Structural Performance Analysis And Optimization Of Horizontal Well-staged Fracturing Ball-sliding Sleeves

Horizontal Wells staged fracturing is the main way of exploitation of low permeability reservoirs mining,ball actuated sliding sleeve which is the core of the staged fracturing tools,placed between two open hole packer,for the purpose of interval provides the fracturing and oil(gas)channel.In high temperature and high pressure working environment,the disadvantage of ball actuated sliding sleeve affects the effect of staged fracturing,such as:the unreliable switch,poor sealing performance,easy to be blocked,tee erosion wear,etc.This paper first analyzes the stress of the horizontal well staged fracturing string and failure situation,calculate the mechanical model of different working time.The string mechanical model of different working time is deduced,and the safety evaluation standard of ball actuated sliding sleeve is established.Then according to the failure characteristics of ball actuated sliding sleeve,designed a new sliding sleeve which has strong sealing and erosion resistance,such as:add circlip reverse locking mechanism;change the single sealing ring seal to O sealing ring + double C baffle ring seal;change the single cone ball seat to tee with former cone surface;change the cross section shape of the sand blasting hole to isosceles trapezoid.And using the finite element software Abaqus to analyze open process?tee drilling process?dynamic seal process of sliding sleeve.Then the force analysis of the main parts of the ball sliding sleeve is carried out,and the strength check of the main parts of the ball sliding sleeve is completed by the finite element simulation.To solve the problem of sealing failure,this paper introduced theoretical model of cones and cambers maximum contact pressure within the discharge of fracturing balls and the seats sealing.Simultaneously,static on the cones and cambers was achieved by means of finite element method.Then the erosion wear equation of solid liquid two phase flow is established,the erosion wear rate of the curved tee with former cone surface and double cone tee are analyzed.Proved tee with former cone surface has higher erosion resistance than the double cone tee,and geted the distribution regularity of the pressure field?velocity field?the mass fraction of solid phase particles.Finally using the PIANO integrated optimization software to optimize the curved central angle and taper cone,under the optimization goal that curved average erosion wear rate is minimal,getting the optimal parameters of the curved central angle and taper cone.the optimal structure parameters of new curve ball seat:?=R;?=30°;?y=90°-arcsin(d/2R)?The new sliding sleeve can achieve 16 level staged fracturing,and has a good sealing and erosion resistance,can improve the effect of horizontal well staged fracturing.