Optimization Design And Experimental Study of Self-oscillating Cavitating Jet Descaling Nozzle Based On Cleaning Operation

Abstract

The scale of tubing in polymer flooding and ASP flooding Wells is serious in Daqing oilfield. In order to improve the cleaning effect of tubing, the self-vibrating cavitation jet nozzle was developed and the cavitation jet technology was used to remove scale. In the design of nozzle structure, it is necessary to derive the basic relation that the structure of the oscillating cavity should satisfy when strong resonance is generated, and calculate the key length dimension L1 of the oscillating cavity. The numerical simulation method the different diffusion Angle α and diffusion length L3 nozzle wall under the condition of gas generation rate and axial velocity distribution, determine the optimum size of diffuser. The scale-removing performance test of cavitation jet verifies the performance of self-vibration cavitation nozzle and determines the optimal target distance and injection Angle. According to the reasonable dimension relation of the oscillating cavity when resonance occurs, the length L1 of the oscillating cavity when strong resonance occurs is calculated as 10.4mm. Use Fluent fluid calculation software painted wall gas generating rate, the relationship between the axial velocity curve, determine the diffusion Angle α to 30°, spread long L3 is 2.5 mm, jet cavitation effect is best. The descaling performance test shows that under the inlet pressure of 20MPa, the target distance of 15mm and the injection Angle of 60°, the effective cleaning area is the largest within 1s. The designed nozzle has a reasonable structure and efficient descaling performance.