稠油表面活性剂乳化降黏效果及其作用机理研究——以渤海BZ25-1s油藏为例

Emulsification Process and Mechanism of Surfactants Used in Heavy Oil:Taking BZ25-1s Reservoir in Bohai Area as an Example

针对渤海BZ25-1s油田储层地质特征和流体性质,在不同实验方法条件下,以油水乳状液黏度、乳状液结构形态、分水率和界面张力为评价指标,开展了稠油表面活性剂乳化降黏效果及相关作用机理的实验研究。结果表明,当油水体积比低于7∶3和乳化药剂浓度高于600 mg/L时,强化分散体系可以与原油作用形成水包油型(O/W)乳状液,降黏率可达80%。相对于强化冷采体系,强化分散体系在破乳、降低界面张力及抗吸附方面均具有显著优势,其与原油乳化作用可以导致部分表面活性剂组分进入原油中,进而影响强化分散体系与原油间界面张力和乳化效果。强化分散体系能更大幅度降低注入压力、减缓含水率上升速度,并且能更有效地提高原油采收率。

Aiming at the reservoir geological characteristics and fluid properties of BZ25-1s oilfield in Bohai reservoir,taking diversion ratio,interfacial tension,viscosity and structure of the emulsion as evaluation index,the reducing viscosity effects of emulsification and its related mechanism were studied.The results showed that,when the ratio of oil and water was less than 7∶3,and the concentration of emulsion agent was higher than 600 mg/L,the intensified disperse system could form emulsion liquid with crude oil,and its ratio of reducing viscosity could reach 80%.Compared with the intensified cold production system,the intensified dispersion system had a significant advantage in demulsification,reducing interfacial tension and anti adsorption.The emulsification of this system and crude oil could lead to part of the component getting into the crude oil,which influenced the interfacial tension and emulsification effects between crude oil and the intensified disperse system.The intensified dispersion system can reduce the injection pressure and water content increasing rate,and it can enhance the oil recovery more effectively.