Study On Oil-gas Two-Phase Flow Productivity Prediction Method And Inflow Performance Characteristics In Horizontal Well

With the progress of drilling technology, more and more horizontal well is applied in the oil and gas field development. Study on oil-gas two phase productivity prediction and inflow performance characteristics in horizontal well provide basis for the selection of oil production method and the optimization of well bore parameters.Based on mass conservation and Darcy law, oil-gas two phase three-dimensional percolation model in reservoir is established; And pressure drop model of oil-gas two phase variable mass flow in well bore is derived according to conservation of mass and momentum in the well bore, the hydrodynamic characteristic of two phase flow in horizontal wellbore is described using Drift-Flux model. These two models above are coupled by preserving the continuity of pressure and mass balance at sandface. Law of horizontal well productivity is derived by Newton-Raphson method after space and time discretization of the coupled model, which is the basis for optimization of wellbore geometric and completion parameters of horizontal well.For the solution gas drive reservoir, considering the impact of reservoir fluid properties(PVT properties of reservoir fluid,oil-gas relative permeability and bubble point pressure),reservoir properties(absolute permeability,reservoir thickness,drainage area and porosity) and the nature of horizontal wellbore(wellbore roughness,well length,well diameter,well location and skin factor) on inflow performance characteristics in horizontal well, this paper establishes 51 cases through the utilization of multi-segment well model in Eclipse reservoir simulation software, which take account of variable mass flow in wellbore on inflow performance of wells. Based on Vogel's dimensionless IPR curve method, this dissertation handles with IPR curve of all of the models. While a large quantity of nonlinear regression fitting are done by origin software. According to the previous correlations of IPR curve, this paper presents a new style dimensionless IPR curve regardless of different degrees of reservoir depletion, which predicts the inflow performance of horizontal well more quickly and conveniently.