The workflow to analyze hydraulic fracture effect on hydraulic fractured horizontal well production in composite formation system

Hydraulic fracturing generally leads to highly complex hydraulic networks for tight oil reservoirs. It is significant to understand the hydraulic fracture effect on well performance. As an effective tool, semi-analytical solution for well pressure transient analysis (PTA) and rate transient analysis (RTA) is used in large amount because of higher calculation efficiency than numerical solution. In this paper, the PTA and RTA methods and result of composite formation system (CFS) are shown comprehensively. Firstly, a mathematical model of multistage fractured horizontal well (MsFHW) in CFS was proposed for tight oil reservoir with different regions and formation properties. In the model, two regions with different formation parameters were distinguished. This assumption of two regions, i.e. CFS is a composite tight reservoir formed after hydraulic fracturing. Difference of finite hydraulic fracture conductivity, inclined angle of hydraulic fracture, different shapes of multi-wing fractures in perforating point are considered to make this model powerful to analyze production performance of different MsFHW types. The inner and outer regions were assumed as dual porosity medium，but single porosity medium model can also be solved by simplification. Then, the solution of MsFHW performance analysis model is obtained by source function method and the source function superposition principle which are common used in PTA and RTA. PTA for well producing at a constant production rate and RTA for well producing at a constant wellbore pressure were obtained and discussed. Different flow regimes were divided for different fracture geometry situations. The effects of different MsFHW types on PTA and RTA were analyzed. The inflow performance for different hydraulic fractures were presented