Study On The Parameter Optimization Design Method Of Gas Condensate Well Production System

Gas condensate reservior's phase state alter complicatedly and fluid composition change with pressure because of the usual abnormal condensate phenomenon during the exploitation process, so that the flow description of liquid in the wellbore and parameter optimization design of the production system are more complicated than that of common gas reservoir and oil reservoir. Based on systemic research, establishing a gas-liquid two-phase equilibrium model, giving the calculated ways of the model. It is the basic theory of phase equilibrium in parameter optimization design method of gas condensate well production system which considering phase behavior of gas and liquid; Based on the theory of phase equilibrium and equation of state, deviding the gas condensate system into three zones from gas feed boundary to wellbore, obtainning the boundary pressure of every zone by saturation distribution of condensate oil, and defining the concept of pseudopressure, establishing a condensate well inflow performance model which considering phase behavior, three zone seepage, condensate liquid and gas phase non-darcy flow.giving the calculated ways of model; According to law of mass conservation, momentum conservation and energy conservation, considering phase state of different temperature and pressure, establishing a gradient equation of pressure, temperature, flow velocity and density along gas condensate wellbore, obtainning the distribution of pressure,temperature, flow velocity and density along the wellbore by fourth order runge-kuta method, making sensitivity analysis of different productions; Comparing the two common liquid withdrawal model——Turner model and Limin liquid withdrawal model according to case history, calculating the critical flow velocity and critical flow rate by the two models, optimizing the optimum gas well liquid withdrawal model; Establishing a comprehensive parameter optimization design method of gas condensate well production system by combining phase equilibrium model, inflow performance model, wellbore flow model and wellbore liquid withdrawal model. And making a corresponded program of gas condensate well parameter optimization design method which can instruct the development of gas condensate reservoir better.