Analysis of Factors Influencing the Production Profile Equilibrium for Perforated Horizontal Wells

The equilibrium of production profile,which reflects the equilibrium of producing degree,is an important basis for perforation optimization.Combining source function with skin-factor model,a reservoir-wellbore coupled model of perforated horizontal wells in anisotropic reservoirs is established based on the principle of potential superposition.The model takes the influence of formation damage and perforation on flowing performance of horizontal wells into account.The solution procedures for production profile and potential distribution profile are also presented.In this paper,the influence of well inclination,formation thickness,oil viscosity and vertical permeability on the equilibrium of production profile for perforated horizontal wells are investigated.Affected by flow regime,drainage area difference and wellbore pressure drop,the inflow profile of perforated horizontal wells shows end effect and difference between heel and toe,and producing profile shows skewed U shape.The end effects decrease with the decrease of well inclination and vertical permeability,but increase with the decrease of reservoir thickness and oil viscosity.The flow difference between heel and toe decreases with the decrease of well inclination,reservoir thickness and vertical permeability,but increases with the decrease of oil viscosity.