Shale gas reservoir is tight with very low permeability. In order to commercially develop shale gas, hydraulic fracturing is essential to improve the permeability. Evaluation of the brittleness index for shale gas is significant in choosing the available zone for hydraulic fracturing. In this paper, multi-scale micromechanics model (Mori-Tanaka) is used to calculate the effective elastic parameter for the evaluation of the brittleness index Ba. Then Ba is compared with the brittleness index Ba_d and Bm, which are based on the dynamic mechanical parameters and mineral content, respectively. Finally, Partial least squares regression (PLS) is used to study the relationship between Ba and mineral components. Results show that Bm increases from the top to the bottom of the interval. Besides, Ba has the same trend with Bm, but Ba_d does not. Compared with Bm, Ba can highlight the ductile and brittle areas, which makes the evaluation of brittleness index effective. Analysis shows that only Quartz and pyrite have positive correlation with Ba among all minerals. Quartz and clay mineral are the most important factors to increase and reduce the brittleness index of shale, respectively.


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  1. Chnstensen, R. M. and Zywicz, E. A.
    [1990] Three-dimensional constitutive theory for fiber composite laminated media: Journal of Applied Mechanics, 57, 948–955.
    [Google Scholar]
  2. Gneser, B. and Bray, J.
    [2007] Identification of production potential in unconventional reservoirs. Presented at SPE Annual Technical Conference and Exhibition
    [Google Scholar]
  3. Jin, X., Shah, S. N, Roegiers, J. C. and Zhang, B.
    [2014] Fracability evaluation in shale reservoirs-an integrated petrophysics and geomechanics approach. Presented at SPE Hydraulic Fractunng Technology Conference in Woodlands.
    [Google Scholar]
  4. KlusemannB., BohmH.J., SvendsenB.
    [2012] Homogenisation methods for multi-phase elastic composites with non-elliptical reinforcements: compansons and benchmarks. European Journal of Mechanics -A/Solids, 34, 21–37.
    [Google Scholar]
  5. MonfaredS. and UlmF.-J.
    [2016] A molecular informed poroelastic model for organic-nch, naturally occurring porous geocomposites. Journal of the Mechanics and Physics of Solids, 88, 186–203.
    [Google Scholar]
  6. OrtegaJ.A., UlmF.-J. and AbousleimanY.
    [2007] The effect of the nanogranular nature of shale on their poroelastic behaviour. Acta Geotechnica, 2, 155–182.
    [Google Scholar]
  7. Rickman, R, Mullen, M.J., Petre, J.E., Gneser, W.V. and Kundert, D.
    [2008] A practical use of shale petrophysics for stimulation design optimization: all shale plays are not clones of the Barnett Shale. Presented at SPE Annual Technical Conference and Exhibition.
    [Google Scholar]
  8. RybackiE., MeierT. and DresenG
    [2016] What controls the mechanical properties of shale rocks? – Part II: Bnttleness. Journal of Petroleum Science and Engineering, 144(2016), 39–58.
    [Google Scholar]
  9. Zaoui, A.
    , 2002. Continuum micromechanics: survey. Journal of Engineering Mechanics, 128(8), 808–816.
    [Google Scholar]

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