Experimental Investigation of Gas Dynamic Effects Using Nanoporous Synthetic Materials as Tight Rock Analogues

Abstract To improve the understanding of gas transport processes in tight rocks (e.g., shales), systematic flow tests with different gases were conducted on artificial micro- to nanoporous analogue materials. Due rigidity these systems, fluid-dynamic effects could be studied at elevated pressures without interference poro-elastic effects. Flow narrow capillaries did not reveal any viscosity anomaly a confined space down capillary diameters 2 µm. Experiments ceramic disks (> 99% Al O 3 ) confining from 10 50 MPa indicate stress dependence permeability coefficients. Analysis apparent coefficients over mean pressure range 0.2 30.5 showed essentially linear Klinkenberg trends no indication second-order slip flow. The Klinkenberg-corrected measured helium consistently higher than those all other under same conditions. This “helium anomaly” was, however, less pronounced effect observed natural rocks, indicating that it is probably related but rather gas–solid interactions sorption). Permeability CO membrane show significant deviations trend around critical point. due drastic changes thermodynamic properties, particular isothermal compressibility, this and temperature range. Helium pycnometry, mercury intrusion porosimetry low-pressure nitrogen sorption good agreement terms porosity (~ 28%) most prominent pore diameter 68.5 nm).