Determination of poro-perm properties of fractured-porous geomaterials based on non-steady filtration test data through inverse problem-solving within a dual-porosity medium model

A two-stage method is developed to validate geomechanical–hydrodynamic models of dual porosity and dual permeability (DPDP) media. The models aim to describe mass transfer processes in fractured-porous rock mass under quasi-static stresses. The method is theoretically substantiated and tested on a constructed universal laboratory bench using specimens made of artificial geomaterial by an original technology. At the first stage, the mass transfer coefficient, as well as the permeability of the matrix and fracture space are determined based on the results of deformation and stationary filtration tests of the specimens. A DPDP model of non-stationary filtration is developed and implemented using a finite-difference method, describing laboratory experiments. These experiments were carried out on block parallelepiped samples of a regularly layered structure under variable external stress , and consisted in recording the change in the pressure P(t,) over time in a reference volume under various outlet conditions. At the second stage, the compressibility of the matrix and the fracture space were determined based on the solution of inverse coefficient problems by the input data P(t,) within the DPDP model. The least square method reveals that the dependence of the fracture space compressibility on stresses is well approximated by a decreasing exponential function.

Nazarov L. A., Golikov N. A., Skulkin A. A., Nazarova L. A. Determination of poro-perm properties of fractured-porous geomaterials based on non-steady filtration test data through inverse problem-solving within a dual-porosity medium model. MIAB. Mining Inf. Anal. Bull. 2024;(12):5-17. [In Russ]. DOI: 10.25018/0236_1493_2024_12_0_5.

The study was supported by the Russian Science Foundation, Project No 23-27-00339.

L.A. Nazarov¹, Dr. Sci. (Phys. Mathem.), Chief Researcher, e-mail: mining1957@mail.ru, ORCID ID: 0000-0002-9857-295X,
N.A. Golikov¹, Cand. Sci. (Eng.), Senior Researcher, e-mail: golikovna@ipgg.sbras.ru, ORCID ID: 0000-0001-8101-230X,
A.A. Skulkin¹, Junior Researcher, e-mail: chuptt@yandex.ru,
L.A. Nazarova, Dr. Sci. (Phys. Mathem.), Chief Researcher, Chinakal Institute of Mining of the Siberian Branch of the Russian Academy of Sciences, 630091, Novosibirsk, Russia, e-mail: larisa.a.nazarova@mail.ru, ORCID ID: 0000-0002-3712-2939,
¹ Novosibirsk State University, 630090, Novosibirsk, Russia.

L.A. Nazarov, e-mail: mining1957@mail.ru.

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