A comprehensive review of numerical simulation methods for hydraulic fracturing

Hydraulic fracturing unlocks previously inaccessible hydrocarbons in unconventional reservoirs by creating artificial pathways in the unconventional reservoir. Numerical simulation expands the scope of hydraulic fracturing design for various reservoir conditions. This review paper explores the synergy between numerical simulation and hydraulic fracturing modeling, focusing on critical elements like geomechanical behavior, geological conditions, and fluid dynamics. Analytical models in hydraulic fracturing design are discussed to underscore their foundational importance. The assumption of constant fracture height limits the application of Perkins-Kern-Nordgren model (PKN) and Kristianovich-Geertsma-de Klerk model (KGD). Radial models assume 3D flow but lack reliability in nonradial settings, and the Pseudo 3D model (P3D) shares PKN's assumptions with variable fracture height, sacrificing some details for efficiency. Planar 3D model (PL3D) enhances accuracy by discarding PKN's elastic response assumption but requires extended computation. Unconventional fracture model is effective for complex scenarios but relies on DFN modeling parameters for accuracy. The choice of numerical simulation method in hydraulic fracturing depends on the specific aspect studied, each with its strengths and limitations. For instance, boundary element methods are efficient for exterior problems, finite element modeling suits 3D nonplanar fractures, and the extended finite element method excels in hydraulic and natural fracture interactions. Peridynamics shows potential but needs further development for cost-effectiveness. PFC and UDEC/3DEC-based simulations can explore microscopic mechanisms. Combining these methods with other approaches provides a comprehensive study of realistic reservoir conditions. This review guides the selection of a suitable numerical simulation methodology based on the study's scope.