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In situ X-ray micro-CT for investigation of damage evolution in black shale under uniaxial compression

  • Y. Wang
  • Z. Q. Hou
  • Y. Z. Hu
Original Article
  • 34 Downloads

Abstract

Crack damage evolution of shale is crucial to the hydraulic fracturing treatment and engineering stability. Although many effects have been done on the macroscopic characteristics of shale, yet the microscopic failure mechanism is not well understood. A uniaxial compressive test on black shale was conducted under topographic monitoring using in situ X-ray micro-tomography (µCT). A series of high-resolution reconstruction images were obtained by carrying out CT scans at six key points throughout the test to obtain the internal structure of shale sample. In addition, the CT values for the purpose of crack damage evolution in shale were identified. Clear 2D/3D CT images, CT value analysis and image segmentation analysis reveal that the sample experiences compression, damage, cracking, crack propagation, and collapse stages. Crack geometry and distribution in the shale sample is visualized by rendered CT images, and a combined tension and shear failure mode is observed from the fracture rose diagram. This work suggests that formation and propagation of fractures are influenced by the stratified structure and weak cementation medium between layers.

Keywords

Black shale Micro-tomography CT Damage evolution Failure morphology 

Notes

Acknowledgements

The authors would like to thank the editors and the anonymous reviewers for their helpful and constructive comments. This work was supported by the National key technologies Research & Development program (2018YFC0808402), the Fundamental Research Funds for the Central Universities (2302017FRF-TP-17-027A1), and the National Natural Science Foundation of China (Grants Nos. 41502294).

Compliance with ethical standards

Conflict of interest

The authors declare no conflict of interest.

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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Beijing Key Laboratory of Urban Underground Space Engineering, Key Laboratory of Ministry of Education for High-Efficient Mining and Safety of Metal, Department of Civil Engineering, School of Civil and Resource EngineeringUniversity of Science and Technology BeijingBeijingChina
  2. 2.Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and GeophysicsChinese Academy of SciencesBeijingChina

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