The Model for Calculating Pore Evaluation of Fractal Rock Body Under Hydraulic Fracturing

In general, the pore medium of rock has fractal characters. In order to calculate the change regulations of porosity and evaluation character of the rock under hydraulic fracturing accurately, in this paper, a new damage variable was defined to describe the change of porosity. The model for calculating pore evaluation of the fractal fracturing rock body was established according to the principle of conservation of energy, considering the strain energy, the cracks propagation energy and the gravitational potential energy of fracturing fluid in the process of fracturing. The change regulations of fracturing parameters were calculated combining with the reservoir pore characters of Xinmin region. The change characters of the porosity were simulated by ANSYS, and the rationality and advancement of the new model was determined by deliverability analysis. Key words : Fractal rock body; Pore characters; Deliverability calculation; Hydraulic fracturing