Study On Mechanism Of Gas-Liquid-Solid Flow And Sand-Carrying Regularity Of Producing Water Gas Well

There are many unconsolidated sandstone gas reservoir in and out the country,and the change of crustal stress leads to the easiness of sanding out.If the formation sand could not be carry out to the ground immediately,it would gather together in the wellbore and the outcome would be severe.More importantly,water outlet is quite common in these loose sand gas reservoirs.If the bottom hole of gas well produced large amount of water because of natural or artificial reasons and it could not be exhausted from the wellbore in time,then there are chance that the gas well will be abandoned because of water logging in the bottom hole.Since then,the paper focuses on the problem of sand carrying in water-producing gas well.Research has been conducted to explore the mechanism of gas-liquid-solid three phase flow in water-producing gas well,and analyzed the flow pattern accordingly.On the basis of VOF multiphase flow model and the software Fluent,we accomplished the numerical simulation research about three phase flow in the wellbore of water-producing gas well under given conditions,and proved characteristics and distribution rules of flow patterns in three phase flow.Experimental research on sand-carrying pattern of water-producing gas well has been conducted using the method of combining wellbore sand-carrying experiment and numerical simulation.Through wellbore sand-carrying experiment,quantitative analysis could be made about the influencing elements of sand-carrying process in gas well,and direct observation could be fulfilled about the movement of sands in water-producing gas well.Considering the reality of water-producing gas well,force analysis of sands is made,and sand-carrying terminal velocity model of water-producing gas well is also built up.On the basis of conclusions made through wellbore sand-carrying experiment,the formulas of critical sand-carrying velocity in water-producing gas well are thus obtained.