Overall, the [B.sub.h] values of the four fractures were enlarged by 3.4, 0.94, 1.4, and 1.2 times by the CFDE experiments, respectively.
For the CFDE experiments, dissolution rates of carbonate samples were related to the [Ca.sup.2+] concentration at the solid-liquid interface and the contact area (the reaction area) of the solid-liquid surface.
The Peclet and Damkohler numbers of the CFDE experiment are the highest [S.sub.3], and thus, the channelizing dissolution is the most notable of the four fractures.
The CFDE experiments and SEM images provide independent parameters to characterize the dissolution progress within the fracture from the sample scale to the microscale.
The photographs and 3D laser scanning images of the fracture surfaces before and after the CFDE experiments indicated that the samples developed distinct dissolution zones.
After the CFDE experiment, the hydraulic apertures ([B.sub.h]) of sample 1 ([S.sub.1]), sample 3 ([S.sub.3]), and sample 4 ([S.sub.4]) were enlarged by 3.4, 1.4, and 1.2 times, respectively.
The experiment results indicate that the dissolution pattern depends on the Peclet and Damkohler numbers for the CFDE experiments at different temperatures.
The initial surface mineral heterogeneity and texture strongly affect the dissolution rate and the location of preferential dissolution in the CFDE experiments.
Column (a) shows the photographs before the CFDE experiments.
Caption: Figure 8: Hydraulic apertures of the fractures over time during the CFDE experiments.
Caption: Figure 9: Dissolution apertures of the fractures over time during the CFDE experiments.