蒸气开采过程中金属盐对稠油粘度及平均分子量的影响

探讨了在注蒸气条件下，稠油的粘度和平均分子量随蒸气温度、反应时间的变化规律，研究了金属盐、油层矿物对稠油水热裂解反应的影响。实验结果表明，在注蒸气的条件下，辽河稠油可以发生水热裂解反应。金属盐的存在，可以加速稠油的水热裂解反应，从而导致粘度和平均分子量的进一步降低，使稠油的粘度由原始的124.5 Pa·s下降到32.4 Pa·s，下降了74.0%，平均分子量由反应前的654下降到398。高温下油层矿物对水热裂解反应有促进作用，在反应体系中，在有水时加入质量分数为10%的油层矿物时，稠油的粘度由原始的124.5 Pa·s下降到82.5 Pa·s，下降了33.7%。在蒸气条件下，在金属盐和油层矿物共存时，稠油粘度由124.5 Pa·s下降到26.8 Pa·s，下降了78.5%。这为实现井下催化降粘开采稠油提供了理论依据。

EFFECTS OF METAL SALTS AND MINERAL ON VISCOSITY AND MOLECULAR WEIGHT OF HEAVY OIL UNDER STEAM CONDITION

The change of viscosity and average molecular weight of heavy oil from Liaohe oilfield with temperature and reaction time are investigated in the paper. The effect of metal salts and reservoir minerals on the aquathermolysis of the heavy oil are also studied. The results show that Liaohe heavy oil can undergo aquathermolysis in steam injection process. It is found that the metal salts can accelerate the aquathermolysis of heavy oil and lead the viscosity and average molecular weight decrease further. The reservoir minerals have the synergetic effects on the aquathermolysis of the heavy oil. The results provide a theoretical basis for down-hole catalytic upgrading of heavy oil.