Numerical simulation of complex fracture growth during tight reservoir stimulation by hydraulic fracturing

Abstract

The success or failure of hydraulic fracturing technology is largely dependent on the design of fracture configurations and optimization of treatments compatible with the in-situ conditions in a given reservoir. The petroleum industry continues to face challenges with this technology in the field, such as premature screen-outs, high treating pressures, complexities with multiple fractures propagation, complex fracture propagation from the deviated wellbore, etc. As these challenges persist better understanding of hydraulic fracture behavior for various reservoir conditions is still an important topic for research. Since the mechanism of hydraulic fracture growth involves the rock stress field and fluid flow field, the modeling work of fracture growth requires the treatment of coupled fluid flow and structural deformation phenomena. In this context, this paper briefly, summarizes an existing numerical tool for fracture growth analysis based on coupled fluid flow and structural deformation phenomena. Solid models have been developed to simulate different field conditions and then solved by using this numerical tool. The field conditions include different stress regimes, fracture geometry and fracture and well orientations. Results for different conditions have been presented and discussed to provide guide lines for better planning and design of hydraulic fracturing. The key finding is that if the well orientation and fracture configuration are not compatible with the in-situ stresses, complex fracture growth diminishes the likelihood of success and exhibits some of the above mentioned symptoms during treatments in the field.