Study On Erosion Wear Of The Pressure Regulating Device In Throttle

Throttling tube is necessary equipment for preventing well kick and providing pressure control in oil and gas well production.Due to the complexity of operating conditions and internal flows,the major pressure reduction equipment-Needle valve was struck by fluid carrying a large amount of solid impurities,which caused erosion wear.Corrosion pit,crack,appear on the valve wall of needle type throttle valve.In serious when can cause the valve core body piercing the throttle manifold overall failure,affect production progress at the same time there is a security risk.In this paper,the erosion wear problem of needle throttle valve is studied.Firstly,the internal mechanism of the erosion wear phenomenon is introduced,and the relationship between the particle flow state,property,shape and erosion wear is summarized,and the main influencing factors are determined.Secondly,based on the erosion wear prediction equations obtained from different experiments,the curves of erosion rate,impact Angle and velocity were drawn,and the most suitable prediction equation was selected.Thirdly,the force state of particles in the fluid and the motion process after the collision with the wall surface were analyzed,the basic equations of solid-liquid two-phase flow were reviewed,and the discrete phase theory was finally selected to study the erosion wear of the needle valve.Then,according to the actual size of needle valve,physical model is established,grid is divided,boundary conditions are set and solution methods are proposed.Finally,according to the specific simulation results,the particle movement rule is analyzed and studied,the valve core and valve body structure are changed,and the erosion wear situation is compared.The final conclusion of this paper is as follows: the fluid dominates the particle movement process,when the fluid velocity is greater than the particle velocity,the fluid accelerates the particle motion,otherwise it is decelerated motion;The decrease of particle velocity is mainly due to the deceleration of fluid.With the increase of opening degree,tThe erosion rate of the needle valve is gradually reduced,and the erosion position of the spool is close to the spool tip with the increase of top Angle degree.When the valve body structure does not change,25° is the optimal number of spool angles;Changing the angle of the bottom surface of the valve body can effectively reduce the maximum erosion rate of the valve body and the valve core,and finally determine the top angle of the valve core 30° and the bottom surface.The combination of angles of 55° is the optimal throttle structure parameter.In summary,the obtained research results provide an important basis for the design of the needle valve structure.