Effects of spatial heterogeneity and material anisotropy on the fracture pattern and macroscopic effective toughness of Mancos Shale in Brazilian tests
Abstract
For assessing energy-related activities in the subsurface, it is important to investigate the impact of the spatial variability and anisotropy on the geomechanical behavior of shale. The Brazilian test, an indirect tensile-splitting method, is performed in this work, and the evolution of strain field is obtained using digital image correlation. Experimental results show the significant impact of local heterogeneity and lamination on the crack pattern characteristics. For numerical simulations, a phase field method is used to simulate the brittle fracture behavior under various Brazilian test conditions. In this study, shale is assumed to consist of two constituents including the stiff and soft layers to which the same toughness but different elastic moduliare assigned. Microstructural heterogeneity is simplified to represent mesoscale (e.g., millimeter scale)features such as layer orientation, thickness, volume fraction, and defects. The effect of these structural attributes on the onset, propagation, and coalescence of cracks is explored.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 19, 2017
- Accession Number
- AD1077961
Entities
People
- Hongkyu Yoon
- Mathew Duffy Ingraham
- SeonHong Na
- WaiChing Sun
Organizations
- Columbia University