油气水多相流广泛存在于油气工业过程.针对现有油气水多相流相含率模型对超声换能器测量信息利用有限这一问题,提出了一种水基分散分层流相含率超声测试模型的优化方法.利用最大粒径模型,研究了水基分散分层流中分散相粒径变化规律,确定粒径-波长比的范围处于中波长区.根据超声脉冲回波法,采用"一发三收"超声换能器测试系统,提出了水基分散分层流中超声扩散衰减的测试方法.在此基础上,结合Faran弹性散射理论,建立了油水分散流含油率超声测试模型.利用换能器渡越时间测量信息,提出了声程波动修正参数,改进了油水分散流中混合声速测试模型,并进一步优化了含气率测试模型.仿真结果表明,水基分散分层流含气率预测平均相对误差和均方根误差分别为0.43%和0.23%,含油率预测平均相对误差和均方根误差分别为3.30%和0.28%,验证了所提出的基于混合声速的相含率测试优化模型的有效性和准确性,为油气水多相流超声测试方法提供理论依据.
Oil-gas-water multiphase flow is pervasive in oil and gas industry processes.However,the current phase fraction model for oil-gas-water multiphase flow limits to fully exploit the measurement information from ultrasonic transducers.To solve this problem,an optimized phase fraction model that employs an ultrasonic testing technique in water-based dispersed stratified flow was proposed.Using the maximum particle size model,the variations in particle size in water-based dispersed stratified flow was studied,and the particle size-wavelength ratio resides within the intermediate wavelength regime was determined.Moreover,a"one-transmitter-three-receivers"test system was adopted based on the ultrasonic pulse-echo method and developed a testing method for ultrasonic diffusion attenuation in water-based dispersed stratified flow.Subsequently,it was integrated Faran's elastic scattering theory to establish an ultrasonic testing model for oil fraction in oil-water dispersed flow.Utilizing time-of-flight measurement information,a modified parameter to account for fluctuations in the ultrasonic propagation path were proposed.This allowed to enhance the testing model for mixed sound velocity in oil-water dispersed flow and further optimize the gas fraction testing model.Simulation results showed that the mean relative error(MRE)and root mean square error(RMSE)for gas fraction prediction in water-based dispersed stratified flow were 0.43%and 0.23%respectively,while the MRE and RMSE for oil fraction prediction were 3.30%and 0.28%respectively.These results confirm the efficacy and precision of the proposed optimized testing model for phase fraction based on mixed sound velocity,thereby providing a theoretical foundation for ultrasonic testing methods in oil-gas-water multiphase flow.