Study On The Characteristics Of Liquid Loading In Condensate Natural Gas Pipes

Liquid loading has always been an important issue in production of condensate gas wells and gathering pipelines.In the operation of condensate natural gas pipelines,changes in temperature and pressure may lead to the emergence of condensate.When the liquid phase in the condensate natural gas pipes cannot be carried out,coupled with the effect of gravity,the liquid phase will accumulate in the bottom of the pipelines,thereby forming a liquid loading,affecting the transport efficiency of the condensate gas pipelines,or even security of the entire pipelines.In addition,since the development and production of condensate gas wells are often accompanied by the production of condensate oil and/or water,after the development of condensate gas fields and the high production period of condensate gas wells,the bottom-hole pressure and gas production will gradually decrease,and the capacity of liquid-carrying will also decline.When the gas in the well cannot carry all the condensate and water to the outside of the well,these liquid phases will accumulate at the bottom of the well to form liquid loading,which will affect the gas well production and even cause the gas well to stop production.Therefore,it is of great significance to study the flow of liquid loading in condensate gas pipelines and the critical liquid-carrying flow of condensate gas wells for the safe operation,production,and efficiency improvement of gas pipelines and wells.In this paper,Fluent is used to simulate the effects of pipe diameters,initial liquid loading volume,pipeline inclination angle,and properties of liquid loaded on the onset of liquid loading in condensate natural gas pipes under 500 operating conditions.From the simulation results,the following conclusions are obtained: Changes in the inclination angles and diameters of the pipelines will have a greater impact on the critical gas velocity,followed by changes in the kinematic viscosity of the liquid loaded,and the changes in the initial liquid loading volume will have the least impact on the critical gas velocity.In addition,based on the energy conservation equation,a functional relationship between the droplet deformation parameters and the critical Weber number is derived.From the perspective of the droplet's force balance,a prediction model of critical liquid-carrying flow for condensate gas wells about deformation of the droplet in the process of being carried and deviation angel is established.Combined with actual production data for verification,and compared with other existing 6 critical liquid-carrying prediction models.The new predictionmodel proposed in this paper has the highest prediction accuracy in different condensate gas field blocks,which is more in line with actual production.