CO2混相调节剂驱油机理室内研究

为了深入了解混相调节剂降低CO_2/原油最小混相压力的作用,测试CO_2混相调节剂降低最小混相压力的机理,开展了室内实验,并深入研究调节剂的效果。实验结果表明,混相调节剂可以降低CO_2/原油表面张力、促进CO_2抽提原油轻质组分效果、增加CO_2在原油中溶解度、降低原油黏度的作用;其中,主要的机理为降低表面张力和提高抽提轻质组分效果;当原油中调节剂质量浓度达0.3%以上,气液表面张力消失,达到混相;加入调节剂后,采出端气体突破时,CO_2萃取、抽提轻质烃体积百分数增加14倍以上。调节剂作用机理研究,深入了对调节剂改善CO_2驱油效果的认识,并对进一步筛选和研发新型调节剂具有指导意义。

Experimental Study of the CO2 Miscible Modulator Oil-Displacement Mechanism

In order to look into the function of miscible modulator reduction the CO₂/oil minimum miscible pressure and test CO₂ miscible modulator mechanism to reduce MMP, experimental study has carried out, and then lucubrated the effect of miscible modulator. Study shows that miscible modulator decreases CO₂/oil surface tension, and promotes the effect of CO₂ extraction lightweight hydrocarbon component of crude oil. Meanwhile, miscible modulator increases the CO₂ solubility in crude oil, and decreases crude oil viscosity. The main mechanisms are surface tension decrease and promotes the effect of CO₂ extraction lightweight hydrocarbon component. Gas and liquid surface tension disappeared and achieved miscible when the miscible modulator mass concentration in oil is above 0.3%. Volume percentage of CO₂ exacted after addition of modulator increases more than 14 times as much as pure CO₂ flooding when gas breakthrough in production end. The study of modulator action mechanism deepens understanding of the improvement of the effect of CO₂ flooding by miscible modulator. It has important guiding significance for selection and development of new modulator in further.