Modeling Simultaneous Multiple Fracturing Using the Combined Finite-Discrete Element Method

Abstract EN

Simultaneous multiple fracturing is a key technology to facilitate the production of shale oil/gas.

When multiple hydraulic fractures propagate simultaneously, there is an interaction effect among these propagating hydraulic fractures, known as the stress-shadow effect, which has a significant impact on the fracture geometry.

Understanding and controlling the propagation of simultaneous multiple hydraulic fractures and the interaction effects between multiple fractures are critical to optimizing oil/gas production.

In this paper, the FDEM simulator and a fluid simulator are linked, named FDEM-Fluid, to handle hydromechanical-fracture coupling problems and investigate the simultaneous multiple hydraulic fracturing mechanism.

The fractures propagation and the deformation of solid phase are solved by FDEM; meanwhile the fluid flow in the fractures is modeled using the principle of parallel-plate flow model.

Several tests are carried out to validate the application of FDEM-Fluid in hydraulic fracturing simulation.

Then, this FDEM-Fluid is used to investigate simultaneous multiple fractures treatment.

Fractures repel each other when multiple fractures propagate from a single horizontal well, while the nearby fractures in different horizontal wells attract each other when multiple fractures propagate from multiple parallel horizontal wells.

The in situ stress also has a significant impact on the fracture geometry.