聚合物驱稠油采出液处理剂研究

Development of treatment agents for heavy oil produced fluid by polymer flooding

针对渤海油田聚合物驱稠油采出液,研究了聚合物对其稳定性影响;合成了不同结构原油破乳剂和絮凝剂,讨论了药剂结构对处理效果的影响;研制出了一种原油破乳剂和一种絮凝剂。结果表明:(1)随着聚合物浓度的升高,原油乳状液中水珠直径与污水中油珠直径都逐渐变小,同时污水中油珠的Zeta电位逐渐升高;(2)具有分支结构的原油破乳剂脱水率比具有线性结构的原油破乳剂脱水率高,具有星形结构的原油破乳剂脱水率比具有梳状结构的原油破乳剂脱水率高;(3)针对该污水体系,絮凝剂的最佳合成条件为单体质量浓度为1%、阳离子度为40%、反应温度为5℃,引发剂浓度为0.15mmol·L-1;(4)破乳剂FA01在脱水温度为70℃,用量为200mg·L-1,脱水时间为60min条件下,脱水率达到86%;(5)絮凝剂WS05在温度为60℃,用量为50mg·L-1,时间为30min条件下,能将含聚污水中含油率降到50mg·L-1以下。

The influence of polymer on the treatment of water-in-oil emulsion and produced water by polymer flooding from Bohai sea oilfield of China has been studied. The influence of molecular structure of demulsifier on the demulsification performance and the influence of synthesis condition of flocculent on the treatment performance have been studied for heavy oil produced fluid from that oilfield. A kind of demulsifier and a kind of flocculent have been developed, and the effect has been tested in the oilfield. The results revealed that with the increase of polymer concentration, both water drops in crude oil emulsion and oil drops in produced water get smaller and smaller, meanwhile, the zeta potential of oil drops in produced water get higher and higher. All of that lead to the difficulty of treatment of heavy oil produced fluid involving polymer. The dehydration ratio of the demulsifier with branched structure is higher than that of the demulsifier with linear structure, and the dehydration ratio of the demulsifier with star-like structure is higher than that of the demulsifier with comb-like structure. For heavy oil emulsion by polymer flooding in Bohai sea oilfield, the dehydration ratio of the demulsifier which named FAO1 is 86%, under the condition that the temperature is 70℃, the time is 60 minutes, and the concentration of FA01 is 200mg·L-1. The optimum synthesis condition of the flocculent for the produced water is that the concentration of monomers is 1%, the cation monomer ratio is 40%, the polymerization temperature is 5℃, and the concentration of the initiator is 0.15mmol·L-1. For the produced water, the oil concentration can be reduced to 50mg-L-1 by the flocculent which named WS05, under the condition that the temperature is 60℃, the time is 30 minutes, and the concentration of WS05 is 50mg·L-1.