Research On Flow Characteristics And Wear Rule Of The Horizontal Well Sand Blast

Sand blast is an important component part of the horizontal well fracturing string.In the fracturing of horizontal wells,with the increases of construction displacement,the sand blast wears seriously and eccentric wear appears.Packer is difficult to set down.It even causes the sand blast fracture and failure of fracturing.It is difficult to meet the operational requirements for fracturing.In view of the question that the sand fracturing fluid impacts and wears the fracturing sand blast for horizontal wells,Numerical simulation was carried out by using CFD software FLUENT with dispersed phase model.The simulation of interior flow field of the sand blast is performed by means of Reynolds stress turbulent model,control volume method and SIMPLE arithmetic method.The rules of velocity and pressure distribution cloud,proppant concentration cloud of sand blast inside fluid are gained.Indoor erosion wear simulation experiment equipment is established and erosion wear experiment is performed to 45 steel and 40Cr with different angle.The relation between scour angle and erosion wear rate is obtained.With the obtained empirical constant from erosion wear experiment,the factor of erosion wear model is modified using classic erosion wear theory.The simulation of sand blast wear law is carried out by modified erosion wear model.By means of simulation result,influence of perforation interval flow and tubing eccentric on interior flow field of the sand blast is investigated.The result shows that when the distance between perforation and sand blasting hole was less than 300mm,perforation interval flow has obviously influence on interior flow field of the sand blast and eccentric wear is caused by tubing eccentric under the situation of that sand blasting hole is vertically placed.Numerical simulation results coincide with the field application results and this confirms numerical algorithm.This work provides theoretical base and experiences for further research of the structure characteristics and structural optimization design of the horizontal well fractured sand blast.