Processed 3D Tomographic Images of Repeated CO2 and Brine injections into Layered Bentheimer Sandstone

Full description

The raw grayscale tomographic data volumes for all "initial" (post-CO2 injection) and "residual" (post-brine injection) scans were first registered to the dry tomographic data set to allow direct and precise comparison of phase distributions in each data set. Data volumes were cropped to a central region, and grayscale intensity variation (due to beam hardening and attenuation distortion due to high-density flow diffusers at the core ends) was corrected in radial and vertical directions. The dry scan was segmented into three phases (pore, solid grains, and clays) using converging active contours "CAC") segmentation routines. Three-phase segmentation (scCO2, brine, solid grains) was accomplished by overlaying the phase-labeled dry data set on all the registered initial and residual data volumes, and performing a final additional CAC routine to distinguish between scCO2 and brine, only on the regions labeled "pore" in the dry data set. Speckle noise removal was accomplished by removing scCO2-labeled clusters smaller than 234 voxels (equivalent to a sphere with a radius of 15.0 micron), and also by removing any isolated inclusions from within the scCO2 phase. Data is segmented and in .nc format (https://www.unidata.ucar.edu/software/netcdf/). For "DRY" data set: 0=void/pore space; 1=Sandstone grains For initial ("SI#") and residual (SR#) data: 0=scCO2; 1=brine; 2=sandstone grains 1000^3 voxel subsets of data were taken from the "top", "middle", and "bottom" regions of the core; these subsets are provided here. Data is labeled with the following nomenclature: segmentedHiRes_roi_CO2_injection_1_a_SStop_nc segmentedHiRes_roi_Brine_injection_1_SStop_nc "CO2" or "Brine" indicates the type of injection directly preceeding the scan acquisition; the numeral [1-4] indicates the cycle number, the letter [a-d] desginates the sequence of CO2 injections (for cycles with repeated CO2 injections) ; and the region is indicated directly. Full experimental details (including flow rates and scan types) are included in: A.L. Herring, Sun, C., Armstrong, R.T., and Saadatfar, M. "Insights into Wettability Alteration during Cyclic scCO2-Brine Injections in a Layered Bentheimer Sandstone", International Journal Greenhouse Gas Control (2022), DOI:10.1016/j.ijggc.2022.103803.

Notes

1.86 GB.

Significance statement

3D X-ray tomographic data acquired for over four scCO2-brine injection cycles into a layered Bentheimer sandstone; exhibiting changes in scCO2 morphology and distribution. The data provides insight into wettability alteration occuring during injections.