Modeling fracture initiation and propagation from a pressurized hole: A dislocation-based approach

This paper presents an approach to analyze the breakdown process of a pressurized circular cavity. Such a process is associated with the initiation and propagation of two radial symmetric tensile fractures. This problem is solved semi-analytically by making use of the exact elastic solution of a finite dislocation, which satisfies homogeneous boundary conditions at the circular cavity and at infinity. This approach leads to the formulation of a singular integral equation which is solved numerically using Erdogan and Gupta (1972) method. Application of this method to the analysis of the breakdown pressure in a hydraulic fracturing stress test is then described and the influence of the far-field stress, pressurization rate, and size of the borehole on the wellbore pressure response is discussed.