Hossein Jalalifar
Professor, Shahid Bahonar University of Kerman, Iran
Title: Numerical Modelling of Hydraulic Fracturing Using XFEM: Analysis of Interaction of First Crack Direction and In Situ Stress Field
Biography
Biography: Hossein Jalalifar
Abstract
In recent years, hydraulic fracturing is such a method, which was used in oil and gas wells to enhance recovery in low permeability reservoirs. In hydraulic fracturing operation, the fluid with high pressure is injected into the well that had been isolated by packers.
The prediction of fracture direction is one of the main challenges of hydraulic fracturing operation. A numerical method recently has been developed for simulation of crack propagation named the extended finite element method (XFEM). In this method, the nodes surrounding the cracks are enriched through special functions. Accordingly, for such nodes, the degrees of freedom are increased, which results in greater displacement around each crack. In this paper, a XFEM code was developed to simulate the hydraulic fracturing problem. In order to validate of the developed Code, the results are compared with some two-dimensional analytical solutions and confirmed by its correctness. The results showed that, in the case where the initial crack is in direction of the maximum main stress (σ1), the crack is propagated in its direction (perpendicular to the minimum main stress, σ3). But when the initial crack is not in direction of the maximum stress, the crack propagates in that direction and with increasing from the well axis it returns to the maximum main stress direction.