Events

Speaker:  Dr. Armando Duarte, Professor and Excellence Faculty Scholar at the Department of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign (UIUC)

Title of Seminar: “Recent Developments in the Generalized Finite Element Method for Non-Planar 3-D Hydraulic Fractures” 

Abstract: Fracture initiation in Hydraulic Fracture (HF) treatments is controlled by perforation tunnels penetrating in the formation. The near wellbore reorientation of fractures towards the preferred fracture plane leads to complex fracture geometries which in turn induce a strong nonlinear pressure drop near the wellbore. Furthermore, fracture conductivity is substantially reduced by the fracture tortuosity which constricts the flow of the fracturing fluid as well as hydrocarbons through the fractures. Although the main causes for HF tortuosity in the near-wellbore region are now well recognized, detailed quantitative predictions of the complex 3-D HF geometry in the near-wellbore and its impact on fracturing pressures and screen-out risk remains an open problem. This presentation reports on recent advances of a Generalized Finite Element Method (GFEM) for non-planar 3-D hydraulic fractures and its implementation in ISET—An adaptive GFEM solver developed at the University of Illinois at Urbana-Champaign. Verification examples and several problems illustrating the application of ISET to the simulation of 3-D hydraulic fracture propagation are presented. They include the simulation of fracture re-orientation near a wellbore, the demonstration of the effect of fluid viscosity and in-situ stress on fracture path, and problems involving the interaction of 3-D non-planar fractures. We also show that the conditioning of GFEMs available in the literature may strongly depend on the location of discontinuities relative to element nodes, edges or faces. We present our work towards a GFEM that has a conditioning of the same order as the standard FEM while delivering significantly higher accuracy.

Biography:   Armando Duarte is a Professor and Excellence Faculty Scholar at the Department of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign (UIUC). He is affiliated with the UIUC Computational Science and Engineering Program, a Fellow of the United States Associate for Computational Mechanics, and a Fellow of National Center for Supercomputing Applications (NCSA). Armando Duarte holds a Ph.D. in Engineering Mechanics from The University of Texas at Austin. His research focuses on computational mechanics and Generalized Finite Element Methods with focus on computational fracture mechanics, multi-scale and multi-physics problems such as hydraulic fracture propagation and failure of structural connections. Dr. Duarte’s group has a history of collaborative research with industrial (ExxonMobil, GE) and national laboratory (AFRL, FAA-CEAT) partners.