【作者】 谭晓飞；

【导师】 谭蔚；

【作者基本信息】 天津大学 ， 化工过程机械， 2007， 硕士

【摘要】 为了研究超声波对原油乳状液破乳的影响,本文对原油乳状液的流变性进行了测定,并分别采用热化学法和超声化学法进行了破乳实验研究。研究内容主要包括:含水率、剪切速率、温度对原油乳状液流变性的影响;系统分析了温度、破乳剂用量、超声功率、超声辐射时间、含水率等可控因素对原油乳状液破乳脱水的影响。研究结果表明,原油乳状液的粘度先随含水率的增加而增加,到达转相点后又降低。温度对原油乳状液的粘度有较大的影响,随着温度的升高,原油乳状液的粘度降低,不同剪切速率下的粘温曲线由分散逐渐汇于一点。原油破乳时,脱水率随温度升高而增加,随沉降时间的增加而增加,但是趋势渐缓。采用超声辐射破乳时,超声功率和超声辐射时间是影响破乳的重要因素。脱水率先随超声功率增大而上升,到空化阈值后再减小;超声辐射时间存在一个最佳时间,超过最佳时间后脱水率反而下降。无论是热化学法破乳还是超声化学法破乳,脱水率都随破乳剂用量的增加而先增加后减小,即破乳剂用量存在一个临界值,这个临界值与原油乳状液和破乳剂的性质有关。经过实验分析,对于本实验用原油乳状液,采用热化学法破乳时,在加热温度为75℃、破乳剂用量为100 mg/L、沉降时间为200 min条件下,脱水率可达96.45 %;采用超声化学法破乳时,在加热温度为75℃,破乳剂用量为50 mg/L,超声功率为100 W,超声辐射时间在10~30 min之内,沉降时间为60 min时,脱水率可达97.65 %。实验结果表明超声波对原油乳状液有着良好的适应性,不但可以提高脱水速率、减少沉降时间,还可以提高破乳剂的作用效率,减少破乳剂的用量,是一种有效的油水分离方法。超声波对高含水量的原油乳状液破乳脱水效果好于低含水量的原油乳状液。本文的研究结果,为油田原油脱水工艺的改进提供了一定的理论基础和实验依据。更多还原

【Abstract】 The Rheologic properties of the crude oil emulsion and demulsification on it with the methods of thermo-chemical and ultrasonic chemical were studied in this paper. The effects of water content ratio, shear rate and heating temperature on the rheologic properties of crude oil emulsion were analyzed. The effects of the demulsification were investigated with some controllable factors changed, including temperature, demulsifier dosage, ultrasonic power, irradiating time and water content.The results show that the viscosity of the crude oil emulsion increases with the raise of the emulsion water content at initial stage, and it begins to decrease after the phase inversion point. The temperature of the crude oil emulsion can greatly influence its viscosity, and with the increase of temperature the viscosity declines. In addition, viscosity-temperature curve gradually converges to s point from divergence at varied shear rate. The dehydrating ratio of crude oil emulsion ascents according as the raise of temperature and sediment time though the tendency becomes slow gradually. The ultrasonic power and irradiating time are the two most important factors which can affect the dehydrating ratio of the emulsion. Both of the ultrasonic power and irradiating time have an optimum range against the crude oil emulsion used in this paper. The dehydrating ratio declines when these two factors exceed the respective optimum range. Demulsifier dosage also has a critical concentration. In the end, the dehydrating ratio of crude oil emulsion increases with the ascent of demulsifier dosage until a certain point, namely it also has a critical concentration. Exceed this point the dehydrating ratio falls down. This phenomenon is not only applicable for the thermo-chemical method but also the ultrasonic chemical technology.For the crude oil emulsion used in this experiment, the dehydrating rate can reach about 96.45 % for the thermo-chemical method under the conditions of 75℃of heating temperature, 100 mg/L of demulsifier dosage and 200 min settling time. But for the ultrasonic chemical method, the best dehydrating rate was about 97.65 % when the conditions were 75℃of heating temperature, 50 mg/L of demulsifier dosage, 100 W of ultrasonic power, 10~30 min irradiating time and 60 min settling time.The results show that ultrasonic has good flexibility on crude oil emulsion. It can not only increase the speed of demulsification and reduce the settling time but also improve the efficiency of demulsifier and cut down the dosage of demulsifier. So it is an effective demulsifying method. The dehydration effect is better for the high water content crude oil emulsion than that of emulsion with lower water content by ultrasonic irradiation.This paper provides a certain partial theory basis and abundant experiment data for the improvement of crude oil dehydration process in oil field.更多还原