Production Capacity Prediction Of A Water-loading Gas Well

In the process of water bearing gas field development,gas well of water-loading is an inevitable and common phenomenon in gas Wells at the middle and later stages of gas field development.Therefore,it is a great practical significance to reasonably and accurately predict the productivity of gas Wells with fluid accumulation and to simulate the variation law of gas well fluid accumulation.Bottom-water gas reservoir exists widely in oil and gas fields at home and abroad,and they are widely distributed.If not properly developed,it can lead to rapid bottom water coning,resulting in fluid accumulation in gas wells,or even gas wells completely crushed.Wellbore fluid accumulation process is the result of coupling action of gas reservoir and wellbore,so the productivity of gas well should be studied from two aspects.First,the bottom water coning productivity model is established to simulate the productivity change rule of gas wells in water-bearing gas reservoirs.Second,the wellbore pressure drop model is established to analyze the fluid carrying capacity of gas Wells and to simulate the change rule of the fluid carrying process.In this paper,domestic and foreign literature on bottom water coning formation process and reservoir water coning model are investigated deeply.Based on the principle of energy conservation,the energy distribution of each part in the accumulative gas well is studied.According to the gas-liquid characteristics,the wellbore pressure drop model of the accumulative gas well is established to analyze the fluid carrying capacity of the gas well,predict the variation law of fluid carrying capacity of the gas well,and then couple the gas reservoir with the wellbore to establish the productivity prediction model of the accumulative gas well in bottom water gas reservoir.This model can not only dynamically predict the productivity of liquid-accumulated gas Wells,but also accurately predict the shutdown time of liquid-accumulated gas Wells and provide theoretical basis for timely drainage of gas Wells.Based on the productivity prediction model of liquid-accumulated gas Wells,this paper also carries out optimization design aiming at maximum accumulative gas production,providing theoretical guidance for actual production.