3D microscopic CT imaging and significance of SK-2 deep mudstone of Shahezi Group

In order to deepen the understanding of the vertical change rule of the deep shale gas in the Songke 2 Well, the authors selected the 3500~5700 m section of the Shahezi Formation to carry out the X-ray 3D Computed Tomography (CT) imaging experiment.X-ray CT scan was performed on 19 pieces of 2 cm-diameter columnar cores to obtain non-destructive core scan data, and a three-dimensional image spatial structure with a core resolution of up to 15 μm was established.The pore morphology structure and space of the reconstructed core pore model were analyzed by comparative study of spatial distribution and coordination number, statistics of the vertical distribution of sample porosity and connectivity.This experiment proves that the digital core data have high resolution and rich information.The gray value information reflects different components in the sample.The skeleton and minerals are high gray values, and the pores and cracks are low gray values.Studies have shown that areas with large equivalent pore diameters have high porosity, and areas with large coordination numbers have good connectivity.The vertical distribution of porosity and connectivity is consistent with traditional knowledge and can be verified with logging information.It is believed that the digital core can be used as an important auxiliary method for deep core research in the future.