破乳剂对模拟油田二元复合驱采出水的作用机理

针对破乳剂成分与结构对油田采出水破乳脱稳的影响机制仍不明确的问题,依据新疆油田二元驱实际采出水组成配制模拟二元复合驱采出水,考察有机破乳剂种类和结构及无机电解质对其破乳脱稳的影响.结果表明,合成有机破乳剂的起始剂种类对破乳脱稳的影响较大,起始剂含量具有一定影响,而EO/PO比的影响相对较小.PAC和Al2(SO4)3的破乳脱稳效果最好,投加量500 mg/L时均能将剩余含油量降低到10 mg/L以下;而FeSO4和ZnSO4次之,NH4Cl较差.破乳剂通过电性中和及与HPAM形成的协同絮凝作用,促进了油滴的碰撞聚并,达到了较好的破乳脱稳效果.

Process mechanisms of simulated polymer/surfactant oilfield produced water treated by demulsifiers

For the problem of unclear process mechanisms of oilfield produced water treated by demulsifiers, simulated polymer/surfactant produced water was prepared according to the practical component of produced water from the polymer/surfactant flooding process in Xinjiang Oilfield. Effects of different types of organic demulsifiers and inorganic electrolytes on the demulsification and destabilization of the simulated produced water were investigated. Results show that the initiator type of organic demulsifiers had a greatly influence on the demulsification and destabilization process, corresponding with some minor influences for the initiator content and very slightly effect for the EO/PO ratio of organic demusifiers. PAC and Al2(SO4)3 could lead to the best oil-water separation efficiency as the residual oil content was less than 10 mg/L at dosage of 500 mg/L. The demulsification efficiency as using FeSO4 or ZnSO4 was also good, but was worse by NH4Cl. By interfacial charge neutralization for facilitating collision and coalescence of oil droplets and the synergistic effect of flocculation with HPAM in the O/W emulsion, demulsifiers could efficiently promote the demulsification and destabilization process.