# Pressure and viscosity logs for permeability estimation of P3 and P4 samples. Experimental permeability values. 2D optical scans of beads1 and beads2.

‘pressure_transducer_logs.rar’ contains pressure logs of Heise DXD transducer used to estimate permeability for the P3 and P4 samples. The folders inside are named as %S%_visco%NU%, where %S% is the sample name and %NU% is the viscosity value of a given water–glycerol solution used in the permeability measurements. There are three solutions with the viscosities of 21, 38, 55 mPa*s. Inside each folder (say, ‘p3_visco38’) there are 16 files with the high frequency (~40Hz) (time_in_seconds, pressure_in_kPa) logs for the actual measurement and 16 files with the low frequency (1/60Hz) (time, pressure, temperature) logs acquired between the permeability measurements.

The high-frequency logs are named as %ExpN%_%Q%ml, where %ExpN% is the experiment No. and %Q% is the discharge in ml/min. For example, ‘p3_visco38\6_4_5ml.csv’ contains the data for the P3 sample, 38mPa*s solution, and Exp. No. 6 with the 4.5ml/min discharge rate.

The low-frequency logs are named as ‘ambient_after%ExpN%.csv’, where %ExpN% is the experiment number after which a given log file was recorded. The units for each column are described inside each low-frequency log file. The logged temperature values are approximate. The actual temperature readings used for the viscosity estimations were taken from the Fluke digital thermometer, which did not write the values directly into a file.

‘rheometer_viscosity_logs.rar’ contains the viscosity values measured with Anton Paar MCR 302 rheometer. Each .xlsx file inside this archive is named as %S%_visco%NU%.xlsx, where %S% is the porous sample name (P3 or P4) and %NU% is the solution viscosity. The solutions are water–glycerol with the approximate mass ratios of 119:51 (%NU%=21), 76.5:23:5 (%NU%=38), 80:20 (%NU%=55). For each sample P3 or P4 and each mass ratio, water and glycerol were mixed separately and therefore the resulting viscosity values differ slightly. Each %S%_visco%NU%.xlsx is an Excel file with at least 3 sheets named as ‘CC…’ and one ‘CC all’. Each ‘CC…’ sheet contains logs for one 19ml sample of a given solution measured at shear rates of 20/s and 50/s. ‘CC all’ summarizes given three measurements, averaging them and providing linear fit coefficients for the viscosity–temperature dependency. Those coefficients (for 20/s shear only) are used in the ‘permeability_calculation.xlsx’ to obtain viscosity values for each temperature, solution, and sample.

‘permeability_calculation.xlsx’ is the excel table with all the data used for experimental permeability calculations, including the pressure logs from ‘pressure_transducer_logs.rar’ and the linear viscosity–temperature dependencies from ‘rheometer_viscosity_logs.rar’. It also contains the data on simulated permeability values for the full systems, S3 and S4.

‘beads_2d_scans.rar’ contains .tif images of the optical scans for beads1 and beads2 placed on an adhesive tape. The coordinates and diameters of beads were approximated using ‘imfindcircles’ MATLAB routine, and the result is stored in a .mat file inside each folder. There are four scans for each beads type, containing about 4000 circles per scan. The following example shows how to visualize beads and the corresponding circles from ‘beads1_5’ folder after loading ‘cir_rad5.mat’ into MATLAB:

img = imread('TileScan 019_TileScan_001_Merging_Crop.tif');

figure; imshow(img);

viscircles(cir, rad, 'Color', 'r', 'LineWidth', 1);

Related data sets: