Simulating the Single- and Multi-Stage Hydraulic Fracturing: Some Insights Gleaned from Discontinuum and Continuum Modelling

Abstract Discontinuum and continuum modelling approaches were used to simulate the single- and multi-stage hydraulic fracturing. Two-dimensional discontinuum modelling of single-stage fracturing revealed a marked modification of the stress field in the vicinity of the fracture (stress shadow effect) during fracture propagation which was identified as the reason for the significant asymmetry of fracture propagation about the wellbore observed for multi-stage fracturing. Allowing the fracturing fluid to flow back after each fracturing stage appeared to minimize this stress shadow effect on fracture propagation geometry. Three-dimensional discontinuum modelling results showed similar behaviors as two-dimensional modelling. Inclined orientation of wellbores with respect to principal stresses and enabling fluid backflow after each fracturing stage were found to be effective to minimize the stress shadow effect on fracture propagation geometry after three-dimensional discontinuum modelling. Our three-dimensional continuum modelling of hydraulic fracture propagation so far revealed some promising results demonstrating its capability to simulate hydraulic fracturing applications. Finally, the specific and contrasting features of both approaches are discussed here giving some useful insights into both approaches to assist users with choosing the appropriate method for a particular simulation project.