Method of experimental determination of deformation and flow characteristics in rocks with regular block structure

The method of evaluation of deformation and flow characteristics in rocks with quasi-regular structure is developed and tested on a laboratory scale. The method uses the idea of physical averaging and testing of samples composed of twin structural components. Using an original technology and a manmade geomaterial (mixture of calibrated sand and cryogel at a ratio of 7 : 3), the plates 10×7×1 cm and cylinders (diameter 3 cm, height 6 cm) were manufactured. The cylinders were tested using standard procedures, and the characteristics of the manmade geomaterial were determined: the Young modulus Е=370 MPa, the uniaxial compression strength, the permeability km=8.4 darcy. The plates in number of 6 were used to make a layered sample with five discontinuities; the sample was subjected to stepped loading (s(n)–stress) applied in orthogonal direction to the discontinuities. From the measured contraction of the sample at the known E, the empirical constants were found for the two-parametric homographic function describing the discontinuity convergence and opening d versus s. Then, the side surface of the sample was isolated, the sample was placed in a sealed cell and subjected to the same program stepped loading. At each loading step n, the stationary flow tests were carried out, and the gas flow rate Qni was recorded at the present inlet pressure Pi . The geomechanical model of the experiment was built, and using the obtained analytical solution, the test data interpretation was undertaken: at the known values of d and km, and the measured Qni, the discontinuity permeability kf was calculated at each value of s. The empirical dependences of kf (d) and kf (s) were found.

Nazarov L. A., Golikov N. A., Skulkin A. A., Nazarova L. A. Method of experimental determination of deformation and flow characteristics in rocks with regular block structure. MIAB. Mining Inf. Anal. Bull. 2023;(11):70-81. [In Russ]. DOI: 10.25018/0236_1493_ 2023_11_0_70.

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 Siberian Branch of 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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