Second fracturing operation (re-fracturing) is often used in producing wells to improve well productivity that reduces with time. In some cases well rate/pressure performance analysis indicates a significant improvement of well productivity after re-fracturing. A change of a fracture orientation (re-orientation) while re-fracturing is one of possible reasons of productivity improvement. It is important to find a method to predict the second fracture direction and to find conditions of new fracture creation. This method would help one to select appropriate wells for re-fracturing. This paper discusses two cases of numerical modeling of well rate and pressure performance for pre- and post-refracturing time periods. Case one is when properties of the "old" fracture improved. Case two is when fracture re-orientation occurs after hydraulic fracturing operation, i.e., when the two (the "old" one and the "new" one) perpendicular fractures occur. Using results of numerical modeling, it is possible to estimate the contribution of both these two cases to the well inflow. Further, the production pressure analysis for re-fractured wells was made using field data and conclusions about hydraulic fracture re-orientation were made. The occurrence of fracture re-orientation in all considered examples was checked using the RN-KIN geomechanical simulation software. Also the sensitivity analysis for various reservoir parameters was performed in order to understand the limits of the fracture re-orientation technology. This analysis allowed us to identify individual sections of the field and wells in pattern elements where fracture re-orientation after re-fracturing is most probable.
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