Numerical Simulation Study On The Improvement Of Liquid-carrying Capacity Of Gas Wells By Coupling Eddy Current Tools In Down-hole Of Natural Gas

As the gas well is continuously mined,the liquid carrying capacity is reduced,and the liquid generated in the wellbore cannot be carried out of the wellhead,and it is retained in the wellbore to form wellbore effluent,which seriously affects the normal exploitation of the gas well.It is necessary to adopt the corresponding liquid discharge gas production technology to make the gas well To resume production.The eddy current tool is a new and efficient drainage and gas recovery technology,which is widely used in various atmospheric wells to solve the problem of wellbore effusion.However,in order to enable the eddy current tool to be smoothly lowered and installed into the wellbore,a gap must be left between the vortex tool and the oil pipe.The existence of the gap makes the eddy current tool unable to fully exert the swirl separation effect and reduce the liquid carrying efficiency of the eddy current tool.Based on the above problems,this paper proposes and studies a coupling type eddy current tool,which is characterized in that the structural component is changed to be installed in the oil pipe in the form of a coupling,thereby effectively solving the problem of the gap between the eddy current tool and the oil pipe,and improving the eddy current tool.Liquid carrying efficiency.In order to further clarify the effective mechanism of the coupling vortex tool to improve the liquid carrying capacity,the following aspects are studied by combining theoretical analysis,numerical simulation and laboratory test:Firstly,the theoretical analysis of the force model of the droplet and the liquid film is carried out from the angle of the lowest critical liquid carrying flow rate,and the principle of liquid carrying of the coupling type eddy current tool is clarified.The numerical simulation method is used to analyze the internal flow field and the liquid carrying efficiency of the coupling eddy current tool.The results show that the fluid rapidly forms a swirling flow under the action of the swirling guide of the vortex tool to make the fluid flow state.The turbulent flow changes to a spiral annular flow,which reduces the pressure loss gradient in the oil pipe.The formation of the gas core increases the axial velocity of the natural gas.The formation of the liquid film changes the liquid carrying mode of the natural gas and reduces the minimum critical liquid carrying.The flow rate can effectively improve the liquid carrying capacity of the gas well and reduce the wellbore effusion.Secondly,the numerical simulation method is used to investigate the influence of the structural parameters of the eddy current tool on the gas-liquid phase distribution,axial velocity,tangential velocity and pressure loss in the external flow field,and determine the influencing factors of the eddy current tool carrying efficiency.The vortex region appearing at the end of the eddy current tool is proposed and designed to reduce the formation of the vortex region.The results show that the smaller the vortex cone angle is,the better the vortex region is.Considering the comprehensive influence of multiple factors on the liquid carrying efficiency,the orthogonal optimization scheme is designed to optimize the structure of the eddy current tool,and the significant influencing factors of the liquid carrying efficiency and the optimal structural combination parameters are determined.The adaptability of the eddy current tool under different working conditions is analyzed.It is concluded that the eddy current tool has higher liquid carrying efficiency in the high gas-liquid ratio k and high flow rate v conditions.Finally,using the experimental research method,the liquid carrying characteristics of the three groups of eddy current tools in the optimization results were studied in the laboratory.The data showed that increasing the gas flow rate and reducing the liquid flow rate can improve the liquid carrying efficiency of the eddy current tool.The three sets of eddy current tools are analyzed under the same working conditions.The optimal turbulent tool combination of the optimal structural parameters has the highest liquid carrying efficiency and the lowest pressure loss.The optimal structural parameter combination of the coupling eddy current tool is determined,and the simulation analysis is verified.Correctness and effectiveness.