Abstract:
During the perforation operation of hydraulic sand blasting fracturing with large displacement and high sand ratio, sand-carrying fluid flowing at high speed will cause serious erosion damage to the surface of the jet tool. Based on the jet erosion experiment on 35CrMo steel, which is the body material of the jet tool, a semi-empirical erosion calculation model was obtained. Combining with DPM numerical simulation method, the distribution of liquid-solid two-phase flow field and the wall erosion rate in the tool in the perforating process are obtained. The effects of liquid and solid particle parameters on the particle content when flowing through the nozzles at upstream and downstream and on the erosion damage at the inlets of the nozzles were discussed.The results show that the particle content in downstream nozzles is larger than that in upstream nozzles when the flow inside the tool remains stable, the erosion damage at the inlet of downstream nozzles is more serious, and the difference of particle content and erosion damage is more serious when using high viscous liquid with large displacement and large-diameter particles with high-density. In order to prevent the perforation efficiency from being greatly affected by the difference of particle content between in upstream and in downstream nozzles, it is recommended to use high-viscosity fracturing fluid with good sand-carrying property and small-diameter particles with low density in the actual production process to control construction displacement when guaranteeing operation efficiency and tool life.