A two-dimensional coupled hydromechanical discontinuum model for simulating rock hydraulic fracturing

• Published in: International journal for numerical and analytical methods in geomechanics Vol. 39; no. 5; pp. 457 - 481
• Main Authors: Jiao, Yu-Yong, Zhang, Huan-Qiang, Zhang, Xiu-Li, Li, Hai-Bo, Jiang, Qing-Hui
• Format: Journal Article
• Language: English
• Published: Bognor Regis Blackwell Publishing Ltd 10.04.2015; Wiley Subscription Services, Inc
• Subjects: Blocking; Computer simulation; DDARF; Deformation; discontinuum-based model; Fluid mechanics; Fracture mechanics; Hydraulic fracturing; hydromechanical coupling; Joining; Mathematical models; Rock; Rocks; Two dimensional
• ISSN: 0363-9061; 1096-9853
• DOI: 10.1002/nag.2314

Summary Within the framework of our discontinuous deformation analysis for rock failure algorithm, this paper presents a two‐dimensional coupled hydromechanical discontinuum model for simulating the rock hydraulic fracturing process. In the proposed approach, based on the generated joint network, the calculation of fluid mechanics is performed first to obtain the seepage pressure near the tips of existing cracks, and then the fluid pressure is treated as linearly distributed loads on corresponding block boundaries. The contribution of the hydraulic pressure to the initiation/propagation of the cracks is considered by adding the components of these blocks into the force matrix of the global equilibrium equation. Finally, failure criteria are applied at the crack tips to determine the occurrence of cracking events. Several verification examples are simulated, and the results show that this newly proposed numerical model can simulate the hydraulic fracturing process correctly and effectively. Although the numerical and experimental verifications focus on one unique preexisting crack, because of the capability of discontinuous deformation analysis in simulating block‐like structures, the proposed approach is capable of modeling rock hydraulic fracturing processes. Copyright © 2014 John Wiley & Sons, Ltd.