Mathematical model of artificial fracture reinitiation in vugs of carbonate reservoirs

Typically, oil and gas are stored in the vugs of fractured-vuggy carbonate reservoirs, and their production can only be effectively improved by enhancing the connection of vugs via cracking. However, owing to recent de-velopments in the field, a connection of more than one vug is required during fracturing work via an artificial fracture. Hence, it is necessary to develop a method that allows the propagation of fracture reinitiation from one vug to the next. However, fracture reinitiation in vugs is a difficult problem that is affected by the fluid injection, in-situ stress, and shape of the vug. Therefore, a mathematical model for fracture reinitiation in vugs was developed in this study. Subsequently, the shape of the vug was regularized and three types of stresses were considered: in-situ stress, fluid pressure inside the vugs, and fluid pressure from hydraulic fractures. Based on the results, this fracture reinitiation model can be used as a reference for fracturing studies in the field of fractured-vuggy carbonate formations.