Numerical simulation of simultaneous multiple fractures initiation in unconventional reservoirs through injection control of horizontal well

Abstract

Simultaneous fracturing stimulations in horizontal well are effective tools for promoting productivity of unconventional reservoirs. However, fracture lengths and widths of some perforation clusters may be restricted due to the stress shadow effects. In this paper, a numerical model to simulate nonplanar fractures simultaneous initiation in porous media is established based on the extended finite element method (XFEM). The amount of fluid flowing into each fracture is dynamically calculated with a total injection volume in this model. Sensitivity studies of formation parameters on fractures geometry of simultaneous fracturing are presented. The in-situ stress contrast is found to be the main factor controlling the fractures propagation. The initiation of interior fracture will be restricted or compressed to be closed in the vicinity of the injection point. The influence of injection rate and perforation friction on fractures initiation is investigated. Strategies to optimize fractures geometry are presented through injection control of each fracture. The method presented in this paper can be used in horizontal well design to achieve reasonable fractures geometry.