基于溶解速率和降黏率的稠油掺稀降黏实验

Experimental Research of Dilution Technique of Viscous Crude Based on Dissolution Rate and Viscosity-Reducing Rate

针对稠油掺稀降黏工艺存在稀释剂利用效率低问题,以新疆油田J7井、TK675X井和FZ010井稠油油样及柴油和凝析油两种稀释剂为研究对象,考察温度和稀释剂对稠油溶解速率的影响及稀释剂对稠油的降黏效果。J7、TK675X和FZ010稠油在50℃下的黏度分别为524.5、4337.3和139836.6 mPa·s。结果表明,稀释剂中稠油的质量浓度在0~1200 mg/L时,质量浓度和混合油吸光度呈良好的线性关系,标准曲线的拟合相关度均大于0.99。三种稠油在稀释剂中的溶解速率均随着温度升高而增大。温度从30℃增至80℃,稀释剂为柴油时,J7、TK675X和FZ010稠油溶解速率分别由44.3、5.4和28.3 mg/(m2·s)增至413.9、171.2和201.8 mg/(m2·s);稀释剂为凝析油时,J7、TK675X和FZ010稠油溶解速率分别由224.7、110.8和168.3 mg/(m2·s)增至994.1、450.1和371.8mg/(m2·s)。在相同温度下,J7稠油的溶解速率大于TK675X和FZ010稠油;凝析油对三种稠油的溶解速率均大于柴油。掺稀混合油的黏度随着掺稀质量比的增大而显著减小。稀释剂为柴油时,J7、TK675X和FZ010稠油在掺稀比为0.4、0.3和0.2时的降黏率分别为90.54%、92.59%和96.04%,稠油黏度越大,掺稀降黏效果越显著。稀释剂为凝析油时,混合油的黏度随掺稀比的变化规律与掺柴油时基本一致。相同掺稀比下,稠油掺凝析油的降黏率大于掺柴油。从提高稀释剂溶解效率和降黏率两方面考虑,凝析油更适宜作为三种稠油的稀释剂。

In allusion to the low efficiency of utilizing diluents,taking heavy oils in J7,TK675 X and FZ010 wells of Xinjiang oilfield and two kinds of diluents(gas condensate and diesel)as research objects,the influences of temperature and diluents on dissolution rate and reduction of viscosity were studied. The viscosities of J7,TK675 X and FZ010 at 50℃ was 524.5,4337.3 and139836.6 mPa·s,respectively. Research results showed that when the mass concentration of heavy oil in diluent was range from 0to 1200 mg/L,it was in good linear relationship with absorbance of oil mixture,and the fitting relevancy of standard curve was greater than 0.99. The dissolution rates of three heavy oils in diluents increased with increasing temperature. When diluent was diesel,the dissolution rate of J7,TK675 X and FZ010 increased from 44.3,5.4 and 28.3 mg/(m2·s)to 413.9,171.2 and 201.8 mg/(m2·s)respectively with temperature raising from 30℃ to 80℃. And when diluent was gas condensate,the dissolution rate of J7,TK675 X and FZ010 increased from 224.7,110.8 and 168.3 mg/(m2·s)to 994.1,450.1 and 371.8 mg/(m2·s)respectively with temperature raising from 30℃ to 80℃. At the same temperature,the dissolution rate of J7 oil was greater than that of TK675 X and FZ010 oil. Dissolution rates of heavy oils in gas condensate were higher than those in diesel. The viscosities of oil mixture were dramatically decreased with increasing mass ratio of oil to diluents. When the diluent was diesel,the viscosity-reducing rate of J7,TK675 X and FZ010 was 90.54%,92.59% and 96.04% with 0.4,0.3 and 0.2 mass ratio of oil to diluent,respectively. The higher viscosity of heavy oil,the more significant viscosity-reduction effect was. When the diluent was gas condensate,the rule of viscosity reduction was similar to that in diesel. Viscosity-reducing rates of heavy oils mixed with gas condensate were higher than that with diesel at same mass ratio of oil to diluent. So it was more appropriate for gas condensate as the diluent in terms of dissolution rate and viscosity-reducing rate.