A Study On The Law Of Unstable Flow In Foam Generator And Structure Optimization

As oil fields in eastern China getting into the late stage of development, large amount of sand production during production process is the main obstacles to improve the oil recovery rate.In order to provide theoretical basis for sand washing bubble production and development of the key process equipment,the paper analyzes the structure characteristics and working principle of the bubble generator at home and abroad.According to the actual production situation of oil fields, the paper designs a continuous and efficient foam generator based on the concentric tube type foam generator. The paper introduces how the foam generator works and simulate the inner flow field with computational fluid dynamics software.By changing the angle at the top of the pipe trachea and the trachea to inlet diameter cavity distance to achieve the change of flow field,we obtain the best structure parameters of foam generator.Based on the internal velocity, pressure, flow and outlet section gas phase volume distribution, the paper comprehensively analysis the changing of structural parameters on the internal flow field of foam generator.Because the PIV velocimetry is intuitive and does not disturb flow field, the paper collects the data of gas-liquid two-phase flow field in the foam generator by PIV velocimetry. First, we make sure the parameters of the gas-liquid two-phase flow in the foam generator, and build the experimental model of foam generator; Then, we use PIV velocimetry to collect different liquid flow rate,gas inlet pressure and concentration of foaming agent and so on.The paper analysis the influence of factors on flow state in generator and the thickness of foam fluid layer, and then get the most effective factor for gas-liquid mixing and foaming performance. We make a stability test on the foam generated by different experimental conditions,making sure of the half-life period of the foam, and analysis the stability of the foam under different experimental conditions. We shoot the motion process of bubbles in the generator under different gas inlet pressure by using the high speed camera,and get the effects of different gas inlet pressure on collision and coalescence of bubbles.