EXPERIMENTAL DETERMINATION OF POROPERM PROPERTIES OF FRACTURED POROUS GEOMATERIALS WITHIN THE FRAMEWORK OF DUAL-PERMEABILITY MODEL
L. A. Nazarov1, N. A. Golikov1, A. A. Skulkin1, L. A. Nazarova2
1Novosibirsk State University, Novosibirsk, Russia
2Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Fractured porous rock mass, laboratory experiment, manmade geomaterial, regular layered sample, permeability, matrix, fractures, mass transfer coefficient, stress
Abstract
The experimental procedure is developed and tested on a laboratory scale and using layered samples of manmade geomaterials. Within the dual-permeability model, the procedure enables determining parameters that govern fluid flow and poroelastic deformation in fractured porous rock masses, namely, fracture permeability k1 and mass transfer coefficient β, as well as their dependence on stresses σ. The testing procedure is proposed and implemented. In the procedure, under the stepwise increasing normal stress σ, the stationary flow rates Q1(σ) and Q2(σ) are measured in a quasiregular fractured porous sample at the preset pressure difference: using a standard setup (Q1) and in closed end-face fractures (Q2). The mathematical model of the experiment is constructed, and the analytical solution of the problem on stationary flow is obtained: pressure patterns in fractures, and stress-dependence of flow rates. The experimental data interpretation algorithm enables calculating k1 and β by the recorded flow rates Q1 and Q2. It is shown that the permeability k1 is proportional to σ -2, and β remains almost unchanged.
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