Production distribution in multi-cluster fractured horizontal wells accounting for stress interference

Key words:  horizontal wells  multi-cluster fracturing  stress interference  fracture propagation  productivity prediction

Abstract:

In order to investigate the production distribution in multi-cluster fractured horizontal wells in consideration of stress interference, numerical simulation has been conducted in combination of multi-cluster fracture propagation and production calculation models. Firstly, a mathematical model of multi-cluster fracture propagation was established based on a displacement discontinuity method and the algorithm of the model was solved by the Newton iteration method. Secondly, based on the potential theory and superposition principle, the calculation method of productivity was proposed by discretizing the fractures into elements under two scenarios with infinite fracture conductivity and finite conductivity. The results of a case study show that, when multi-cluster fractures propagate simultaneously, the effect of the stress interference not only affect the path of the fracture propagation but also influences the fracture 's geometry. However, the effect of the stress interference is beneficial for improving the well production. The well production is related to the fracture spacing and fracture half length, and the effect of the former is stronger than that of the latter. The predicted production with consideration of a variable conductivity of fractures is lower than that when considering a constant conductivity. The results show that the proposed method can be used to calculate the productivity distribution with any fracture configuration, which is more consistent with the actual situation.