scholarly journals Simulation of the interactions between multiple hydraulic fractures and natural fracture network based on Discrete Element Method numerical modeling

2020 ◽  
Vol 8 (8) ◽  
pp. 2922-2937 ◽  
Author(s):  
Yumei Li
2020 ◽  
Vol 28 (2) ◽  
pp. 1-7
Author(s):  
Rouhollah Basirat ◽  
Jafar Khademi Hamidi

AbstractUnderstanding the brittleness of rock has a crucial importance in rock engineering applications such as the mechanical excavation of rock. In this study, numerical modeling of a punch penetration test is performed using the Discrete Element Method (DEM). The Peak Strength Index (PSI) as a function of the brittleness index was calculated using the axial load and a penetration graph obtained from numerical models. In the first step, the numerical model was verified by experimental results. The results obtained from the numerical modeling showed a good agreement with those obtained from the experimental tests. The propagation path was also simulated using Voronoi meshing. The fracture was created under the indenter in the first step, and then radial fractures were propagated. The effects of confining pressure and strength parameters on the PSI were subsequently investigated. The numerical results showed that the PSI increases with enhancing the confining pressure and the strength parameter of the rock, including cohesion and the friction angle. A new relationship between the strength parameters and PSI was also introduced based on two variable regressions of the numerical results.


Langmuir ◽  
2019 ◽  
Vol 35 (39) ◽  
pp. 12754-12764 ◽  
Author(s):  
Alexandr Zubov ◽  
José Francisco Wilson ◽  
Martin Kroupa ◽  
Miroslav Šoóš ◽  
Juraj Kosek

2020 ◽  
Vol 205 ◽  
pp. 08001
Author(s):  
Shahrzad Roshankhah ◽  
Arman K. Nejad ◽  
Orlando Teran ◽  
Kami Mohammadi

In this study, we present the results of two-dimensional numerical simulations for the effects of rock matrix permeability on the behaviour of hydraulic fractures in intact and pre-fractured rocks. The simulations are performed using the Finite-Discrete Element Method (FDEM). In this method, the deformation and fluid pressure fields within the porous rock blocks, pre-existing fracture network, and hydraulically induced fractures are calculated through a fully coupled hydromechanical scheme. Furthermore, new fractures can initiate in crack elements located between each pair of finite elements and can propagate in any path that the boundary and loading conditions require according to non-linear fracture mechanics criteria. Fluid channels are also defined between pairs of finite elements simulating the inter-connected flow paths through porous media. Four models of the rock mass are created in this study: (i) homogeneous-impermeable, (ii) homogeneous-permeable, (iii) heterogeneous-impermeable matrix, and (iv) heterogeneous-permeable matrix. Heterogeneous rock masses contain a discrete fracture network (natural fractures) in the rock mass structure. Hydraulic fracturing is modelled in domains of 40×40 m2 with the four different structures and mass transport capacities, and the results are compared to each other. The results highlight the significant effect of diffusive fluid flow through rock blocks, in addition to the flow through fracture network, on the global hydromechanical behaviour of the rock mass. These results help to understand the governing hydromechanical processes taking place in fractured rocks with matrix of different permeability, such as granites, shales, carbonate rocks, and sandstones and the extent of complexities required to model their behaviour to achieve reasonable accuracy.


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