NUMERICAL MODELING OF THE MECHANICAL BEHAVIOR OF PORO-ELASTIC-PLASTIC ARTIFICIAL MATERIALS IN THE PROCESS OF HYDRAULIC FRACTURING

Abstract

This paper presents the preparation and verification of a numerical model of the porous-elastic-plastic behavior of artificial material which is used for carrying out the laboratory modeling of hydraulic fracturing (HF). The developed numerical model is consistent with the results of laboratory experiments on hydraulic fracturing conducted earlier at Sadovsky Institute of Geosphere Dynamics of the Russian Academy of Sciences. The numerical modeling is performed to determine the opening and shape of HF fractures in porous-elastic-plastic artificial materials. For this purpose, the filtration-capacitive and elastic-plastic properties of the studied medium are taken into account in the work. A mathematical model consisting of a system of defining equations and a failure criterion, initial and boundary conditions are described, and the results of numerical modeling using the finite element method are presented. A three-dimensional numerical porous-elastic-plastic model of the rock was constructed based on the geometry of the sample. As a result of numerical modeling, distributions of equivalent plastic deformations, fields of pore pressure and stress changes were obtained, and the opening, shape and propagation velocities of HF fractures during their growth were determined for porous-elastic and porous-elastic-plastic models.