, at a scale about one-fifth of the standard plug size (2.5 cm). We investigated two Fontainebleau sandstone and two limestone samples. We found that at the scale of the MICP tests, heterogeneities are practically nonexistent. Still, there are large differences in the capillary curves from one rock type to another. Also, carbonate rocks, unlike Fontainebleau sandstone, show heterogeneities at a scale smaller than the scale used in MICP tests, as seen by the complexity in the mercury saturation versus pressure curves. We used this diversity between the capillary curves and this complexity within a single capillary curve to obtain information about the movement and chemical reactivity of CO2 in carbonates.The method consists of three steps: first, subdividing the carbonate pore system into microstructural facies, each of them having a specific range of pore throat size (e.g., tight micrite, microporous rounded micrite, small vugs, …); second, getting a characteristic value of their petrophysical properties (namely porosity, effective surface area, and permeability) from the collected MICP data; and third, computing, for experimental conditions corresponding to a transport-controlled system, the dimensionless Péclet and Damköhler numbers, expressed as a function of the aforementioned permeability and effective surface area. These numbers allowed us to infer the dominant process (i.e., diffusion, advection, or kinetics) controlling the dissolution/precipitation reaction induced by the carbonic acid. Because of heterogeneities in the pore microstructure, we found that either diffusion or advection is locally the dominant mechanism, which renders some zones (e.g., vugs or, to a lesser extent, microporous rounded micrite) chemically more reactive than others (e.g., tight micrite or spar cement). |
| first_indexed | 2025-11-14T07:45:04Z |
| format | Journal Article |
| id | curtin-20.500.11937-22744 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:45:04Z |
| publishDate | 2013 |
| publisher | Society of Exploration Geophysics |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-227442017-09-13T13:57:04Z Implications of pore microgeometry heterogeneity for the movement and chemical reactivity of CO2 in carbonates Vialle, Stephanie Dvorkin, J. Mavko, G. We studied the heterogeneity of natural rocks with respect to their pore-size distribution, obtained from mercury-intrusion capillary pressure (MICP) tests, at a scale about one-fifth of the standard plug size (2.5 cm). We investigated two Fontainebleau sandstone and two limestone samples. We found that at the scale of the MICP tests, heterogeneities are practically nonexistent. Still, there are large differences in the capillary curves from one rock type to another. Also, carbonate rocks, unlike Fontainebleau sandstone, show heterogeneities at a scale smaller than the scale used in MICP tests, as seen by the complexity in the mercury saturation versus pressure curves. We used this diversity between the capillary curves and this complexity within a single capillary curve to obtain information about the movement and chemical reactivity of CO2 in carbonates.The method consists of three steps: first, subdividing the carbonate pore system into microstructural facies, each of them having a specific range of pore throat size (e.g., tight micrite, microporous rounded micrite, small vugs, …); second, getting a characteristic value of their petrophysical properties (namely porosity, effective surface area, and permeability) from the collected MICP data; and third, computing, for experimental conditions corresponding to a transport-controlled system, the dimensionless Péclet and Damköhler numbers, expressed as a function of the aforementioned permeability and effective surface area. These numbers allowed us to infer the dominant process (i.e., diffusion, advection, or kinetics) controlling the dissolution/precipitation reaction induced by the carbonic acid. Because of heterogeneities in the pore microstructure, we found that either diffusion or advection is locally the dominant mechanism, which renders some zones (e.g., vugs or, to a lesser extent, microporous rounded micrite) chemically more reactive than others (e.g., tight micrite or spar cement). 2013 Journal Article http://hdl.handle.net/20.500.11937/22744 10.1190/GEO2012-0458.1 Society of Exploration Geophysics restricted |
| spellingShingle | Vialle, Stephanie Dvorkin, J. Mavko, G. Implications of pore microgeometry heterogeneity for the movement and chemical reactivity of CO2 in carbonates |
| title | Implications of pore microgeometry heterogeneity for the movement and chemical reactivity of CO2 in carbonates |
| title_full | Implications of pore microgeometry heterogeneity for the movement and chemical reactivity of CO2 in carbonates |
| title_fullStr | Implications of pore microgeometry heterogeneity for the movement and chemical reactivity of CO2 in carbonates |
| title_full_unstemmed | Implications of pore microgeometry heterogeneity for the movement and chemical reactivity of CO2 in carbonates |
| title_short | Implications of pore microgeometry heterogeneity for the movement and chemical reactivity of CO2 in carbonates |
| title_sort | implications of pore microgeometry heterogeneity for the movement and chemical reactivity of co2 in carbonates |
| url | http://hdl.handle.net/20.500.11937/22744 |