Impact of the crack direction in a multistage hydraulic fracturing on the oil recovery factor

The analytical expressions for normalization of the actual data on the well operation initial parameters are presented. The results of the dimensionless production index comparison are transferred to a mathematical model of the field sector in order to select an effective direction of the wellbore horizontal section. To determine an optimal production strategy, a synthetic model was developed using the tNavigator program. The Local Grid Refinement (LGR) method was applied to provide an accuracy of the mathematical model of a multistage hydraulic fracturing (MSHF) problem. This method represents a local grinding of the cells in the region of the MSHF cracks' formation. The grinding was carried out up to 4 mm in a cell size. A virtual perforation method was used for the rest of production wells in the sector. The models characterized by various permeability were calculated, and the following results were obtained: accumulated oil production in a longitudinal orientation of the MSHF cracks is higher than that in the transverse cracks, which is irrespective of the permeability. The initial oil production rate from a transverse crack location is higher, therefore, the pressure drop occurs much faster resulting in a low-pressure area formation. Such a crack arrangement in the well leads to a rapid decline of well and provides an increase in the water production.