超声衰减谱法测量含蜡原油中蜡晶粒度

Particle size characterization of wax crystal in crude oil by ultrasound attenuation spectroscopy

利用超声衰减法测量了不同频率不同温度下南海原油、丘陵原油和白油中的声衰减系数。同时,结合超声耦合相模型(Harker-Temple模型)和声散射模型(Bouguer-Lambert-Beer-Law模型)进行了数值研究,模拟出油样在两个不同频率下的声衰减系数以及它们的比值随蜡晶粒度的变化关系,较为准确地计算预测含蜡原油中声衰减系数。经过比较理论预测获得的声衰减模型与实验获取的声衰减系数,计算出了原油中所含蜡晶在不同温度下的平均粒度大小。结果表明,随着温度的降低,蜡晶的平均粒度大小呈增大趋势。测量结果与显微镜法测量所得结果进行对比,表明此方法应用到含蜡原油中蜡晶粒度大小的测量是可行的。

The ultrasonic attenuation coefficients of Nanhai oil, Qiuling oil and white oil are measured under different frequencies and different temperatures. At the same time, the numerical study is made by combining the ultrasonic coupled phase model （HT model） and the Bouguer-Lambert-Beer-Law （BLBL model） scattering model to simulate the relationship of the variation of the ultrasonic attenuation coefficients and their ratio with the particle size of wax crystal in oil samples under two different frequencies. Then the ultrasonic attenuation coefficients of waxy crude oil could be predicted rather accurately. Average particle sizes of wax crystal at different temperatures are determined by comparing the attenuation model obtained by theoretical prediction with the ultrasonic attenuation coefficients measured by expe- riments. It is found that as temperature decreases, the average particle size of wax crystal increases monotonically. Comparing these results with those measured by microscope shows that this method might be feasible for monitoring the average particle size of wax crystal in crude oil.