Laboratory study on the mechanical behaviors of an anisotropic shale rock

Quan Gao, Junliang Tao, Jianying Hu, Xiong Yu

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Shale gas is becoming an important energy source worldwide. The geomechanical properties of shale rocks can have a major impact on the efficiency of shale gas exploration. This paper studied the mineralogical and mechanical characteristics of a typical gas shale in Ohio, USA. Scanning electron microscope (SEM) with energy dispersive X-ray (EDX) analyses was employed to measure the microstructure and material composition of the shale rock. The anisotropic behaviors of shale rock, including compressive and tensile strengths, were experimentally measured. The characteristics of shale rock were also studied by nondestructive wave speed measurements. The shale demonstrated strong anisotropic behaviors with the tensile strengths perpendicular to the bedding plane around 300e360 times of that parallel to bedding plane. Results of ultrasonic tests indicated that both compression and shear wave velocities show strong anisotropic patterns. The compression wave speed was the smallest in the direction perpendicular to the bedding plane; while the shear wave speed was the smallest in the direction parallel to the bedding plane. The ratio of wave speed anisotropy is around 1.3e1.4 for compression wave; the ratio of shear wave speed anisotropy is larger and more diverse compared with the compression wave anisotropy. This might be related to the larger variability in the frictional adhesive strength along bedding plane than the compressive adhesive strength.

Original languageEnglish (US)
Pages (from-to)213-219
Number of pages7
JournalJournal of Rock Mechanics and Geotechnical Engineering
Volume7
Issue number2
DOIs
StatePublished - Jan 1 2015
Externally publishedYes

Fingerprint

bedding plane
Shale
shale
Rocks
Shear waves
compression
S-wave
Anisotropy
anisotropy
rock
tensile strength
Adhesives
Tensile strength
compressive strength
Compressive strength
wave velocity
microstructure
Electron microscopes
Ultrasonics
laboratory

Keywords

  • Anisotropy
  • Compression wave
  • Shale rock
  • Shear wave

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology

Cite this

Laboratory study on the mechanical behaviors of an anisotropic shale rock. / Gao, Quan; Tao, Junliang; Hu, Jianying; Yu, Xiong.

In: Journal of Rock Mechanics and Geotechnical Engineering, Vol. 7, No. 2, 01.01.2015, p. 213-219.

Research output: Contribution to journalArticle

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