Estimating Leak-Off Characteristics Due to Hydraulic Fracture and Natural Fracture Interaction Utilizing XFEM-Based 3D Hydraulic Fracture Model

Abstract

Leak-off characteristics during hydraulic fracturing operation are difficult to determine but yet critical in developing conventional and unconventional reservoirs with natural fractures and other weak structural planes (e.g. micro-faults, weak beddings). When hydraulic fractures interact with natural fractures, they will either be arrested or transect the natural fractures depend on the leak-off characteristic of the natural fractures. The effective leak-off characteristic in a naturally fractured reservoir is an essential input for hydraulic fracturing simulation and consequent completion design as well as reservoir simulation (e.g., dual porosity and dual permeability) and consequent production optimization. A novel method of estimating the effective leak-off characteristic in a naturally fractured reservoir is developed directly from hydraulic fracturing diagnostic tests such as minifrac and DFIT utilizing eXtended Finite Element Method (XFEM)-based 3D hydraulic fracturing model. Complex behaviors of hydraulic fractures interacting with natural fractures are simulated in the XFEM-based hydraulic fracturing model and history-matched with minifrac/DFIT data (i.e., treating pressure), in order to estimate effective leak-off characteristics of naturally fractured reservoirs.