To apply image processing technique into rock fracture recognition, the key and hardest task is to auto-sewing fractures on the the rock fracture images, and the newly developed rock fracture sewing algorithm is very effective for sewing rock fractures, it has been tested in a laboratory and works satisfactorily.

According to the basic principle of crystallography, this paper discusses the genesis of healed cracks in natural quartz and the significance of its identification.

Considering the heat exchange between the fracture fluid and the rocks occurred in closure process and by means of building up hydraulic fracture temperature field model,the change of temperature field during the fracture closure process has been figured out and combined with the experiment data of that the temperature affects the fluid flowage .

Firstly, according to theory of fluid flow in porous media, mechanism of leakoff of fracturing fluid during fracture closure was analyzed and a 2D dynamic leakoff model of non-Newtonian fracturing fluid was estab.