Fracability, the capability of shale that can be fractured effectively, is the most critical evaluation parameters in shale gas production. At present, it is generally recognized that using mineral composition and rock mechanics parameters to represent shale fracability is difficult to fully reflect the comprehensive properties of shale in hydraulic fracturing. However, so far all fracturing research about shale gas is almost considering marine shale and the understanding of shale fracability is confined and trapped within marine shale. Since shallow deposit of sedimentary strata in China is non-marine (lacustrine) facies sediments, China pay increasing attention to non-marine shale, which is opposite to the situation in Europe, and with the deepening of shale gas exploration, Europe will focus more on the non-marine shale in following decades. Due to the fact that lacustrine shale deposits differ from marine deposits in sedimentary environment, the former are always with frequent sand and mud interbed, interlayers development. Therefore, the influence factors of fracability in non-marine shale seemed more complexes and the research of shale fracability becomes more significant.

After general contrastive study of sedimentary environment, gas generation, mineralogy and physical properties of non-marine and marine shale based on literature data, this paper separately analysed the fracability influence factors (including sedimentary environment, mineral composition, diagenesis, brittleness, nature fracture, etc.) of non-marine shale focused on the Mesozoic Triassic Yanchang Formation shale in Ordos Basin of China. Moreover, comprehensive consideration of all above influence factors and statement of some fracability evaluation methods have been implemented. Unified and quantitative evaluation of fracability influence factors in non-marine and marine shale has been discussed afterwards. The summary of main influence factors of fracability in non-marine shale not only improved the shale fracability research, but also could guide the hydraulic fracturing practice.

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