Determination of the Low Permeability of the Rocks from Fracture Zones in Beishan by Incorporating ERT into Infiltration Test

Abstract:

The hydraulic study of low permeability rocks has a great significance for the low permeable oilfield and nature gas field development, as well as the nuclear waste disposal. The traditional test method for hydraulic parameters usually determines an average value of certain region, and this is always insufficient in the study of fractured porous media. This research developed a method with high performance and accuracy to show the heterogeneity and anisotropy of sample rocks. While permeability measurement was conducted, electrical resistivity tomography (ERT) method was incorporated simultaneously to obtain the rock saturation information, which could be used to determine the permeability. Besides, the infiltration process of water infiltrating through the fractured porous media was simulated by TOUGH2 to corroborate the results calculated from the experimental data. The preliminary results showed that the permeability of rock samples was as low as 10^-16 m² and showed high sample variance. By incorporating electrical resistivity tomography into the experiment, the test could specify more details of the infiltration process as well as identify the heterogeneity and anisotropy of sample rocks.