扶余原油乳化生成条件与驱油机理

Formation Condition of Emulsion and Oil-displacement Mechanism in Fuyu Oilfield

宣英龙 杨雪白 秦笃国 王树坤 张永琪

XUAN Yinglong YANG Xuebai QIN Duguo WANG Shukun ZHANG Yongqi

为提高扶余油田中低渗普通稠油油藏原油采收率，开展了乳化降黏技术研究，考察了乳化剂加量、油水体积比和剪切速度对所形成的乳状液状态与性能的影响，研究了相同黏度聚合物段塞和乳化剂/聚合物二元段塞的驱油效率，分析了乳化复合驱提高采收率的机理。结果表明，随着乳化剂质量分数增大，乳液黏度先减小后增 大，乳液粒度逐渐减小；对于扶余稠油，乳化剂最佳质量分数为0.3%，在此条件下，油水体积比低于55∶45 时可产生O/W型乳液；随剪切速度增大，乳液黏度先降低后增加，剪切速度为45 cm/min 时乳液为O/W型，剪切速度为450 cm/min 时乳液变为W/O 型；水驱后分别注入聚合物和乳化剂/聚合物二元段塞，采收率分别提高10.5%和25.4%。乳化复合驱不仅能扩大波及体积，还能降低油水界面张力，乳化原油，提高驱油效率。图8 表2 参16

In order to enhance the recovery of heavy oil reservoir with middle and low permeability，emulsifying and viscosity reducing technology was developed. The effect of emulsifier concentration，oil-water ratio and shear rate on the state and performance of emulsion was evaluated. Oil displacement efficiency of polymer slug and emulsifier-polymer slug which had the same viscosity was studied，and the mechanism of enhancing oil recovery by combination flooding was analyzed. The experiment results showed that the viscosity of emulsion decreased first and then increased with the increase of emulsifier concentration，while the droplet size of emulsion became smaller gradually. For Fuyu heavy oil，the optimum mass fraction of emulsifier was 0.3%. O/W emulsion could be triggered when oil-water ratio was lower than 55∶45. With increasing shear rate，the emulsion viscosity decreased first and then increased. When the shear rate reached 45 cm/min，the emulsion completely became O/W，however，when the shear rate reached 450 cm/min，the emulsion completely became W/O. When polymer slug or emulsifier-polymer slug was injected after water flooding，the recovery was improved by 10.5% or 25.4% respectively. Emulsifier-polymer flooding could not only enlarge sweep efficiency，but also reduce interfacial tension，emulsify crude oil and enhance oil recovery.

10.19346/j.cnki.1000-4092.2016.06.023