针对塔河油田超深井稠油掺稀生产过程中存在的稀油不足、经济性差等问题,提出蒸馏轻组分回掺+热裂解改质开采方法。一方面,进行稠油蒸馏循环掺稀实验,确定轻组分油循环回掺的可行性;另一方面,将蒸馏后的重组分油进行热裂解改质,降黏至满足外输要求。结果表明：循环掺稀实验中,采用350 ℃蒸馏得到的轻组分收率稳定在27 %左右,掺稀比稳定在0.39∶1,说明轻组分循环掺稀可行;热裂解改质实验中,蒸馏得到的重组分在380 ℃条件下反应60 min后,黏度从398 800 mPa·s降低至1 704 mPa·s,已能满足长距离输送要求,且密度从1.001 8 g/cm ³降低至0.991 1 g/cm ³,实现了稠油轻质化。该方法实现了稀油轻组分的循环利用,大幅减少了稀油用量,同时实现了稠油提质增效,为超深井稠油高效开发提供了新思路。

Due to the lack of dilute oil and the poor economical benefit in the dilution process of heavy oil in ultra-deep wells of Tahe Oilfield, the mixed oil is treated by dilute oil recycling combined with high-temperature thermal cracking process. For one thing, the experiment of dilute oil recycling after heavy oil distillation is carried out to determine the feasibility of cycling of light component oil. For another thing, the viscosity of the heavy components is reduced to meet the requirement of external transportation. The results show that when in the dilute oil recycling experiment, the light component yield obtained by distillation at 350 ℃ is stable at about 27 %, and the dilution ratio is stable at 0.39∶1, which indicates that dilute oil recycling is feasible. While in the modification experiment by thermal cracking, after the heavy components obtained by distillation reacting at 380 ℃ for 60 minutes, the oil viscosity can be reduced from 398 800 mPa·s to 1 704 mPa·s, which means it has met the requirement of long-distance transportation, and the density can be reduced from 1.001 8 g/cm ³ to 0.991 1 g/cm ³. Therefore, the lightening of heavy oil is realized. This method not only greatly reduces the amount of dilute oil by the recycling utilization of light oil, but also improves the quality and utilization efficiency of heavy oil. It provides a new idea for the efficient development of heavy oil in ultra-deep wells.