One CT imaging method of fracture intervention in rock hydraulic fracturing test

Up to now, the theory and technology of detection of sub-millimeter hydraulic fracturing cracks in large scale rock samples is the key problems of hydraulic fracturing test. According to the principle of substance X-ray absorption and attenuation, three kinds of nanometer CT imaging interventional enhancer based on the gold, mercury and bismuth were proposed. The samples of the hydraulic fracturing and the samples added in the interventional treatment were scanned individually by industrial X - ray CT. By comparing 3 kinds of interventional treatment before and after the treatment of cracks imaging effect, the following conclusions can be obtained: The imaging effect of hydraulic fracture in rock is enhanced by using the interventional enhancer, which is mainly reflected in the gray contrast and resolution of the enhanced X-ray CT imaging; the effect of nano-gold and nano-bismuth on the fracture imaging is the best; nano-bismuth intervention enhancer can detect the cracks width of 0.2 mm, and the capacity of nano-gold intervention enhancer to identify the minimum cracks width increased by 18.75%, however the resolution of the nano mercury intervention is not obvious; nano-scale high atomic number materials can be used as a cracks intervention to improve the imaging resolution of micro cracks in rock fracturing.