Mahmoud Behnia - Assistant Professor, Mining Engineering Faculty, Isfahan University of Technology
Mohammad Fatehi Marji - Associate Professor, Mining and Metallurgical Department, Yazd University
Abolfazl Abdollahipour - PhD of Rock Mechanics, Research Institute of Petroleum Industry (RIPI)

In this research study, the hydraulic fracturing propagation in multi-layered media (stiff and soft) with different elastic properties is investigated. Therefore, boundary element method based on the displacement discontinuity formulation is presented to solve general problems of hydraulic fracturing propagation in layered formations. The crack tip element and a higher order boundary displacement collocation technique are used to increase the accuracy of the method (2DFPM) in modeling of non-homogenous media. The stress intensity factor and tensile stress near the crack tip under different elastic modulus are evaluated to study the hydraulic fracture propagation. Related to the position of the fracture with interface these factors have different values and finally, they control the fracture propagation. The results show that if the hydraulic fracture originates in the stiffer layer, its capability to cross the layer increases and is vice versa for the softer material. The comparison of the results gained from the numerical method with those in the literature show a good performance of the method in the case of propagation of hydraulic fracture in layered formations.

fracturing, layered formation, fracture propagation, Displacement discontinuity method