The Study of Fracturing Rock Body Damage and Cracks Propagation Model Basing on Catastrophe Theory

It is vital for the study of fracturing parameters optimal design and fluids rate forecast to calculate fracture propagation parameters accurately. In order to calculate fracture propagation accurately, in this paper, the model for calculating the value of energy release when the rock body collapses was established basing on catastrophe theory, considering that the collapse of fracturing rock body was caused by the accumulation of rock body deformation energy and releasing suddenly. And making the assumption that the energy that had released can be used for the propagation and extension of the cracks, the new model for calculating the parameters of cracks were established. The characteristics of sandstone rock mass were selected to study and analyze the fracturing parameters through laboratory experiment in daqing oilfield, the results show the maximum error between theoretical and the actual result is 9.71%. The new method that was put forward this paper has important academic value to study fracturing propagation.