Selecting a good fracturing candidate that can maximize the complex fracture network in advance isbeneficial for enhancing the fracturing effectiveness and the economic development of shale gas reservoirs.Brittleness is generally used to evaluate the capability of complex fracture networks by using criticalmechanical parameters,but these parameters must be acquired from well logs and time-consuming triaxialcore-scale mechanical tests.However,considering the physical and chemical instability of shales,standard-sized core plugs are difficult to obtain in some zones of interest.Thus,the analysis of drill cuttings bythe combination of SEM/EDS (scanning electron microscopy-energy dispersive spectrometer)analyses andgrid nanoindentation was used to replace conventional standard measurements on high-quality sized cores.A significant advantage of this technique is that drill cuttings can be collected from most wells.Furthermore,in contrast to traditional tests,the petrophysical and mechanical properties of shales can be characterizedsimultaneously.Thus,a comprehensive brittleness model can be established based on the mineral brittlenessand mechanical brittleness.Experimental results demonstrate that the integration of grid nanoindentationand the deconvolution technique can provide reliable estimations of the homogenized Young's modulus andPoisson's ratio,while EDS mapping can provide accurate mineral compositions of the indentation area.Themethod is successfully applied to evaluate the brittleness of a shale gas well in a shale gas field in China,which demonstrates that this method is a fast and cost-efficient way to evaluate the brittleness of shale gasformations with a small volume of rock samples.
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