Vibration Analysis And Layout Optimization Of Surface Fracturing Manifold

In recent years,due to the increasingly serious problems of energy and ecological environment,China has gradually turning its attention to shale gas because of its cleaner and reserves,hydraulic fracturing technology is widely applied to its extraction process as the key technology to improve the shale gas production.In the high pressure fracturing site,the pulsating fluid with non-uniform flow velocity in the fracture manifold generates a time varying exciting force on the tube wall,which results in the coupling vibration of the manifold.When the vibration intensity is too large,it will seriously affect the service life of the fracturing pipe,and has a serious hidden danger to the safety of the construction site.In order to solve the problem of excessive vibration intensity of the ground fracturing pipe,this paper establishes the dynamic model of fracturing pipe at first,and combined with the Newton method to deduce the nonlinear vibration differential equation of bending,and the equation is discretized,the differential equations of motion of elbow is simplified,and obtained the main factors affecting pipeline vibration.According to the actual working conditions and layout of the fracturing site,the boundary conditions of the elbow are given,it lays the foundation for the establishment of the simulation model of the fracturing pipe vibration.Based on the fluid solid coupling theory,the finite element model of the vibration characteristics of the pipeline is established by using the finite element software,and the reliability of the method is verified by comparing with the measured data.The finite element method is used to analyze the influence of the factors on the bending strength of the tube under the same working condition because of the single factor changes lead to the factor of multi factor coordination?The calculation results show:In order to reduce the vibration intensity of the fracturing pipe,the angle of the double elbow connection should be controlled between 75° and 105°;When the working pressure is 60MPa,the displacement of fracture fluid is 15m3/min,the pipes with inner diameter of 3in and its mating components should be selected;Increasing the wall thickness can reduce the vibration intensity of the pipeline but not more than 21mm.In this paper,based on the influence of various factors on the vibration characteristics of the pipeline,a new type of ground fracturing pipe layout scheme is proposed on the basis of the existing ground fracturing pipe layout,the finite element method is used to analyze and compare the existing layout scheme and the new layout scheme,the feasibility of the new layout scheme of ground fracturing pipe in vibration suppression is determined.On the basis of verifying the feasibility of the new pipe layout scheme,the supporting method and supporting position of each fracture pipe are analyzed in detail,It provides a theoretical basis and technical support for the layout of the fracturing pipe in the field.